Decreased scalp hair can be due to hairs that are broken, as well as hairs that are shed by the root. Even though medically the focus is on disease states that lead to hair shedding during the anagen and telogen stages of hair growth, probably a more common cause of hair loss is hair breakage. Whether the hair is shed by the root or broken off at the scalp, the end result perceived by the patient is the same. This article deals with causes of hair loss due to hair breakage, initially covering the conditions that lead to abnormal hair shaft formation, followed by conditions due to grooming and chemical processing procedures.
Shed hairs without a hair bulb are considered broken hairs. It is important to evaluate what percentage of shed hairs are telogen hairs and what percentage are broken hairs. This can be accomplished, as described in part one of this series, by having the patient collect all lost hair for 4 consecutive days. Each days hair loss should be placed in a separate plastic bag and labeled as to whether the hair was shampooed on the collection day. These hair bags can then be examined by the dermatologist to determine if the hair has been shed and contains the hair bulb, or whether the hair has been broken and the bulb is not present. Counting the hairs can also help to determine if the amount shed is in excess of the normal 100-125 hairs.
Hair breakage is generally due to external factors, however abnormalities in hair shaft formation must be eliminated. Table 1 contains the technical terms used to describe hair shaft abnormalities and a definition of the term. Trichoschisis, trichorrhexis invaginata, pili torti, and monilethrix are all abnormalities intrinsic to the hair shaft. Trichoptilosis and trichonodosis may be due to cosmetic manipulation of the hair. Trichorrhexis nodosa may be due to intrinsic abnormalities or cosmetic manipulation. All of these conditions predispose the hair to breakage, which can become magnified by extensive grooming, chemical waving procedures, or permanent dyeing.
Hair breakage due to hair shaft abnormalities is rare, yet the dermatologist should be well versed in this area. The overwhelmingly most common cause of hair is hair breakage, which will be the focus of the remainder of this article. In order to determine the current status of the patient's hair several aspects of hair health should be observed. These include an assessment of hair shine, softness, and frizziness.
Hair shine is directly related to the condition of the cuticle. Hair possessing an intact cuticle with closely overlapping cuticular scales is shiny, healthy hair. It is the smoothness of the overlapping scales that promotes light reflection, interpreted by the eye as shine. Normal grooming processes such as combing and brushing result in loss of cuticular scales, which is more pronounced at the distal hair shaft. This process is known as “weathering” and is accelerated by overly aggressive grooming and chemical processing., The duller the hair appears, the more cuticle damage that is present.
Hair softness can be quickly assessed by the touching the hair shafts. Hair that is healthy is smooth and soft. Hair that has been damaged feels rough and harsh. Hair softness is also due to an intact cuticle, which creates a smooth hair shaft surface. Permanently waved or dyed hair must have a disrupted cuticle in order to allow penetration of the waving lotion or dye. Thus, chemically processed hair never feels as soft as virgin hair.
Frizzy hair is also indicative of cuticular damage. Hair that has been chemically processed is prone to static electricity. This is due to the charge that the hair shaft can maintain if the cuticle is missing. This allows the hair to repel one another and appear frizzy, especially at the distal shaft ends. Generally, chemicals applied to the hair penetrate better at the distal hair shaft due to less cuticlar scale. A well educated cosmetologist is aware of this fact, especially when processing long hair, and will apply the chemicals to the scalp first and then dilute the product prior to applying the solutions to the distal hair shafts.
The observational findings in a patient with hair breakage should be confirmed by microscopic examination of a shed hair shaft. The cuticular scales should be examined to note if weathering is present, confirming the gross observation that the hair is dull, harsh, and frizzy. Microscopic evaluation can also identify the extrinsic hair abnormalities. If the cuticular scales are greatly decreased at the distal hair shaft, trichoptilosis (split ends) results from exposure of the soft medulla. If trichonodosis is observed, hair twisting or teasing may be the cause of the knots predisposing the hair to breakage. If trichorrhexis nodosa is present, and not part of a genodermatosis, this suggests extensive cuticular loss. Once the cause of the hair breakage has been identified, it is then possible to recommend cosmetic techniques for minimizing hair loss.
Hair grooming includes cleansing, drying, combing, brushing and styling of the hair. While any manipulation of the hair shaft can cause breakage, loss can be minimized by recommending proper grooming, shampooing, conditioning, styling and cosmetic hair care practices to the patient.
Improper hair grooming practices are the most common cause of hair breakage. Since hair grooming occurs on a daily basis, simply changing how the hair is handled can decrease the amount of hair needlessly lost. Hair shafts are most subject to fracture when wet, since wet hair is more readily stretched to the breaking point. Therefore, hair should be initially detangled with the fingers and slightly dried prior to detangling with a wide toothed comb. Brushes are not appropriate for detangling, since they tend to tear and fracture the hair shaft. In general, all hair grooming should be kept to a minimum. The less the hair is manipulated, the less opportunity for hair breakage. The idea that 100 brush strokes a day is beneficial to the hair is mistaken.
The proper selection of grooming implements is also important. Combs are preferred over brushes, since there is less surface area to create friction and cause hair shaft fracture. Combs should be selected for their smooth widely spaced teeth allowing the comb to glide freely through the hair. Similarly, brushes should have widely spaced bristles with rounded tips. Whether the bristles are synthetic or natural is less important than the spacing of the bristles. Any grooming implement that feels rough when stroked across the palm of the hand is likely to tear the hair shafts and result in unnecessary breakage.
Many people feel that the hair must be shampooed daily for proper hygiene. Actually, shampoo is designed not to clean the hair, but to clean the scalp. Small amounts of sebum on the hair shaft are desirable for smoothing the cuticular scale and decreasing static electricity. This allows the hair to appear shiny and lay smoothly against the scalp. However, in persons with fine or thinning hair, the sebum decreases hair frizz making the hair appear less full. As contradictory as this may seem, these people who should ideally shampoo the least, shampoo the most. Cleansing the hair should be done only when required due to dirt in the hair or excess sebum. If sebum production is minimal and the patient has a sedentary lifestyle, daily washing is not necessary for good hygiene. The friction generated between the hair shafts while shampooing is an unavoidable cause of unnecessary hair loss.
The use of a conditioner after shampooing can be helpful in the patient who has excessive hair breakage and insists on continued frequent shampooing. An instant conditioner can be valuable in minimizing hair loss by detangling the hair and reducing friction between the comb and the hair shafts and between the individual hair shafts.
Basically, a conditioner functions like sebum to place a protective coating over the hair shaft, but conditioners are designed not to leave the hair with a greasy shine or lack of body. For patients who are having difficulty with hair breakage, the best hair conditioners are those that contain dimethicone (Pantene, Procter & Gamble). This agent does not decrease hair body, yet reduces hair shaft combing friction. The dimethicone is also beneficial for increasing hair shine, which is usually reduced in this population of patients.
Careful hair drying is important to prevent hair breakage, even though many patients ignore the problems that can arise from this frequent activity. The most common way to dry the hair is aggressive rubbing with a towel. This should be avoided at all cost. Rubbing the hair shafts together while wet generates tremendous friction and hair breakage is the result. The wet hair can be blotted dry, but should not be combed or manipulated until some initial drying has occurred.
It is best if the hair is allowed to dry without externally applied heat, however many patients wish to speed up the drying process or style their hair while drying. Heat damaged hair from improper dryer use appears frizzy and curly at the ends. This damaged hair is significantly weakened and will eventually break. Furthermore, the hair shafts can develop an abnormality known as “bubble hair.” Bubble hair results when liquid water within the hair shaft is rapidly heated and turns to steam. The steam then escapes from the hair shaft by popping off the cuticular scale and creating a "bubble" in the contour of the hair shaft. The bubble deformity actually creates a point weakness, which will eventually fracture. Heat damage during hair drying can be avoided by using the lowest heat setting and holding the nozzle at least six inches from the scalp. It is also useful to select a specially designed vented blow drying brush should to prevent high temperatures from heat buildup along the styling brush.
As mentioned previously, the best way to prevent hair damage is minimize hair styling. Quite simply, the less the hair is manipulated, the less opportunity for hair breakage. Hair styles that minimize hair breakage should be loose and not require excessive hair pins or combs. All hair pins should be rubber coated with smooth edges so that the hair is not broken as the clasp is closed. Unfortunately, the clasp must hold the hair tightly or it will not remain in place. Rubber bands should not be used in the hair as they are difficult to remove.
There are several common presentations of patients who are experiencing hair breakage due to hair styling. The first is the patient who wears her/his hair in a pony tail or braid and notes decreased hair growth. Examination of the hair shows hair shafts fractured at the same distance from the scalp. This is due to repeated breakage where the hair clasp is placed. A second presentation is the patient who wears braids on the scalp, also known as corn-rows, and notes thinning at the front hairline. In this instance, the hair is broken due to tension at the front hairline and traction alopecia may also be present. Basically, hair pulling should be avoided to minimize fracturing the weakened hair shaft.
Many patients with thinning hair elect to color their hair. While there is no hair coloring that does not weaken the hair shafts, there are some coloring methods that are less damaging. In general, darkening the natural hair color is less damaging than lightening the natural hair color. Lightening of the natural hair color requires a bleaching procedure followed by a dyeing procedure. This two step processing is more damaging than simply dyeing the hair, which is a one step procedure. Patients should be counseled to keep their hair color as close to their natural color as possible. More dramatic color changes will result in more hair shaft damage and further weakening precipitating hair breakage and loss.
Permanent waving of the hair is more damaging than dyeing since the protein structure of the hair shaft is actually degraded and reconstructed in a new form. Damage can be minimized by trying to achieve loose curls instead of tight curls. This is achieved by wrapping the hair loosely around larger curlers, which minimizes the number of disulfide bonds that are broken and reformed during the permanent waving procedure.
Hair shaft damage can also be minimized by shortening the processing time, which decreases the amount of disulfide bond breaking. The optimal processing time is determined by performing a "test curl". The test curl is one lock of hair wrapped around the curling rod, usually at the nape of neck. The hair is periodically unwound to determine if the desired amount of curl has been achieved. The test curl helps to prevent overprocessing of the hair by allowing neutralization of the permanent waving procedure when a slight amount of curling has been achieved.
Many patients both permanently dye and wave their hair. While the damage produced by these procedures is additive, it can be minimized by allowing ten days between procedures. It is also important to counsel patients that they should undergo the permanent waving procedure first, followed by hair coloring. Reversing the order of these procedures results in excessive hair cuticle damage and increasing hair shaft weakening.
Hair breakage is one of the most common forms of hair loss. It usually arises from aggressive grooming practices, intrinsic structural hair shaft abnormalities, or hair shaft weakening due to chemical processing. Years of hair grow can be removed from the scalp instantly by aggressive combing and brushing.
The recent sunscreen guidance issued by the US FDA commented on the fact that hair care products are not eligible for SPF values on the packaging. Certainly, hair is nonliving and as such cannot be sunburned or undergo photocarcinogensis; however, UV and visible radiation are very damaging to the cosmetic value of the hair. It is understandable why an SPF is difficult to assign to a hair care product, since shampoos and instant conditioners are rinsed from the hair following use leaving behind a film that is difficult to quantitate. Hair styling products that are left on the hair, such as hair sprays, styling gels, and hair serum, may also unevenly coat the hair shafts making assignment of an SPF under normal use conditions impractical.
Photoprotection of the hair is an important topic for consideration, especially in women who are complaining of hair breakage or unmanageable hair. UV and visible light are extremely damaging to the hair fiber with much of the current understanding of photodamage coming from research in the textile industry on wool. This article examines the effects of photoexposure on hair and how the dermatologist can aid patients in restoring cosmetic attractiveness to their hair.
Much of the understanding regarding hair and how it interacts with UV radiation and visible light has come from the textile industry. Natural fibers, such as wool, cotton, silk, and rayon, discolor when exposed to sunlight. White fabrics tend to take on a light brown/yellow color, a process known as photoyellowing. In natural human hair there are two pigments, eumelanin and pheomelanin, accounting for the brown and red hues seen in hair, respectively. There is another melanin, known as oxymelanin, found in unprocessed human hair that has been exposed to sunlight. Oxymelanin is an oxidative photodegradation product.
Lighter colored hair, such as blonde hair, is more susceptible to hair photodamage than deeply pigmented hair, such as brown hair. Black hair begins to lighten in color after 300 hours of exposure to simulated sunlight while blonde hair begins to yellow after 300 hours of exposure to simulated sunlight and begins to lighten when exposed to 300-1200 hours of simulated sunlight exposure. The hair color lightening or bleaching is primarily due to the effects of visible light. However, not only does the hair change color, but also it experiences a 200-300% increase in friction, indicating damage to the proteins in the cuticle.
The hair protein that is mainly damaged by sunlight is cystine, which is oxidized to cysteic acid. It is the sulfur-containing amino acids that are most sensitive to oxidative damage and of course it is the sulfur-containing amino acids that give the hair its structural strength. Other amino acids, such as tryptophan and tyrosine, are also degraded by light. After 150 hours of sun exposure, blonde hair shows a 25-30% decrease in tryptophan, 25% decrease in cystine, and 80% decrease in tyrosine. As oxidation occurs, there is a compensatory 80% increase in cysteic acid. These same changes are also seen in black hair, but at least 300 hours of sun exposure was required to produce the same oxidative damage.
Sunlight also decreases the tensile strength of the hair fiber. This means that when the hair is combed and stretched, it is more likely to break. This effect is magnified with age as the diameter of the hair shaft decreases in both men and women. The diameter of female hair shaft increases up to age 35 and then decreased gradually after age 40 with further decreases after menopause. In men, the diameter of the hair shaft decreases after puberty.
The natural photoprotection in hair is melanin, which also provides endogenous photoprotection in the skin. Melanin is broken down by visible and UV radiation in the hair shaft giving rise to a phenomenon known as photobleaching. This phenomenon is especially pronounced in blonde hair, which lightens dramatically in the summer, but also results in permanent changes in the hair shaft internal amino acids and external lipids.
Unpigmented hair, such as gray and white hair, is more susceptible to UV damage than pigmented hair. Also, the rate of cystine disulfide bond breakage is greater for unpigmented than pigmented hair. This means that one of the best sources of photoprotection is hair dye.
White unpigmented hair looses more mechanical strength after 4 days of UV radiation than semipermanently dyed brown hair. This same effect is also present with permanent hair dyes. The permanent hair dye acts as a passive photofilter reducing the hair fiber protein damage by attenuating the incident light. The dye molecule absorbs the light energy, which promotes it to a more excited stated, followed by a return to ground state via radiative and nonradiative pathways. As might be expected, the darker the hair color the more photoprotection imparted by the dye.
While sunscreens to promote hair health with SPF ratings will not be forthcoming in the near future due to the sunscreen guidance, photoprotection of the hair shafts for cosmetic reasons remains important. It is worthwhile examining the skin of patients concerned about hair appearance for tanning. Usually tanned skin also means, “tanned hair.” Women in search of answers for excessive hair breakage and frizzy “unhealthy” hair may need to learn that photoexposure is as bad for the hair as it is for the skin. This may be a reason to encourage safe sun habits. Wearing a hat is good advice for both beautiful skin and beautiful hair!
A current trend in skin care that has arisen out of consumer belt tightening following the recession is the all-in-one skin care product. These are skin care products designed to have multiple functions. For example, the make up remover that also cleanses and moisturizes the skin. The sunscreen that moisturizes and reduces the appearance of facial wrinkles. The cleanser that also minimizes the appearance of pores. The hair shampoo that conditions and strengths hair shafts. The nail polish that builds stronger nails. Why have these complex claims become popular? Perhaps the consumer feels that money spent on a product that does a lot is well spent. Since it is hard to come up with new product terminology given the restrictions on cosmetic claims, perhaps marketing feels that a product with multiple uses is new and more appealing.
Whatever the reason for these new all encompassing skin care products, dermatologists need to carefully examine this trend to determine if these products are appropriate for patients with various skin conditions. For example, should an atopic patient use a cleanser that moisturizes for better results, since the drying effects of soap can exacerbate the condition? Should a patient with androgenetic alopecia use a cleansing, conditioning, and strengthening hair shampoo to minimize further loss from breakage? Finally, should a mature patient use a moisturizer that modulates the skin barrier to reduce the appearance of wrinkles? This article examines each of these scenarios to better understand the pluses of minuses of all-in-one products.
Should an atopic patient use a cleanser that moisturizes for better results, since the drying effects of soap can exacerbate the condition?
Skin cleansing is the most basic hygiene need that can exacerbate disease in patients with atopic dermatitis. There are a wide variety of cleansers in the marketplace that fall into several discrete categories based on the sebum and dirt removal needs of the patient. There are true soaps, which are alkaline products at a pH of about 9, that are excellent at removing sebum, but may cause dryness in atopics. There are also synthetic detergents, such as sodium cocoyl isethionate, the main surfactant in bar cleansers designed for sensitive skin, however, these products can only cleanse, since they are solid one-phase formulations. Basically, bar cleansers are designed to remove sebum and environmental dirt from the skin surface, which they do quite well, but the surfactant must rinse completely from the skin surface or irritation will result.
Bar cleansers still represent the most basic form of skin cleansing, but are slowly being replaced by liquid cleansers, which are emulsions, known as body washes. A body wash refers to a two-phase liquid with a hydrophobic phase and a hydrophilic phase that are held together by an emulsifier. The surfactant cleanser is in the hydrophilic phase and binds to the dirt, which is washed down the drain. Vegetable oils, humectants, dimethicone, and petrolatum are in the hydrophobic phase, which bind to the skin surface decreasing transepidermal water loss and providing an environment optimal for barrier repair. This is the mechanism of action for all-in-one products that claim to both cleanse and moisturize. These products are of use in atopic patients who either wish to bathe more frequently or those with severe disease.
The key question is: How does the cleanser know whether to cleanse away sebum or deposit the moisturizer? This is accomplished by varying the water concentration between the two skin care events, one being cleansing and the other being moisturizing. During the first phase of washing, the body wash is placed on a puff, to increase the amount of air and water in the emulsion, followed by rubbing it over the body. At this time, the concentration of water is very low, the concentration of body wash is very high, and cleansing occurs. During the rinse phase, the water concentration is very high and the body wash concentration is very low. It is during the rinse phase when the moisturizing ingredients are deposited on the skin surface.
The next question is: How does the body wash know how much of the moisturizing ingredients to leave behind? It is possible to construct the emulsion such that the moisturizer amount is very carefully controlled. Large moisturizing ingredient droplets within the emulsion, containing petrolatum, soybean oil, and dimethicone, create a high depositing body wash. During the rinse phase, these droplets are left behind on the skin surface. A product for normal skin might be a medium depositing product with smaller droplets leaving behind a lesser amount of moisturizing ingredients. The dry skin body washes are most appropriate for atopic patients because of the larger amount of leave behind skin protectant ingredients.
It is possible to measure the efficacy of body wash products by examining transepidermal water loss (TEWL) measurements in patients with atopic dermatitis. TEWL measurements are made with an evaporimeter, which consists of two humidity meters placed at a known distance from the skin surface. The distance between the two humidity meters is also known, as well as how much water vapor is going into the probe, allowing the calculation of water loss from the skin surface in terms of grams of water loss per meter squared per hour. This water vapor loss is an indirect measurement of the degree of barrier damage, which directly correlates with the skin injury caused by cleansing. Patients with atopic dermatitis have an increased TEWL based on their disease and defective barrier function. Some dermatologists, especially those in Europe, are beginning to use TEWL measurements as a method of meeting quality of care requirements for treatment of their atopic patients.
Liquid cleansers that both cleanse and moisturize are a consideration in atopic patients. Use of such a product may allow more frequent bathing or possibly prolong remission intervals. In this case, moisturizing cleansers are a reality and an important all-in-one product.
Should a patient with androgenetic alopecia use a cleansing, conditioning, and strengthening hair shampoo to minimize further loss from breakage?
Hair shampoos that contain conditioners work in the same way as the body washes previously discussed. As a matter of fact, the whole idea of a moisturizing cleanser came from the hair care industry concept of a conditioning shampoo. A conditioning hair shampoo cleanses during the wash phase when concentration of water is low, and conditions during the rinse phase when the concentration of water is high. Thus, breaking the emulsion with water and air contact allows conditioning to occur during the rinse phase and the cleansing to occur during the application phase of the shampoo.
Conditioning shampoos do not clean as well as a regular shampoo and do not condition as well as a plain conditioner, but they are of use in patients with androgenetic alopecia. These patients tend to have fine, thin hair that appears fuller with frequent shampooing to remove sebum. Frequent shampooing can dry the hair making it appear frizzy and dull. Conditioning shampoos are a good choice in this population to prevent over drying the hair.
The next question is how conditioning shampoos improve hair strength? Hair strength is related to the protein and water content of the hair. Protein and disulfide bonds are the structural elements of the hair, but the elastic properties of the hair are due to water bonds. Hair is pulled, combed, brushed, snarled, clipped, and banded. Each of these activities requires flexible deformation of the hair to resist breakage. If the hair is devoid of water, breakage will occur with less force. Conditioning shampoo improve hair strength through several mechanisms. First, an oily coating is placed over the hair to reduce water loss. Second, the oily coating reduces friction, which decreases hair breakage from combing, brushing, and snarling. Third, many conditioning shampoos contain protein which can diffuse into the hair shaft in areas where the cuticle is missing. The protein only remains in the hair shaft temporarily, until the next shampooing, but its presence increases hair shaft strength.
Thus, protein containing conditioning shampoos that clean, condition, and strengthen are a reality. In the adrogenetic alopecia patient, they should be used in combination with an instant conditioner, applied and rinsed in the shower, followed by a leave-in condition that is not rinsed. The conditioning shampoo is a start, but additional conditioning products are also recommended.
The last all-in-one product concept to evaluate is the wrinkle reducing moisturizer. One of the more important new concepts in skin moisturization is modulation of the water channels within the skin. The water channels, known as aquaporins, are present in all living cells to control osmotic balance. Aquaporins were discovered in the kidneys many years ago, as aquaporin 1 is the abnormality that leads to diabetes insipidus. Aquaporin 3, however, is found in the skin. Aquaporins are formed from six trans-membrane alpha helixes in a right-handed bundle. This channel allows the transport of substances, of urea and glycerol, in addition to water. It is interesting that a mouse model, deficient in aquaporin 3, demonstrates decreased stratum corneum hydration and impaired barrier function very similar to those seen in human atopic dermatitis.
Glycerin, a humectant that attracts water, is also transported in aquaporin 3 channels. It been recognized for many years that glycerin possesses a skin reservoir effect. That means that a morning glycerin application can still be measured two or three days later, provided that it has been applied every day for two weeks or longer. It was previously thought that glycerin somehow intercalated itself between intracellular lipids and modulated skin water content. But it appears that glycerin may be transported through aquaporin 3 channels by a substance known as phospholipase D, which results in the production of phosphatidylglycerol. Phosphatidylglycerol is a lipid that signals enzymes of cell differentiation. What does this mean? This means that glycerin, when placed on the skin surface, functions not only as a humectant, but also as a modifier of cell differentiation. The fact that older cells are not as well differentiated as younger cells means that glycerin might have a more profound effect on aging of the skin than previously thought.
The ability of substances to increase the water content of the skin can be measured scientifically through a technique known as corneometry. Corneometry is performed with something know as a pin probe. The probe contains pins that transmit electricity to the skin and sense electrical conduction. However, in order to be conducted electricity needs a conductor. What is the conductor in the skin? Water. So more water in the skin, will conduct more electricity, the corneometry reading will be higher, and the skin is better hydrated. If, on the other hand, the skin is dehydrated with less water, less electricity will be conducted, and the corneometry reading will be lower indicating less well moisturized skin. It is through this indirect measurement of the electrical conductivity of water that skin hydration is assessed.
Since water transport into cells and cell differentiation are linked, it is quite possible that moisturizing ingredients, such as the commonly used humectant glycerin, may improve skin functioning and reduce the appearance of lines of dehydration in addition to enhancing moisturization.
All-in-one products for skin and hair care may have merit. Not only is it possible that purchasing one product instead of two may save money, but combination products may offer attributes useful in some dermatologic conditions. This article has examined the use of moisturizing body washes in atopic dermatitis patients, conditioning shampoos in adrogenetic alopecia patients, and antiaging moisturizers in persons with photoaging. Newer formulations, better ingredients, and more insight into skin functioning are contributing to this advanced technology.
Hair coloring has seen a definite revival with men and adolescents embracing the idea that altering the color of the scalp hair is desirable, fashionable, and worthwhile. Hair dyeing was originally introduced to modern society as a method of camouflaging gray hair. No more. Hair coloring is now a fashion trend, an artform, a manner of personal expression, and, in some cases, an antiestablishment statement. Where is hair coloring going in and what aspects of hair coloring are of dermatologic significance? I shall try to address these issues more fully in this article.
Even though henna and indigo have been used to color hair for over 3000 years, modern synthetic organic chemistry has made the 20th century the era of hair color. The whole hair coloring industry began when Hoffman in 1863 noticed that paraphylenediamine produced a brown-black coloration when oxidized. But, the transfer of knowledge was slow in the late 1800s and it was not until 1907 that Eugene Schueller marketed the first commercial brand of hair color in 1907. He was a chemist and the founder of L'Oreal, still a leader in hair coloring technology today. Originally, hair coloring was limited to the professional salon, but in 1950 the first home-use hair dye was introduced.
Several companies, besides L'Oreal have dominated the US hair coloring market: Clairol, founded in 1931, and Roux, also founded in 1931. Clairol was founded by Lawrence Gelb who purchased the original hair coloring formulas from Dr. Friedreich Klein, a German chemist, for $25,000. By 1938, the sales of Clairol hair color had reached $1 million. The first hair color introduced by Clairol was called "Instant Clairol" and was reformulated in 1950 as "Miss Clairol Haircolor Bath." Further advances were made possible by the development of seimpermanent dyes, dyes that washed out after 6-10 shampoos, and this resulted in the launch of "Clairol Loving Care." Just last year, Clairol was acquired by Procter & Gamble from Bristol-Myers Squibb, who held the company since 1959.
Many hair dyes have now entered the marketplace specifically for men. These dyes can be classified as those designed to cover gray (Just for Men, Combe International), those designed to add color highlights, and those for lightening the hair to a blonde or white color. The components of hair dyes for men and women are identical. For this reason, hair dyes will be discussed as a unisex product. Hair dyes can be divided into gradual dyes, temporary dyes, semipermanent dyes, demipermanent dyes, and permanent dyes. Each of these types will be briefly discussed in light of current trends for hair dyeing.
Gradual hair dyes, also known as metallic or progressive hair dyes, are most commonly use by men who do not desire a dramatic change in hair color, only darkening of their gray (Grecian Formula for Men, Combe International). They are also available in formulations for women, but cannot be combined with permanent wave procedures or other dyes, since irreversible hair shaft damage and weakening will occur. This type of dye changes the hair color from gray to yellow-brown to black over a period of weeks. There is no control over the final color of the hair, only the depth of color and lightening is not possible. These hair colorings employ water soluble metal salts which are deposited on the hair shaft in the form of oxides, suboxides and sulfides.
This type of hair coloring is not popular among adolescent males or females, since a dramatic color change cannot be effected. Also, most teens wish to lighten their hair color, which is not possible with gradual hair dyes.
Temporary hair coloring agents comprise only 3% of the hair coloring market and are removed in one shampooing. They are used to add a slight tint, brighten a natural shade or improve an existing dyed shade. Their particle size is too large to penetrate through the cuticle, accounting for their temporary nature. They do not damage the hair shaft and may be used by persons who are paraphenylenediamine allergic. These dyes are most popular among elderly women who wish to achieve platinum hair. This is accomplished by adding a bluish or purplish temporary rinse to the hair after shampooing to cover yellow hues in the hair created by small amounts of remaining eumelanin or pheomelanin.
Male and female adolescents may use temporary hair colorants to create blue, green, red, or purple hair for a weekend party. They can also be applied to selected areas of the scalp to create multicolored hair. These hair effects are created by temporary hair dye sprays, mousses, or gels. The newest trend has been to add glitter to the temporary hair dyes to create iridescent hair. This effect was popularized by the United States gymnasts in the recent summer Olympics. Hair glitter can contribute to scalp pruritus and cause corneal abrasion if accidentally introduced into the eye.
An understanding of temporary hair dyes is useful to the dermatologist, since these textile dyes do not further damage the hair shaft. Occasionally, a patient may present who is dismayed with the undesirable color of her hair following an unsuccessful dyeing procedure. Many of these patients are anxious to redye their hair to a different shade. Unfortunately, repeat dyeing procedures undertaken in a short period of time may result in even more unpredictable color outcomes and irreversibly damaged, weakened hair. Temporary hair colorings can be recommended to this distraught patient as a way of achieving a better hair color, while waiting for fading of the undesirable color and new growth.
Semipermanent hair coloring accounts for only 10% of the current hair care market. Table 1 lists the names of some of the currently marketed products as a reference for the dermatologist. These products can be purchased in drug stores and mass merchandisers (WalMart, Target, Kmart, etc.) and are not formulated for professional salon use. They are designed for use on natural, unbleached hair to cover gray, add highlights, or rid hair of unwanted tones.
Semipermanent dyes are retained in the hair shaft by weak polar and Van der Waals attractive forces, thus lasting through 6-10 shampooings. Usually, 10 to 12 dyes are mixed to obtain the desired shade. Semipermanent dyes produce tone-on-tone coloring rather than effecting drastic color changes, so their role is actually in toning rather than dyeing hair. The less color change required by the patient, the more satisfied he or she will be with the semipermanent dye result. Semipermanent dyes are best suited for patients with less than 30% gray hair who want to restore their natural color. This is done by selecting a dye color that is lighter than the natural hair color since the dye will penetrate both the gray and the nongray hairs, resulting in an increased darkening of the nongray hairs. It is not possible to lighten hair with semipermanent dyes, since they do not contain hydrogen peroxide, nor is it possible to darken hair more than three shades beyond the patient's natural hair color. Thus, in the cosmetic industry, semipermanent dyes are known as suitable only for staying "on shade."
A newer form of hair coloring that is longer lasting than semipermanent dyes, but still not permanent, is known as demipermanent hair coloring. Demipermanent dyes are replacing semipermanent dyes and are available in both home-use and professional salon use formulations. They are longer lasting, usually remaining through 10-12 shampooings, and have the advantage of longevity without sharp color contrast with new growth, a characteristic of permanent hair dyes.
These products are packaged for both men and women, with the newest introduction being the use of adolescent male models on some boxes. Demipermanent dyes do not lighten hair, but are used to primarily add red highlights to brunette hair. Most commonly they are used to give the hair a burgundy hue, not attainable naturally due to the presence of only eumelanins and pheomelanins with brown and yellow colors. Burgundy hair requires the additional introduction of blue pigments into the hair shaft.
Demipermanent dyes are not as damaging to the hair shaft as permanent hair dyes, but may contain paraphylenediamine and thus may possibly cause allergic contact dermatitis in sensitized individuals.
Permanent hair coloring accounts for three of every four dollars spent on hair dyeing in the United States. They account for 85% of the hair dyes sold and are available in both home use and professional salon types. Their popularity is due to tremendous color variety, most product lines contain 20 shades, and the ability to both lighten and darken hair. Permanent dyes have been embraced by mature men and women to cover gray and by adolescent boys and girls to lighten hair. The main disadvantage of permanent hair dyeing used to be presence of roots, new hair growth of the natural hair color, but the presence of multicolored hair has become fashionable eliminating this problem. The Clairol advertising campaign of the 1960s that asked "Does she or doesn't she?" challenged others to determine if the woman was a hair dye user. Now, adults and adolescent males and females seem proud to sport locks of a new color every other week. The use of permanent hair dyes is no longer a well kept secret.
Permanent hair coloring is so named because the dyestuff penetrates the hair shaft to the cortex and forms large color molecules that cannot be removed by shampooing. This type of hair coloring does not contain dyes, but rather colorless dye precursors that chemically react with hydrogen peroxide inside the hair shaft to produce colored molecules. The process entails the use of primary intermediates (p-phenylenediames, p-toluenediamine, p-aminophenols) which undergo oxidation with hydrogen peroxide. These reactive intermediates are then exposed to couplers (resorcinol, 1-naphthol, m-aminophenol, etc.) to result in a wide variety of indo dyes. These indo dyes can produce shades from blonde to brown to black with highlights of gold to red to orange. Variations in the concentration of hydrogen peroxide and the chemicals selected for the primary intermediates and couplers produce this color selection. Red is produced by using nitroparaphenylenediamine alone or in combination with mixtures of para-aminophenol with metaphenylenediamine, alphanaphthol or 1,5-dihydroxynaphthalene. Yellow is produced by mixtures of orthoaminophenol, orthophenylenediamine and nitro-orthophenylenediamine. Blue has no single oxidation dye intermediate and is produced by combinations of paraphenylenediamine, phenylenediamine, methyltoluylenediamine or 2,4 diaminoanisol.
Permanent dyeing allows shades to be obtained both lighter and darker that the patient's original hair color. Higher concentrations of hydrogen peroxide can bleach melanin thus the oxidizing step functions both in color production and bleaching. Due to the use of hydrogen peroxide in the formation of the new color molecules, hair dyes must be adjusted so that hair lightening is not produced with routine dyeing. However, hydrogen peroxide cannot remove sufficient melanin alone to lighten dark brown or black hair to blonde hair. Boosters, such as ammonium persulfate or potassium sulfate, must be added to achieve great degrees of color lightening. The boosters must be left in contact with the hair for one to two hours for an optimal result. Nevertheless, individuals with dark hair who choose to dye their hair a light blonde color will notice the appearance of reddish hues with time. This is due to the inability of the peroxide/booster system to completely remove reddish pheomelanin pigments, which are more resistant to removal than brownish eumelanin pigments.
dye precursors in an alkaline soap or synthetic detergent base and the other contains a stabilized solution of hydrogen peroxide. The two bottles are mixed immediately prior to use and applied to the hair. The dye precursors and hydrogen peroxide diffuse into the hair where the new color is created. These new color molecules can also diffuse out of the hair shaft, accounting for some drift in color with time. Generally, as mentioned previously, the hair tends to drift toward red hues and looses the depth of color with repeat shampooing. This "brassiness" used to be considered undesirable, yet adolescents now intentionally attempt to dye their brown hair blonde to create these unusual red tones.
A relatively new trend in permanent hair dyeing is the technique of highlighting, also known as hair foiling. This technique involves the application of permanent hair dye to selected locks of hair that are then wrapped in the aluminum foil sheets used to cover oven baked potatoes. The foil keeps the hair dye from touching surrounding hair and preferentially dyes only the intended locks. Hairdressers may foil one lock of hair red, another lock of hair light brown, and another lock of hair blonde to create dramatic color variation. If large clumps of hair are dyed different colors, the effect looks quite artificial, however, if small clumps of hair are dyed different colors the variation creates a more cosmetically pleasing appearance. Sometimes artificially dyed hair appears flat and lusterless due to uniformity of color between the hair shafts. It is the natural variation in hair shaft color that gives natural hair some of its luster and shine. Foiling can be used to artificially create this effect.
Selective dyeing techniques are also becoming popular among mature men and women. It is normal for the hair of the side burns and temple to gray before the top of the scalp in men and women. In order to minimize the amount of gray hair, while preserving some of the natural gray color, hair coloring artists are selectively dyeing the hair on the top of the head with minimal or no dye application to the temples. Sometimes blonde highlights are added around the face only to give the "sun-kissed" look, which naturally results from UV-induced hair bleaching. These techniques of hair painting have become so artistic that many salons offer hair color services only and do not cut or style hair. A popular hair colorist can charge $200-$300 for this artist type of hair blending.
This new type of permanent hair dyeing through selective hair shaft bleaching is of concern to the dermatologist, since these selected bleached hair shafts are more susceptible to breakage. Bleaching is uniformly a more damaging hair procedure than dyeing the hair darker or simply staying on shade. Over time, the hair shafts that have been lightened will break and patients may comment that their hair no longer is "taking" hair dye properly. Patients who care for their hair poorly and perform extensive hair bleaching also sometimes present with concerns that their hair is not growing or their hair is thinning. It is important to assess hair loss in the context of any chemical processing. The lists of at home and salon hair dye products should help the dermatologist determine the type of hair dye the patient is using and the relative risk of hair damage.
The widespread use of hair dyes by women, men, and adolescents has led to concern over the safety of hair dyeing. The allergic potential of the paraphenylenediamine component of hair dyes is well known to the dermatologist. Paraphenylenediamine is a familiar ingredient on standardized patch test trays and the TRUE test patches. Most dermatologists will encounter at least one case of paraphenylenediamine allergic contact dermatitis over a lifetime of practice. The allergy is characterized by scalp pruritus and erythema, when the reaction is mild, and facial edema including eye swelling, when the allergy is severe. All hair dye products recommend applying a small of the dye to the skin of the neck as a test prior to hair dyeing to rule out the possibility of allergic contact dermatitis.
Another concern with the use of hair dye is carcinogenicity of the aromatic amines that are used in hair dyes. These substances were found to cause tumors in rodents fed the maximum tolerated dose at the National Cancer Institute (NCI). Similar results were found in the Ames test. Modern hair dyes now undergo extensive toxicologic testing and are felt to be safe due to elimination of the questionable ingredients.
The next frontier in hair color will be the prevention of gray hair through melanocyte stimulating factors and the natural alteration of hair color through the use of melanin modulators. This technology is currently at the petri dish stage. Ongoing cooperative research between my laboratory and others has been slowed by the need to develop stable melanocyte cultures from the hair bulb to test chemicals designed to alter the production of eumelanin and pheomelanin. The fragility of hair melanocyte cultures has slowed the research, but several commonly encountered safe substances show great promise. Other research is focusing on techniques of removing toxic oxidative melanin byproducts from the follicular melanocytes, which theoretically may allow remelanization to occur. For the time being, however, we shall have to be content with dyes that create color changes synthetically.
Hair styles are in part dictated by the technology available in hair conditioning and styling products. The invention of hair gel virtually introduced a whole era of male fashion in the 1950s marked by slicked back stiff hair. This characteristic male hair style reminiscent of the movies "Grease" and "American Grafitti" would not have been possible without the discovery of hair gelling agents that made the hair stiff and shiny. A similar memorable era in female hair styles was the 1960s characterized by the bouffant beehive. This architectural hair wonder was made possible by the development of aerosol hair sprays based on newly discovered varnishes.
The current hair styles of the millenium focus on the "bed head" look and the attainment of perfectly "spiked" hair. Formable hair waxes made possible through the development of polymers that soften at body temperature such that they can be reformed, yet provide a soft hold in the desired position, are responsible for creating the "just got out of bed look." The short "spiked" hair popular among teen boys is created by an updated high hold version of the 1950s hair gel. All of this has been made possible by the ingenuity of the cosmetic chemist and hair dressers.
This article will cover the various categories of hair conditioners that can be labeled as instant conditioners, deep conditioners, leave-in conditioners, and hair rinses.
Many of the currently popular hair styles require frequent shampooing. This is necessary since the styling gels, mousses, and sprays are not reformable. This means that once the hair has been fixed in a given position it cannot be combed or brushed. In order to properly groom the hair, the styling product must be removed via shampooing. Some high hold styling products require the use of a detergent shampoo to remove the polymer and prevent styling product build-up. Thus, the hair must be shampooed daily with a strong cleaning shampoo that can leave the hair unmanageable. In order to restore manageability, an instant conditioner must be used. Instant conditioners must also be used by persons who have hair damaged by permanent waving or dyeing.
Instant conditioners are so named as they are applied following shampooing, left on the hair for five minutes, and subsequently rinsed. These products provide minimal conditioning due to their short contact time with the hair and are basically useful to aid in wet combing and manageability. Their ability to repair damaged hair is somewhat limited. Nevertheless, they are the most popular type of conditioner for both home and salon use. Instant conditioners contain water, conditioning agents, lipids and thickeners. The conditioning agents consist of combinations of cationic detergents, film formers, and proteins as discussed previously in Part I of this series.
The instant conditioners that are most relevant to the dermatologist are those that contain protein. Hydrolyzed protein fragments can enter the hair shaft and add strength to damaged brittle hair. The protein fragments diffuse in during the brief period the instant conditioner remains in contact with the hair shaft and then are removed during the subsequent shampooing. Thus, instant conditioners must be reapplied with each water contact. Protein-containing instant conditioners should be recommended to patients that are experiencing hair breakage resulting in hair loss. While the conditioner cannot grow hair, it can improve the appearance of existing hair, which is of value to any hair loss patient.
Deep conditioners are generally creams that remain on the hair for 20-30 minutes prior to shampoo removal. Instant conditioners are generally liquids that remain in contact with the hair for a few minutes, as discussed previously. Deep conditioners contain the same conditioning agents as instant conditioners, but are more concentrated. The goal of a deep conditioner is to allow the conditioning agent to more thoroughly coat and penetrate the hair shaft to improve its cosmetic appearance. Sometimes heat is used to enhance penetration in the form of a hair dryer or warm towel to cause hair shaft swelling, which allows increased conditioner penetration.
These products are intended for extremely dry and damaged hair. Many patients who present to the dermatologist complaining of hair loss are actually experiencing hair breakage and not true hair loss from the follicle. These patients have subjected their hair to too much manipulation, both chemical and physical, for the hair fiber to maintain its strength. Specialized deep conditioners, known as fillers, can be recommended to these patients to minimize the hair damage from additional chemical processing. Fillers are designed to condition the distal hair shaft and reverse some of the effects of hair damage, allowing even application of the subsequent coloring or waving procedure. The patient can request the use of such a product at the salon where she has her hair treated.
A new trend in deep hair conditioning is known as trichotherapy. This technique involves the application of essential herbal oils to the hair followed by massage. The oils are said to balance the scalp, relieve stress, and encourage hair growth. For example, peppermint oil is used to calm seborrheic dermatitis, lavender oil is used to stimulate hair growth, and tea tree oil is used to minimize scalp itching. These oils are usually left in contact with the scalp and hair for 30 minutes and can provide some moisturization, however their main benefit is aromatherapy, calming the senses through smell and touch.Some salons offer a deep conditioning treatment known as trichotherapy or aromatherapy. The value of this treatment is primarily esthetic.
Leave-in conditioners are applied following towel drying of the hair and designed to remain on the hair shaft to aid in styling. They are removed with the next shampooing. A large category of leave-in conditioners is known as blow drying lotions. These lotions are designed to coat the hair shaft and protect the protein from heat damage during the drying process. Other styling or sculpturing gels are designed to increase hair shine while stiffening the hair such that it will remain in the desired location. These products bridge the gap between hair conditioning and hair styling.
The most popular leave-in hair conditioners are used by persons with curly or kinky hair. These products lubricate and moisturize the hair shaft while aiding in styling. For example, oil sheen sprays and oily pomades help retain water within chemically straightened hair shafts and decrease the combing friction between hair shafts thereby preventing hair breakage. For persons with fine, straight hair, the oily leave-in conditioner would render the hair limp and hard to style, but for persons with coarse kinky hair, the oils improve manageability and impart shine. These products typically contain petrolatum, mineral oil, vegetable oils, and silicone. It is possible for the vegetable oils to produce pomade acne around the face. Persons who the dermatologist thinks might be experiencing pomade acne should consider using a glycerin-based pomade or leave-in conditioner.
Hair rinses fall under the category of hair conditioners. They are typically thin liquids applied like an instant hair conditioner. There are two types: clear rinses and cream rinses. Clear rinses, formed from lemon juice and vinegar, were used prior to the development of pH-balanced shampoos with sequestering agents designed to prevent soap scum formation on the hair. These acidic chemicals removed calcium and magnesium soap residue and returned the hair to a neutral pH following use of an alkaline shampoo. Residue removal restores hair shine while pH neutralization restores hair manageability. Clear rinses work well in patients with oily hair, but are not recommended for patients with normal to dry hair.
Cream rinses, on the other hand, utilize cationic quaternary ammonium compounds, such as stearalkonium chloride and benzalkonium chloride. Cream rinses are thinner than conditioners, but the differences in formulation are small. Some companies even label their products as “cream rinse/conditioners.” As a general rule, cream rinses provide less conditioning than conditioners and are intended for oily to normal hair.
Some conditioners do indeed incorporate sunscreens designed to add photoprotection to the hair shafts. While the hair is made up of nonliving material and cannot develop cancerous changes, its cosmetic value can be diminished through excessive exposure to the sun. Dryness, reduced strength, rough surface texture, loss of color, decreased luster, stiffness and brittleness of the hair are all precipitated by sun exposure.
Hair protein degradation is induced by light wavelengths from 254-400 nm. Chemically, these changes are thought to be due to ultraviolet light induced oxidation of the sulfur molecules within in the hair shaft. Oxidation of the amide carbon of polypeptide chains also occurs producing carbonyl groups in the hair shaft. This process has been studied extensively in wool where it is known as “photoyellowing.”,
Bleaching, or lightening of the hair color, is common both in brunette and blonde individuals who expose their hair to ultraviolet radiation. Brunette hair tends to develop reddish hues due to photooxidation of melanin pigments while blonde hair develops photoyellowing. The yellow discoloration is due to photodegradation of cystine, tyrosine, and tryptophan residues within the blonde hair shaft. Furthermore, hair treated with permanent or semipermanent hair dyes may also shift color when exposed to sunlight.
Sunscreen containing conditioners are available; however, there is some debate as to their effectiveness in protecting the hair and the scalp. In order to develop a standardized rating system for hair products, the concept of HPF, or hair protection factor, has been proposed. This is similar to the concept of SPF, or skin protection factor, except that tensile strength assessments of the hair shaft are used for grading instead of sunburn assessment. HPF ratings follow a logarithmic scale from 2 to 15. At present, shampoo formulations containing octyl-dimethyl PABA and hair spray formulations containing benzophenones have been proposed. Both of these products seem to decrease ultraviolet light induced melanin and keratin damage, thus preserving the color and structure of the hair shaft.
The adverse reactions associated with instant hair conditioners are remarkably small. This is due to the fact that hair conditioners are applied to the hair and rinsed quickly, allowing minimal time for any adverse reaction to occur. Rarely, hair conditioners can cause eye and skin irritation. If patch testing is required, these products can be patch tested “as is” in an open or closed manner.
The leave-in hair conditioners are a more frequent cause of irritant or allergic contact dermatitis due to their longer contact time with the skin. Leave-in hair conditioners that are based on film-forming polymers may be contaminated with monomeric impurities, such as acrylamide, ethyleneimine or acrylic acid. Acrylamide is highly toxic, ethyleneimine is carcinogenic, and acrylic acid is highly irritating to the skin. The safety and performance of polymers used in hair conditioners is related to their purity. Companies who market film-forming leave-in conditioners take great care to eliminate impurities in the polymer raw materials selected. I have never seen a polymer related problem from hair care products.
An understanding of hair conditioners is important to the dermatologist. Many patients who seek help regarding hair loss problems want something from the physician that will provide immediate improvement. Unfortunately, most of the currently available therapies, such as topical minoxidil, take time to work and may dry the hair further due to the medication vehicle effect on the hair shaft. Other medical causes of hair loss, such as pregnancy, iron deficiency anemia, and severe illness, take at least 6 months before new hair growth is recognizable by the patient. This means that hair conditioner recommendations offer an immediate improvement in hair appearance while supplementing other treatments instituted by the dermatologist.
One problem may be keeping current with the rapidly changing hair care market. All of the conditioners mentioned above are present within the Pantene hair care line (Procter & Gamble) and are distributed through drug stores, grocery stores, and mass merchandisers. I prefer these products due to their high quality, wide availability, and low cost, making them accessible to patients. However, the dermatologist may wish to try a variety of hair conditioners and determine which products are most efficacious. The hair conditioner market is highly competitive and personal preference for smell, look, and feel can be difficult to ascertain. Nevertheless, a brief discussion of hair conditioners should be part of any hair loss assessment.
Is it possible to increase the longevity of hair? Of course not. Hair is a nonliving tissue that cannot be altered once produced by the follicle. While this is true from a scientific standpoint, it is not true from a cosmetic perspective. Cosmetically, the longevity of hair is determined by how long it remains attached to the head. Thus, anything that causes hair breakage shortens the longevity of the hair shaft. Much industry research is directed at methods of decreasing hair breakage, which is the most common cause of hair loss. In dermatology, we tend to focus on follicular causes of hair loss, such as androgenetic alopecia, female pattern hair loss, alopecia areata, and telogen effluvium, to name some of the most common medically significant causes of hair loss. However, in the hair care industry, issues of grooming friction, cuticle condition, and weathering are evaluated as methods of increasing the longevity of hair.
This article deals with methods of increasing the length of time the hair remains attached to the head from a cosmetic perspective by evaluating 10 practical points to share with patients regarding decreased hair breakage. I have called these Zoe's Top 10 Hair Longevity Tips because no extensive studies have been done to document their scientific accuracy and they are based on my own practice experience. These are the ideas that I share with patients who complain of hair loss on their initial visit to the office, since sometimes I am not ready medically to render a concrete diagnosis until I receive laboratory results or have the patient bring in some lost hair for further analysis. I have found that offering these tips conveys to the patient that I understand hair loss, I am concerned about their problem, and I want to do something immediately to help them while waiting for additional information.
I have divided these suggestions into two parts, those tips dealing with hair styling or drying and ideas regarding hair shampoo and conditioner use. This article will comprise part one, with part two debuting next month!
There is a misnomer amongst hair stylists that the more you do to the hair, the healthier it becomes. This is not true. There is no such thing as a "body restoring permanent wave" or a "strengthening hair dye." The more you dye or perm the hair, the weaker it becomes. The more you comb, brush, curl, twist, clip, tease, braid, etc. the hair, the more damage it incurs. This damage is permanent, since the hair is nonliving. Basically, any manipulation of the hair shaft results in the possibility of cuticular damage, which is known in the hair care industry as "weathering." Weathering is visible even on the healthiest head of hair as a tightly overlapped intact cuticle on the newly grown proximal hair shaft, with a disrupted, sometimes absent cuticle on the older distal hair shaft. Weathering is basically the sum of chemical and physical environmental insults on the hair shaft, which can be minimized through reduced manipulation.
One of the most common insults the hair receives on a daily basis is grooming. This grooming is usually done with a comb. Thus, it is important to select a comb that decreases hair breakage by minimizing the friction between the hair and the teeth of the comb. For this reason, a comb should have broadly spaced smooth teeth, preferably Teflon coated, to reduce combing friction. A comb that tends to grab the hair shafts as they pass through the tangled hair increases hair shaft fracture, usually at the point where cuticular scale is most disrupted or completely absent.
Combing friction is also maximal when the hair shafts are tangled. Unfortunately, the most common reason for combing the hair is to remove tangles. This means that the hair should protected from situations that might cause hair tangles, such as wind, unconscious hair twisting, or teasing. The most effective way to reduce hair combing friction, besides proper comb selection, is application of a conditioner, a topic discussed later in this article.
The second most commonly used grooming implement is a brush and it too requires careful selection. The main goal again is to reduce friction between the brush and the hair shafts. Natural bristle brushes or brushes with a dense arrangement of bristles have recently become popular since they fit quite nicely with the current "back to nature" trend and the use of botanicals in the hair care industry, however these brushes maximize hair breakage. A better option is to select a brush design, known as a blow drying brush, for general grooming needs. These brushes possess vents or openings on the brush head to prevent heat from building up between the hair and the brush head. The widely spaced bristles are also plastic and ball tipped to minimize friction. If drawing the brush across the palm of the hand causes discomfort, the brush is not recommended for use on the hair.
Hair is much more likely to fracture wet than dry. For this reason, it is advisable to gentle detangle hair following shampooing from the distal ends to the proximal ends with the fingers, not attempting combing or brushing until the hair is almost dry. Many persons feel that the hair must be styled wet in order to attain the desired style. This is only partially true. Hair will set in the position in which it is placed the instant that the last water molecule evaporates from the hair shaft. This means that the hair is optimally styled just before it is completely dry. Thus, it is best to finger detangle the hair wet and then allow it to almost dry prior to styling to prevent hair breakage.
Many people prefer to speed the drying process by applying heat to the hair shaft to speed the evaporation of water. This can be done with a hand held blow dryer or a hooded professional salon dryer. Heat is also used to style the hair shafts in the form of heated rollers or a curling iron. Unfortunately, any type of heat that is applied to the hair shafts can permanently damage to protein structure of the hair.
It is important to distinguish between the water that resides on the outside of the hair shaft when the hair is wet and the water that resides inside the hair shaft to act as a plasticizer. Hair dryers attempt to speed evaporation of the water on the outside of the hair shaft and heating styling appliances attempt to rearrange the water deformable bonds within the hair shaft. Remember that water is the plasticizer of all of the keratin-based structures of the body including the skin, hair, and nails. When the hair is rapidly exposed to high temperatures, the water within the shaft turns to steam and exits the hair shaft creating a loss of cuticular scale and a condition known as "bubble hair." Under scanning electronmicroscopy is actually possible to see the bubbles created by the energetic steam. Unfortunately, the condition is permanent and bubble hair results in a weakening of the hair shaft that contributes to breakage.
The dermatologist should be aware that many patients who present with hair loss may be experiencing hair breakage due to bubble hair. While it is not possible to see bubble hair under a light microscope, it is possible to have the patient collect 4 days worth of hair loss, by placing each day's loss in a separate bag. The dermatologist can examine these bags to determine the ratio of broken hairs without the hair bulb to shed telogen hairs containing the hair bulb. If the number of broken hairs exceeds 20%, the patient is experiencing hair breakage. At this point, the dermatologist should inquire as to the use of heated hair drying and styling appliances and make some recommendations, however, most patients will not discontinue the use of heat.
Even though all forms of heat are damaging to the hair shaft, it is possible to minimize damage by altering the abrupt manner in which the hair contacts heat. Bubble hair is more likely to occur if the room temperature hair shaft is abruptly exposed to high heat. If the hair exposure to the heat is gradual, the damaging effect is not as great. Thus, a gradual temperature increase is recommended. This means that hair dryers can be safely used if the nozzle blowing out hot air is held at least 12 inches from the hair, allowing the air to cool prior to touching the hair shaft. Hair dryers also should be started on low heat to initially warm the hair prior to drying at higher temperatures.
Heat hair rollers and curling irons can be used safely if allowed to cool prior to application to the hair. These thermostatically controlled devices tend to slightly overheat, which can induce bubble hair immediately on hair contact. Heated styling devices should be unplugged for 1-2 minutes prior to placing them in contact with the hair. If possible, the styling devices should be operated on a low, rather than high, temperature setting. If the device does not have multiple temperature settings, the temperature of the metal or plastic that contacts the hair can be lowered by placing it in a damp towel. Many patients prefer to use styling heated devices at a high temperature setting, since the high temperature results in the rearrangement of more water deformable bonds and a tighter, longer-lasting curl. Hair that has been heat damaged appears wavy and friable to the human eye.
Even though hair is a nonliving substance, its “longevity” can be increased by caring for the hair in an optimal fashion. Much of the product development regarding hair care has been the adaptation of textile processing techniques to the human hair fiber. When hair is thought of as a fabric, it is easy to understand how proper handling of the hair fiber and limited exposure to damaging chemicals and environmental variables can influence its cosmetic performance. This article has discusses some of the suggestions I give to patients who are experiencing hair loss either totally or partially related to hair breakage.
Many of the ideas used in hair care products originated as technology in the textile industry. There are two main factors that degrade the appearance of a woven fabric: sunlight and friction. Amazingly, these are the two same factors that decrease the cosmetic value of hair. Sunlight induces a change in natural fibers, known as photoyellowing, whereby white fabric becomes yellow with light exposure. This change can be seen in a 20 year old wedding dress where the once white garment is now a shade of light brownish yellow. It can also be appreciated in hair as the development of shades of orange in originally brown or blonde hair. Some women actually seek this "sun faded" look by using bleaches to remove the eumelanins from the hair shaft thus speeding photodegradation of the hair pigments. Unfortunately, there are few effective hair care products to protect the hair from sun damage.
A new trend in the hair care industry to prevent pigment fading in dyed hair is to include a sunscreen in the conditioning product designed to be used immediately after dyeing and once weekly thereafter. These products are intended to prolong the life of the hair dye and do so by protecting the cuticle and leaving behind a UVA sunscreen. Inclusion of this after dyeing conditioner allows the manufacturer to claim that the hair dye is longer lasting and gentler to the hair. However, protecting the hair with a hat or scarf is clearly more effective. Patients who complain of the inability of their hair to hold a dye should be encouraged to cover their head when outdoors.
The second major factor I mentioned that damages the hair fiber is friction. Friction is the most common cause of hair loss because it ultimately results in hair breakage. This friction can be created by drawing a comb or brush through the hair, rubbing the hair shafts together while scratching or towel drying the scalp, or allowing wind to blow through the hair. Methods of reducing hair fiber friction will be presented as the last 5 tips to increasing the longevity of the hair.
It is not usual for patients with seborrheic dermatitis to present with the complaint of hair loss. Medically, it difficult to reconcile how a fungal infection of the skin of the scalp could alter hair growth from the hair follicles located deep within the dermis and in the superficial subcutaneous tissue. The answer to hair loss in the seborrheic dermatitis patient lies in having the patient collect all hairs lost while shampooing or grooming over a 24-hour period in a bag. Examination of these hairs will reveal absence of the cuticle and hair shaft fracture. Remarkably, it is possible to remove the entire cuticle from the hair shaft with 1 hour of vigorous scratching. Most patients will not scratch their scalp continuously for 1 hour, but the effects of scratching are additive to the hair shaft. One hour can easily be accumulated if the patient scratches 10 minutes a day for 6 days. Usually patients are intending to scratch only the itching present on the scalp, but it is impossible to scratch the scalp without scratching the hair shafts, as well.
Thus, the solution to hair loss in the seborrheic dermatitis patient is to treat the underlying disease. Many times I will treat my patients complaining of hair loss aggressively for scalp puritus in addition to my standard hair loss work-up. Fingernail damage to the hair shaft will result in dull, unmanageable, broken hair that performs poorly. Stopping hair shaft damage from scalp itching is key to solving the cause of hair loss in some patients.
Unfortunately, many patients who present to the dermatologist have already severely damaged their hair and permanent restoration is not possible. Yet, it is important to counsel the patient on how to optimize the appearance of their damaged hair until new growth occurs and the damaging cosmetic procedure has been discontinued. One such method of minimizing hair damage is to select a conditioning shampoo. There is no doubt that sebum is the optimal hair conditioner and all synthetic conditioners are a poor substitute, however, patients do not like the greasy, flat appearance sebum imparts to the hair shaft. This led to the introduction of shampoos designed to remove sebum from the hair. Remember that the original intention of shampoo was to remove sebum, skin scale, environmental dirt, and apocrine and eccrine secretions from the scalp. Patients forget that shampoo is to cleanse the scalp and not the hair when they are in the shower.
The need to improve the hair while cleansing the scalp has led to the development of conditioning shampoos. The main ingredient in this technology is silicone, a light weight clear oil that can coat the hair shaft and smooth the disrupted cuticular scale. This technology was pioneered as part of the Pantene line of shampoos, still manufactured today. These shampoos were originally known as 2-in-1 shampoos, since they both cleansed the scalp and conditioned the hair. They are available for all types of hair including: dry, normal, oily, and chemically treated. Silicone is instrumental in these formulas since it can coat the hair shaft without leaving the greasy appearance of sebum. The silicone also significantly reduces the friction of combing and brushing minimizing hair breakage. Thus, patients with hair loss or chemically damaged hair may benefit from the use of a conditioning silicone-containing shampoo.
Silicone technology has also been applied to instant conditioners. Instant conditioners are products applied immediately following shampooing in the bath or shower. They are left on the scalp for a short period of time and then thoroughly rinsed from the hair, hence the name "instant" conditioner. Since these products do not contain a surfactant designed to remove oils from the scalp, they can focus on augmenting the effect of a previously applied conditioning shampoo. Instant hair conditioners usually incorporate cylomethicone, dimethicone, or amodimethicone as their active agent, in addition to quaternary ammonium compounds. Amodimethicone is a cyclic silicone that appears to have more substantivity for hair keratin. This means that it sticks to the cuticle better and resists water rinsing, thus providing longer lasting conditioning. Quaternary ammonium compounds, also known as quats, are excellent at decreasing static electricity, which produces unmanageable frizzy hair.
While these important ingredients function to smooth the loosened cuticular scale and increase hair shine, they also reduce friction. By doing so, it is easier to detangle freshly washed hair, thus reducing hair breakage during the hair drying process. Hair conditioners also decrease grooming friction between the comb and brush and the hair fibers. Hair conditioners also provide a protective coating over the hair shaft that can protect from heat damage, discussed more thoroughly in last month's column, and the effects of UV radiation.
In short, one of the best recommendations the dermatologist can provide to the patient who is experiencing hair loss is to use an instant conditioner following shampooing. Use of this product will prolong hair longevity, no matter what the underlying cause of hair loss may be. No fabrics are sold without a fabric finishing, which improves wear and imparts shine to the fabric. It is actually removal of the fabric finishing that takes a soft cotton t-shirt and changes it into a stiff faded rag with repeated visits to the wash machine. These same changes occur with hair. Restoring the softness of fabric by using a fabric softener in the wash machine or dryer is analogous to applying an instant conditioner to the hair.
Occasionally it is necessary to impart more conditioning benefits to the hair fiber than an instant conditioner can deliver. This is especially the case in hair that has underdone chemical processing, such as permanent dyeing, bleaching, permanent waving, or chemical straightening. These procedures all intentionally disrupt the cuticular scale in order to reach the cortex and medulla of the hair shaft to induce a change in color or configuration. Once the cuticle has been disrupted with chemical processing, it can never be fully restored. Thus, there is a trade off for the patient between the cosmetic value of chemically treating the hair shaft and its reduced ability to function optimally. Some of the damage can be minimized by using what is known as a deep conditioner.
Deep conditioners are applied to hair for 20-30 minutes outside the bath or shower. They can be used both at home or in a salon. There are basically two types of deep conditioners: oil treatments and protein packs. Oil treatments are usually used for kinky hair that has been straightened. The process of lye straightening hair results in a decreased hair water content, which reduces the hair shaft elasticity and predisposes to hair breakage. Apply a heavy oil to the hair shaft is much like moisturizing the skin in that it attempts to both smooth the cuticle and prevent further water loss from the hair shaft. In general, oil treatments are not used for straight hair, since the heavy oil leaves the hair limp and difficult to style.
Protein packs represent a second type of deep conditioner and can be used by all hair types. These conditioners are formulated as creams or lotions and are a variation on the instant conditioner, except that they remain on the hair longer prior to rinsing. Protein packs may contain silicones and quaternary ammonium compounds, as previously discussed, but they also contain some form of hydrolyzed protein. Usually, collagen from animal sources is used, but any hydrolyzed protein will do. The protein can diffuse into the hair shaft through the cuticular defects creating by the chemical treatment. The protein can impart some strength to the hair shaft and also smooth the cuticular scale more thoroughly than an instant conditioner.
For patients who have chemically processed hair, I recommend a deep conditioner once every 1-2 weeks in addition to an instant conditioner after shampooing.
Many patients who are losing their hair are reluctant to cut their hair. I believe that they feel they should hang onto all their hair in case no more grows. Unfortunately, hair that has been damaged by too much chemical processing and too little conditioner application cannot be restored. For these patients, the overall appearance of the hair can be improved simply by removing 1-2 inches from the distal hair shafts. This trims away the split ends and creates new hair ends that are less frizzy, more likely to maintain a curl, less subject to static electricity. Trimming also eliminates the irregularity of broken hairs that creates a thin appearance. In short, removal of the damaged hair can create the illusion of fuller, healthier hair. Of course, the newly exposed ends must receive proper care or they too will develop and unattractive cosmetic appearance with time.
There are many approaches to hair care. Unfortunately, patients commonly think that the more they do to their hair, the better it will perform. This is not true. The hair is healthiest immediately after it emerges from the follicle and all manipulations result in damage. Again, I refer to the concept that hair can viewed as a fabric. Think of the appearance of a new wool coat. The fabric is shiny and smooth. After wearing the coat for a year, the fabric over the elbows, a major point of friction, develops fuzz balls, looses its shine, and feels harsh. The best way to keep a wool jacket looking new is not to wear it! While no one would want to take their hair off and put it in the closet, maintaining the integrity of the cuticle and reducing friction are key to a healthy head of hair. There is no salon procedure that can restore damaged hair to its original healthy state. However, the use of hair conditioners can temporarily improve the appearance of the hair and extend its longevity.
Ever wondered why there are so many different shampoos, conditioners, and hair styling products? The answer is simple. All hair is not the same. It is not the same color. It is not the same shape. It is not the same age. As a matter of fact, there are more types of hair than Fitzpatrick skin types. Confused? Probably. Do not worry, even the consumer is confused about which bottle to buy for great looking hair. Fortunately, if the current purchase does not provide the desired result, it can be washed out tomorrow and another attempt made with another purchase to produce another result. This type of trial and error drives much of the hair care market, yet as dermatologists we must put some type of science to the field
In reality, some of the most accomplished scientists work in the hair care industry. Hair care product design is a fine art with many advances derived from textile manufacture. Why is there so much excellent research on hair care? Because this area of cosmetics is unregulated, since hair is nonliving there are few health issues providing for increased creativity and diverse technologies. If this were the case with skin care, there would be many more skin care products with enhanced efficacy. Changes that occur in the hair shaft with chemical exposure and age are much better understood than similar skin changes. This makes the study of hair care an interesting endeavor.
The goal of this article is to highlight the differences between various types of hair. These differences result from underlying unique hair physiology and translate into hair appearance and behavior when exposed to various chemicals. Understanding these differences is key to developing a rational approach to selecting appropriate hair care products.
There are three basic hair fiber shapes corresponding to the major ethniticies in the world. The fiber shape is determined in cross section by slicing the hair perpendicularly to the fiber. Hair that is perfectly straight has a round cross section. It is the symmetry of the round cross section in any plane that allows the hair to hang straight. Round cross section hair is characteristic of Asian hair. When the round cross section becomes oval, it looses its symmetry in all planes. This asymmetry leads to wavy hair with the degree of curl influenced by the shape of the ellipse. As the major axis of the ellipse becomes longer and longer, the hair becomes more and more tightly curled. This type of hair is characteristic of Caucasian hair. When the ellipse becomes dramatically flattened and highly assymetrical, the hair is tightly kinked, representative of African-American hair. Variation in the cross section of the hair shaft accounts for the appearance of the hair curls found around the globe.
Hair fiber shape determines it behavior and other interesting attributes. Analysis of these attributes allow a better understanding of the differences in grooming needs between the various hair types and facilitates development of hair care products and procedures that enhance the beauty and performance of the hair. While it can be argued that hair is not essential for life, it can be proven that patients spend more money on their hair than on sunscreen!
For the sake of discussion, we will generalize the appearance of hair into three ethnic types, even though there is much diversity in hair appearance. The three hair types that we will discuss are Asian, Caucasian, and African-American hair, which can be described as straight, wavy, and kinky. Asian hair grows the longest of any hair type and is used in the manufacture of human hair wigs for this reason. The round hair fiber does not easily tangle and possesses less combing friction resulting in less hair shaft breakage. Caucasian hair is intermediate with African-American kinky hair growing the shortest. The hair shafts grow at the same rate, but African-American hair demonstrates the highest combing friction and is most susceptible to breakage. It is this common breakage with grooming that accounts for the popularity of hair straightening in African-American individuals.
The diameter of the hair fiber also varies between ethnicities. African-American hair has the largest diameter followed by Caucasian hair and Asian hair is the finest. This may explain the coarseness of African-American hair. The large hair shaft and its kinky tendency increase problems with ingrown hairs leading to pseudofolliculitis barbae and acne nuchae keloidalis.
The most common cosmetic hair problem is hair breakage. Whether the patient is young or old, male or female, curly or straight haired, hair breakage is still the most common cause of hair loss. Hair breakage can also contribute to loss in patients with hair disease, such as alopecia areata, lichen planopilaris, and androgenetic alopecia. Asian hair is the strongest hair with a breaking force of 63 grams, again explaining why it is used in the wig industry. Caucasian hair is intermediate with a breaking force of 43 grams and African-American hair is the weakest with a breaking force of 33 grams. The breaking force is the amount of weight that can be applied to a single hair shaft before fracture.
Machines that measure hair breaking force are commonly used in the hair care industry. All chemical hair procedures, including dyeing, permanent waving, and straightening, weaken the hair shafts. This weakening can be measured by hair shaft fracture at a lower breaking force. This force is measured by hooking both ends of the hair up to a machine that puts a known pull on the hair shaft with increasing pull exerted until the hair breaks. Superior hair chemical procedures produce the desired cosmetic end result without weakening the hair shaft. This is impossible. Thus, a compromise much be achieved.
Dermatologists may have encountered patients who claim that their hair is falling out following a permanent wave or hair straightening procedure. The patient may perceive more hair on the comb or brush, but the hair is actually breaking off from chemical weakening rather than actual loss with the hair bulb intact. Hair that has been chemically weakened cannot be restored to its original strength. Hair care products are developed and tested to determine if they increase the breaking force of the hair. These are the products that are labeled for chemically damaged hair.
The behavior of hair strength is also altered by wetting and drying the hair shaft. Wet hair is easier to fracture than dry hair, which is why hair should not be vigorously groomed when wet. Wet hair is highly elastic and can be easily stretched beyond its breaking point. Also, notice that again the breaking strength of Caucasian hair is greater than African-American hair. Hair with a more regular cross section has a higher breaking strength. Further, Caucasian hair is more stretchy than African-American hair both wet and dry, based on the elongation at breaking point data. This easily explains why Caucasian hair grows to a longer length than African American hair and highlights the need for hair care products specifically design for each hair configuration.
Table 2 presents the comparative amino acid characteristics of Caucasian and African-American hair. Notice that there are subtle differences. This information also points to the uniqueness of each hair type. This observation has led hair care companies to design chemical procedures, shampoos, conditioners, and styling products for different hair types.
There are other differences between African-American hair and Caucasian hair worth mentioning. For example, African-American hair has fewer cuticle layers than Caucasian hair, 7 as compared to 12. Since the cuticle is the outer protective layer of the hair shaft, fewer cuticle layers means the hair is more subject to damage and more easily weakened by cuticle loss. This may also explain the fragility of African-American hair. African-American hair also has a lower water content making the hair less elastic and more prone to fracture.
Hair straightening is a common practice among African-American individuals with kinky hair. The hair can be straightened with heat or chemical techniques. Chemical techniques are more popular because the hair is permanent straightened, as opposed to heat straightening that temporarily rearranges the water deformable bonds in the hair shaft.
The first permament hair straighteners, also known as hair relaxers or perms, were developed around 1940 and consisted of sodium hydroxide or potassium hydroxide mixed into potato starch. Once the disulfide bonds were broken, the hair was pulled straight and the disulfide bonds reformed in their new configuration. The proper chemical name for hair straightening is lanthionization. Hair straightening is popular among individuals with wavy to kinky hair for many reasons.
Lanthionization is a chemical process whereby curly hair is straightened through the use of metal hydroxides, such as sodium, lithium, potassium, or guanidine hydroxide, to change about 35% of the cysteine contents of the hair to lanthionine along with minor hydrolysis of the peptide bonds. Hair straightening can be achieved with lye-based, lye-free, ammonium thioglycolate, or bisulfite creams. The lye-based and lye-free procedures are most popular and will be briefly discussed in this article.
Lye-based, or sodium hydroxide straighteners are alkaline creams with a pH of 13. Sodium hydroxide is caustic substance that can damage hair, produce scalp burns, and cause blindness if exposed to the eye. These products are generally restricted to professional or salon use and may contain up to 3.5% sodium hydroxide.
Lye relaxers are available in “base” and “no-base” forms. The "base" is usually petrolatum that is applied to the scalp and hairline prior to application of the sodium hydroxide. This prevents scalp irritation and burns. The “base” relaxers contain between 1.5% and 3.5% sodium hydroxide and therefore require that the scalp and hairline be coated with a petrolatum base prior to application. These higher concentration lye products are necessary for hard to straighten hair. “No-base” relaxers, on the other hand, contain 1.5% to 2.5% sodium hydroxide and only require base application to the hairline. They are more popular since it is time consuming for the beautician to apply the base to the scalp and most individuals are re-straightening hair that has already been chemically weakened.
Other strong alkali chemicals sometimes used in place of sodium hydroxide are guanidine hydroxide and lithium hydroxide, which are known as "no-lye" chemical hair straighteners. These relaxing kits contain 4% to 7% cream calcium hydroxide and liquid guanidine carbonate. The guanidine carbonate activator is then mixed into the calcium hydroxide cream to produce calcium carbonate and guanidine hydroxide, the active agent. These products do not require basing of either the scalp or the hairline.
As a dermatologist, the one question I fear most from a patient as I begin to leave the examination room is: "Oh, by the way, I am losing my hair. What do you think I should do?" This question is simple for the patient to ask, but extremely complex for the dermatologist to answer. How do you begin to evaluate the commonly perceived problem of hair loss after you have already spent the allotted office visit discussing and treating the patient's four other presenting problems? I think diagnosing and treating hair loss is a tremendous medical challenge.
It is estimated that a patient must loose approximately 50% of their hair before a casual observer, such as a physician, can visually document the loss. Thus, when the patient comes in and states that their hair is thinning, a scalp evaluation may fail to yield confirmation of the patient's concerns. This means that the dermatologist must use other examination methods to determine the degree of hair loss.
Dermatologists should be aware that the number of hair shafts required to achieve the look of a healthy head of hair varies by hair color. This is partly due to the differences in the diameter of the hair shaft for various hair colors. For example, it only takes 90,000 red hairs to create the appearance of a full head of hair due to the thicker hair shaft diameter. Conversely, it takes 140,000 blonde hairs to create the appearance of a full head of hair due to the thinner hair shaft diameter. This may partly explain why red heads seem to have more hair than blonde individuals.
The patient who presents with no obvious hair loss is difficult for the dermatologist to evaluate. For this reason, I typically ask these patients to collect four consecutive days of hair loss, each placed in a separate plastic bag. The hair should be brushed or combed over the sink and collected from both the sink and the grooming implement. Hairs should also be removed from the drain following shampooing. I ask the patient to write on the bag if the hair was shampooed on the collection day. This allows me to reschedule the patient to return for a more accurate evaluation at a time when the office visit has been allocated to specifically addressing the hair loss problem.
Hair pulls in the office can be misleading, especially if the patient has shampooed prior to being examined and has removed the loose or broken hairs. It may prove difficult to get an accurate estimate of the magnitude of the hair loss from the patient, since most are not aware that a normal individual may loose approximately100 hairs per day. If grooming of the hair is infrequent, shampooing may yield up to 200 lost hairs.
The most important step in evaluating the patient with diffuse nonscarring alopecia is to determine if the problem is hair breakage or hair loss. Generally, hair loss results in shedding of the complete hair shaft, including the hair bulb, while hair breakage yields a hair shaft devoid of the bulb. Hair breakage typically results from aggressive grooming practices or cosmetic chemical hair treatments that weaken the hair shaft. These broken hair shafts do not contain the bulb. Other causes of fragile hair shafts include hair shaft abnormalities, such as trichoschisis, trichorrhexis invaginata, pili torti, monilethrix and trichorrhexis nodosa, which are found sporadically or in association with genodermatoses. Table 2 summarizes the structural abnormalities of the hair shaft, distinguishing between those that are due to internal causes and those that are due to external grooming practices. Examination of several plucked hairs under the microscope will confirm the diagnosis.
Hair loss can be easily distinguished from hair breakage by performing 10 hair pulls over various areas of the scalp. The hair pull is performed by grasping the hair shaft close to the scalp with the fingers and firmly pulling over the length of the shaft. Removed hairs are examined for the presence and formation of the bulb. If more than six hairs are removed per pull, excessive hair loss is present. This procedure also provides an opportunity to evaluate the condition of the entire scalp to determine that no localized areas of total hair loss are present, allowing elimination of scalp conditions such as tinea capitas and alopecia areata.
Once it has been determined that the hair loss is indeed in excess of 100 hairs per day and that normally formed hairs are being shed diffusely from a nonscarred scalp with an intact bulb, anagen effluvium and telogen effluvium must be considered. Anagen effluvium is generally due to internally administered medications, such as chemotherapy agents, that act as cell poisons and disrupt the growing hair follicle. Telogen effluvium, on the other hand, is due to an increased number of hair follicles prematurely exiting the anagen phase or hair cycle synchronization. Premature anagen exit can be due to medications, such as coumarin or heparin, while hair cycle synchronization occurs during pregnancy and with oral contraceptive use.
The causes of diffuse, nonscarring telogen hair loss are summarized in Table 3. Most of these considerations can be eliminated by a review of systems and some basic laboratory work. Anemia, thyroid abnormalities and many illnesses can be evaluated by obtaining a complete blood count with differential, thyroid panel and chemistry panel to include liver function studies. If deemed clinically necessary, an antinuclear antibody (ANA) can also be obtained to rule out any collagen vascular diseases. A complete history can determine the nature of any severe physical or emotional stress and document the ingestion of prescription or over the counter medications or vitamin supplements.
Surgeries, febrile illnesses and severe emotional stresses must be evaluated by the dermatologist for the past six months. A 3-month delay may be present between the actual event and the patient’s onset of hair loss. Furthermore, there may be another 3-month delay prior to the return of noticeable hair regrowth. Thus, the total hair loss and regrowth cycle can last six months or possibly longer. Patient’s should be educated as to when reasonable regrowth can be expected. The diagnosis of stress induced hair loss certainly has to be a diagnosis of exclusion, since there are no tests to reliably evaluate stress. I also have not found antidepressants to be helpful in the treatment of stress induced hair loss.
My preferred treatment for stress induced hair loss is adoption of a regular exercise routine of at least 30 minutes daily. I generally prefer aerobic exercises that require repetitive movements, such as walking, running, swimming, or bicycling. I prefer these over meditation because the stress reduction is accompanied by improved athletic conditioning.
Hair loss due to rapid weigh loss is not uncommon. Many times patients embark on franchised diet programs administered under the direction of a physician with prescribed meals and dietary supplements. Sometimes patients are told that vitamin supplements purchased as part of the weight loss program are necessary to prevent hair loss associated with dieting. From a dermatologist's standpoint, however, the vitamins cannot prevent hair loss associated with rapid, significant weight loss.
Even worse than rapid weight loss, is rapid weight gain followed by rapid weight loss in a repetitive cycle, a phenomenon described by some as "yo-yo" dieting. These patients never seem to stabilize their weight long enough for hair growth to occur. Behind improper hair grooming practices, "yo-yo" dieting is one of the most common causes of hair loss in otherwise healthy young women.
Hormonal causes of hair loss deserve special attention in the female patient. Many women do not realize that hair loss can present postpartum or following discontinuation of oral contraceptives. It is important to remind the female patient that hair loss may be delayed by three months following a hormonal status change and another three to six months may be required for regrowth to be fully appreciated.
Menopausal women with decreased ovarian estrogen production may also experience diffuse hair thinning, generally more prominent over the top of the head with bitemporal recession. A thin strip of hair at the anterior hairline is usually spared. FSH (follicle-stimulating hormone) levels can be obtained to document the onset of menopause, although menopausal hair thinning may be present even though FSH levels are not low. Institution of estrogen replacement can prevent further loss, but has not been shown to promote regrowth. Other treatments such as topical minoxidil may be indicated.
Recently, many postmenopausal women have discontinued their estrogen replacement therapy based on medical research indicating that hormone replacement was not helpful in the prevention of coronary artery disease. While this may be the case, I have seen many women in my practice who are experiencing dramatic hair shedding following discontinuation of hormonal therapy. These women and their physicians are unhappy about returning to traditional estrogen therapy. In these patients, I have tried to become creative in my estrogen therapy by recommending the use of intravaginal estrogen creams or use of the estrogen patch. Lastly, some of these patients may be helped by the use of food supplements containing phytoestrogens, such as soy supplements, roasted soy nuts, tofu, or flax seeds.
Lastly, it is important to rule out any hormonal abnormalities in the female patient. Inquiring as to the regularity of menses and the presence of infertility problems can uncover ovarian hormonal failure or the presence of excess endogenous androgens. Questions should also be directed as to whether the patient is ingesting oral steroids with androgenic effects. If necessary, hormone levels such as a free testasterone and DHEA-S (dehydroepiandrosterone sulfate) can be drawn and an endocrinologic evaluation initiated. A more detailed discussion of hormonally induced hair loss is beyond the scope of this article.,
Why would anyone care about a bad hair day? It doesn’t influence our ability to think or speak or be productive in society. Yet, a bad hair day can lead to lowered self-esteem, decreased self-confidence, and a poor social performance. The bottom line is that hair is very important. Why? Perhaps it is because hair is one of the few physical features that we can easily modify to suit our tastes or perceived image of beauty. If your skin is dark, it is extremely challenging to make it lighter; however, if your hair is brunette, you can make it blonde in less than one hour. If you are tall, it is impossible to become short; however, if your hair is long, you can make it short in less than 5 minutes. If the fashionable look changes from large oval eyes to small almond eyes, you are powerless to achieve the fashionable change. However, you can make your brown hair fashionably red within 30 minutes, keep it for 2 weeks, and then go gothic black. Yes, hair is one of the few body structures that we can control. It is for this reason that hair cosmetics and hair adornments are very popular. They allow easy experimentation and immediate gratification to those in search of something new, different, unusual, attractive, or strange. This article examines new trends in hair cosmetics to include foiling, bonding, and tattooing. These hair and scalp modification techniques have been selected as they present problems that may contribute to dermatologic issues.
Hair dyeing can be an expensive proposition. The average hair cut and permanent coloring procedure costs around $80 nationally with specialty salons charging as much as $500 in big cities. Hair dyeing must be repeated every 6-8 weeks depending on the fastidiousness of the consumer and the rate of hair growth. As the new hair grows, the junction between the natural hair color proximally and the dyed hair distally becomes increasingly obvious. This new growth is known as “roots” in the salon industry. A technique developed to decrease the cosmetic unattractiveness of roots is known as foiling.
Foiling involves the use of 3-6 different dye colors that are systematically applied to different clumps of hair on the scalp. Typically, dissimilar colors are selected within a color group. For example, a reddish blonde, a red, and a red brunette are used to cover gray and compliment the patient’s underlying brown hair color. Selective clumps of hair 1-2 inches wide are selected for individual application of each of the different dyes.
The permanent hair dye is painted on locks of hair subsequently wrapped in aluminum foil sheets. The foil is folded into individual pouches that are left in place 30-40 minutes until the hair dye has processed. The foil keeps the dye from touching surrounding hair and preferentially dyes only the intended locks. If large clumps of hair are dyed different colors, the effect looks quite theatrical, however, if small clumps of hair are dyed different colors, the variation creates a cosmetically pleasing appearance diminishing the drab monotone appearance of chemically dyed hair. It is the variation in hair shaft color that provides luster and shine, which can be mimicked with foiling.
Foiling also minimizes the harsh line between the natural hair color and the monotone dye. The intended hair color variation is only enhanced as the new hair grows allowing perhaps 8-12 weeks between dyeing procedures saving time, money, and hair damage. Foiling may also create a more naturally appearing hair color variation in mature men and women. For example, it is normal for the hair of the side burns and temple to gray before the top of the scalp in men and women. In order to minimize the amount of gray hair, while preserving some of the natural gray color, hair coloring artists are selectively dyeing the hair on the top of the head with minimal or no dye application to the temples. Sometimes blonde highlights are added around the face to give the "sun-kissed" look, which naturally results from UV-induced hair bleaching.
Hair foiling has become a form of “hair art,” such that many salons specialize in this technique only and do not cut or style hair. Many younger individuals use hair foiling to create dramatic hair contrasts. For example, the top of the head is dyed blonde and the hair at the nape of the neck is dyed black. This look was popularized by many female music personalities. A more mainstream foil combination places a lighter color on the top of the head with the same color 2 shades darker on the hair below the ears.
From a dermatologic perspective, hair foiling can create some interesting hair loss conundrums. The typical presentation is a middle-aged female who states that her hair is falling out preferentially on the top of her head. On physical examination, indeed the hair on the nape of the neck, which is a darker color, is more abundant than the blonde hair on the top of the head. The patients states that she is naturally brunette and her mother experienced hair thinning about the same age and is now forced to wear a wig. Without further thought, the easiest and most likely diagnosis appears to be androgenetic alopecia. The patient is advised to use 2% minoxidil twice daily and return to the office after a 6 month trial.
The patient returns in 6 months and states that her hair loss is worse. Was the minoxidil ineffective or is the diagnosis wrong? In this case, the diagnosis was wrong. The naturally brunette patient applied large volumes of peroxide to the hair on the top of her head to achieve the fashionable look. This degree of hair lightening requires two chemical procedures, bleaching and dyeing, that can occur simultaneously in some of the professional hair dyes on the market. These two procedures significantly weaken the hair shaft by removing structural proteins. The addition of the propylene glycol based minoxidil vehicle further damaged the already weakened hair shafts precipitating additional hair loss through breakage. The hair at the sides of the scalp was only dyed and not bleached, since the patient remained close to her original color in these areas. Thus, the hair on top of scalp was lost through breakage while the hair at the sides of the scalp remained creating an unusual pattern of preferential hair breakage.
These novel methods of combination hair dyeing can create unusual patterns of hair loss. The astute dermatologist should examine hair color variation closely when assessing individuals who complain of hair loss. The solution may be to discontinue the dramatic lightening of the hair on the top of the head where hair loss preferentially occurs.
Another method of creating variation in hair color is through the attachment of different colors of synthetic hair to the natural hair shafts. This is a technique known as bonding. Bonding uses a hot glue gun to fuse individual synthetic hair fibers to the base of clumps of existing scalp hair. Only a few fibers can be attached at a time, due to the weight of the additions. This technique is used in both men and women to thicken the scalp and eyelash hair. The scalp hair bonds are intended to remain in place for eight weeks, however individuals with excessive sebum production may notice early loosening and loss of the added hair.
The most popular use of hair bonding is to create long lush eyelashes, sometimes known as “Oriental eyelashes.” Usually 2-3 synthetic eyelashes are bonded to one native eyelash. The bonded eyelashes are usually slightly longer, more tightly curled, and darker than the natural eyelashes. They are popular among mature women with graying and thinning eyelashes. The longer curlier eyelashes can also be used to allow the eyelash hairs to show under redundant upper eyelid skin that covers the natural shorter eyelashes.
The problem with the bonded eyelash and scalp hairs is also hair breakage. The weight of the synthetic hairs accompanied by the rigid glue makes the natural hairs prone to breakage at the attachment point. This causes shedding of the hair prosthesis and may prevent reapplication if the native hair is too short. Similar hair breakage can occur on the scalp. Traction alopecia is another consideration.
An increasingly popular method of camouflaging thinning scalp and eyebrow hair in women is tattooing. Broad lines of brown to brownish-black pigment are applied to the scalp or drawn amongst the eyebrow hairs. This permanent method of scalp skin coloring may be appealing to women in their 40-50s, but is not a good solution to camouflage lost scalp hair. The tattoo pigment is quite unsightly in women with white hair in their 70-80s. It is impossible to remove without damaging the remaining hair follicles.
Tattooing is also a poor camouflage technique for lost or graying eyebrows, since the shape of the eyebrow changes with advancing age. As subcutaneous fat is lost from the forehead, the eyebrows descend onto and below the superior orbital ridge. If the eyebrows have been tattooed, the resulting folded skin creates an unnatural appearance. It is key to remember that a tattoo must be considered permanent and should create a cosmetically acceptable appearance for the entire life of the patient. Too often patients do not anticipate or recognize the inevitable facial changes with aging and are dismayed at cosmetic corrections made 20 years previously.
Foiling, bonding, and tattooing are three cosmetic hair procedures gaining popularity. Each of them poses interesting dermatologic issues. This article has highlighted the cosmetic technique, anticipated results, and complications.
What is a hair conditioner? Why should anyone need to use a hair conditioner? Hair conditioners are an important product category, since there are almost as many conditioning products as shampoo products on the store shelf. This article discusses the formulation and function of hair conditioners.
The history of hair conditioners is actually quite interesting, since the need for this product category arose following developments in shampoo technology. Originally, bar soap was used to clean both the hair and the body. Most bar soaps possessed an alkaline pH, which swelled the hair shaft leaving it unattractive and unmanageable. In addition, most homes used well water for cleansing with a high mineral content. The combination of the bar soap and hard water yielded soap scum that accumulated on the tub and also on the hair. This soap scum left the hair harsh and dull adding an additional source of scalp irritation.
The widespread use of municipal water sources and the development of liquid synthetic detergents that were formulated at a neutral pH with sequestering agents revolutionized hair shampooing. Now the shampoos left the hair soft and manageable and could be used more frequently without an adverse cosmetic result. This led to the current practice of daily or every other day shampoooing that efficiently removed sebum from the hair shaft. Sebum is, of course, the ideal hair conditioner. Excessive removal of sebum creates the need for a synthetic sebum-like substance that can minimize static electricity, increase hair shine, improve hair manageability, and also aid in maintaining a hair style. Thus, conditioners attempt to supply hair with the positive attributes of sebum while avoiding the greasy appearance indicative of excessive sebum and dirty hair.
Conditioners are liquids, creams, pastes, or gels that mimic sebum in making the hair manageable, glossy, and soft. The role of conditioners goes beyond maintaining the appearance of healthy hair. Conditioners also attempt to recondition hair that has been damaged by chemical or mechanical trauma. Common sources of trauma include excessive brushing, hot blow-drying, permanent hair waves, hair straightening, hair bleaching, etc. Damage to the hair shaft can also occur through environmental factors such as exposure to sunlight, air pollution, wind, seawater, and chlorinated swimming pool water. This type of hair damage is technically known as “weathering.”
Obviously, since hair is nonliving tissue, any reconditioning that occurs is minimal and temporary until the next shampooing.
Hair conditioners were developed during the early 1930’s when self-emulsifying waxes became available. These waxes were combined with protein hydrolysates, polyunsaturates and silicones to give the hair improved feel and texture. Early sources of the proteins included gelatin, milk and eggs. Currently, the most common ingredient in hair conditioners is silicone. Silicone is a light-weight oil that can leave a thin film on the hair shaft without creating the appearance of dirty hair. The amount of silicone left behind on the hair shaft determines whether the product is designed for adding body to fine hair where minimal conditioning is desirable or straightening curly hair where maximal conditioning is desirable.
Healthy, undamaged hair is soft, resilient, and easy to disentangle. Unfortunately, the trauma caused by shampooing, drying, combing, brushing, styling, dyeing, and permanent waving damages the hair making it harsh, brittle, and difficult to disentangle. Hair conditioners are designed to reverse this hair damage by improving sheen, decreasing brittleness, decreasing porosity, increasing strength, and restoring degradation in the polypeptide chain.
Hair conditioners improve manageability by decreasing static electricity. Following combing or brushing, the hair shafts become negatively charged. These negatively charged shafts repel one another and prevent the hair from lying smoothly in a given style. Conditioners deposit positively charged ions on the hair shaft neutralizing the electrical charge.
Hair manageability is another key issue. Manageability refers to the ease with which the hair is combed and styled. The key factor in hair manageability is decreased friction between the hair shafts. Friction is minimized if the hair shafts have smooth even surfaces. This means that the cuticular scales must be present and organized in a tightly overlapping manner. Hair conditioners can reduce friction between hair shafts by as much as 50%. This reduction in friction also aids disentangling of the hair following shampooing leading to a subset of conditioners, known as cream rinses, designed to make hair easier to comb following shampooing. A special subset of these products are designed to aid in combing children's hair.
Most consumers equate shiny hair with healthy hair. Hair shine results from light reflected by individual hair shafts. The smoother the hair surface, the more light reflected. Conditioners increase hair gloss primarily by increasing adherence of the cuticular scale to the hair shaft.
Hair shine is also related to hair structure. Maximum shine is produced by large-diameter, elliptical hair shafts with a sizable medulla and intact, overlapping cuticular scales. Thus, hair conditioners can increase hair shine, but some of the high shine seen with straight hair over curly hair is due to the inherent hair structure. Overlapping of the cuticular scale also contributes to hair softness.
Split ends occur when the cuticle has been removed from the hair shaft and the soft keratin cortex and medulla are exposed to weathering and grooming trauma. The protein of these structures, unable to withstand the damage, splits or frays much like a damaged textile fiber. Conditioners temporarily reapproximate the frayed remnants of remaining medulla and cortex. This strengthens the hair shaft and prevents breakage of the distal ends.
To expand the sales of conditioners, manufacturers have developed formulations appropriate for all hair types. For example, persons with kinky, unruly hair prefer a heavy conditioner that thickly coats the hair shaft to provide additional weight. The conditioner allows the hair to lay in the desired style while appearing shiny. However, this type of conditioner would make fine hair appear greasy and limp. Fine hair is particularly prone to weathering and hair grooming damage. This is because there are more fine hair fibers per weight than coarse hair fibers making the net surface area of fine hair greater. Proportionally more irregular cuticle scales can develop and more of these fine hair fibers are subject to static electricity. Thus, there are special conditioner formulations designed to meet the grooming needs of fine straight hair, which are unique from the conditioning needs of curly coarse hair.
There are several different active agents that can be combined to achieve a hair conditioner unique for a given type of hair. These conditioners are typically applied in the bath immediately after shampooing and rinsed thoroughly prior to hair drying. They are known as instant conditioners, since they must work quickly in the short contact time prior to water rinsing, yet the effect on the hair shafts must be long-lasting until the subsequent shampooing.
The primary classes of hair conditioning agents are listed in Table 1. Of these, the quaternaries are the most frequently used. These chemical classes are discussed in greater detail in Table 2.
The cationic detergents, also known as quaternaries or quaternary ammonium compounds or quats, are the most popular conditioning agents found in both shampoos and hair conditioners. Their primary benefit comes from the positive charge they possess. Remember that hair that is susceptible to the effects of static electricity is negatively charged. The addition of the cationic quaternary conditioner neutralizes the anionic charge of the hair and improves manageability. It is the attraction of the positively charged conditioner to the negatively charged hair shaft that allows the hair care product to remain on the hair following water rinsing.
Quaternary conditioning agents are used in conditioning shampoos, also known as 2-in-1 shampoos, which clean the hair but also leave behind a thin film of conditioner to improve hair appearance. With repeated grooming and shampooing, the hair becomes weathered and the cuticular scale loosened. The same effect is seen in woven textiles, such as cotton or wool sweaters, where fuzz balls and pilling occurs around areas of high fabric friction, such as the elbows. These fuzz balls occur because the textile fibers have broken and rolled into a ball. The cuticular scales also fracture, break, and clump. This creates increased combing friction and dull appearing hair. Quaternary conditioners are excellent at increasing adherence of the cuticular scales to the hair shaft, which increases the light reflective abilities of the hair, adding shine and luster. These qualities make them an excellent conditioner choice for patients with permanently dyed or permanently waved hair where the cuticle has been disrupted as part of the chemical process.
Film-forming conditioners also coat the hair shaft, like the quaternaries, but are based on some of the new light-weight polymers used in hair sprays and styling products. Film-forming conditioners apply a thin layer of polymer, such as polyvinylpyrrolidone (PVP), over the hair shaft to fill in defects and create a smooth surface. This increases light reflection improving hair luster and shine. In addition, the polymer coating eliminates static electricity due to its cationic nature.
Many of the film-forming conditioners claim to thicken hair. While consumers may think this means that more hair is present on the scalp, in actuality this claim is substantiated by measuring the diameter of each hair shaft after it has been coated by the polymer film. Indeed the hair shafts have been thickened, but not in the manner the consumer hoped!
Film-formers are used in conditioners designed to straighten kinky or curly hair. They are also found in products to add manageability to coarse hair, however persons with fine hair will find that the polymer coating makes the hair shaft limp and decreases the ability of the hair to hold a style.
Protein-containing conditioners are the most interesting from a dermatologic standpoint. As hair weathers, it looses its strength due to removal of the cuticular scales and damage to the underlying cortex. This damage creates areas where the hair shaft contains holes. These holes create sites for deposition of protein from a conditioner. Protein-containing conditioners can actually penetrate and alter the damaged hair shaft by increasing its fracture strength by 10%. These proteins, derived from animal collagen, keratin, placenta, etc., are hydrolyzed to a particle size (molecular weight 1000 to 10,000), which are able to enter the hair shaft. The source of the protein is not as important as the protein particle size.
The ability of protein-containing conditioners to strengthen the hair shaft depends on contact time. The longer the protein conditioner is left in contact with the hair shaft, the more protein that will diffuse into the shaft. Thus, proteins are used in instant conditioners designed for short term in shower contact and longer term deep conditioners designed to remain in contact with the hair for 30 minutes prior to removal. The protein diffusion is reversible, however. This means that any exogenous protein present in the hair shaft will be removed at the time of shampooing necessitating reapplication of the protein-containing conditioner.
This article has dealt with some of the key issues surrounding the use of hair conditioners. It is interesting to note that the need to condition the hair has arisen out of the development of better shampoos and increased bathing frequency. Hair conditioners can be thought of much like fabric finishing. Textiles are treated following weaving with chemicals designed to impart softness and shine. The finishing is removed with washing, which explains why inexpensive cotton shirts go into the wash machine soft and pliable only to emerge rough and stiff as a board. Hair is nothing more than a textile affixed to the human body. If the dermatologist views hair conditioners from this standpoint, it is easy to understand their function and formulation.
Much of the understanding regarding hair and how it interacts with UV radiation has come from the textile industry. Natural fibers, such as wool, cotton, silk, and rayon, discolor when exposed to sunlight. White fabrics tend to take on a light brown/yellow color, a process known as photoyellowing. In natural human hair there are two pigments, eumelanin and pheomelanin, accounting for the brown and red hues seen in hair, respectively. There is another melanin, known as oxymelanin, found in unprocessed human hair that has been exposed to sunlight. Oxymelanin is an oxidative photodegradation product. How does the alteration or absence of hair pigments influence how UV radiation interacts with human hair fibers? Hair research has yielded some surprising results.
Hair is a complex nonliving structure with an outer cuticle that provides a hard protective barrier for the inner cortex. The cortex is composed of fibrillar proteins, which are responsible for the mechanical strength of the hair shaft. Melanin pigments are contained in the cortex embedded in an amorphous protein matrix. Sometimes the hair shaft may contain a medulla, but the function of this inner structure is largely unknown and found less frequently in mature hair shafts. Sunlight can damage both the strength of the hair shaft, by increasing the scission of the cystine disulfide bonds, and produce oxymelanin, as previously mentioned. The natural pigments actually prevent disulfide bond disruption, preserving the strength of the hair shaft, even though color change in the form of pigment lightening occurs. In other words, chemical alterations in the hair pigment function to protect the protein structural backbone of the hair.
The entry of pigment sunscreens in the US marketplace, however, has been greatly slowed. Much of the research regarding new sunscreen development has been halted by controversy over the new sunscreen monograph, which has tentatively been put on hold pending more understanding of UVA photoprotection. At present, the only recognized rating system for sunscreens is the SPF (sun protection factor), which evaluates the impact of UVB radiation on the skin. The recognition that UVA radiation is equally as important in carcinogenesis and even more important in aging has caused dermatologists and industry representatives to ask for approval of a UVA rating system. Several proposals have been made to the FDA, but no final decision has been forthcoming. The push to develop a system for UVA rating stems from research regarding new pigment actives that protect in this wavelength.
Pigments are agents used to impart color to fabrics, cosmetics, and hair dyes. Many of these pigments can absorb and/or reflect light based on their internal chemistry. The newest UVA actives, such as Tinosorb, that have entered the marketplace in South America and Latin America are pigment sunscreens. Consumer acceptance of these new sunscreens has been overwhelming. What role do pigments have in hair photoprotection?
Until recently, the main approach to hair photoprotection has been the use of traditional UVB sunscreen actives in formulations designed for hair use, such as instant conditioners, styling gels, and hair sprays. The main problem with this topical approach to hair photoprotection is the failure to create an even film protecting the entire surface area of every hair on the head and the inability of a sunscreen to adhere to the hair cuticle. Coating each an every hair shaft with an equal thickness of sun protection without making the hair appear limp or greasy is a challenge no hair care product has yet overcome. This dilemma has led researchers to question whether photoprotection could be imparted to the hair shaft through another means, perhaps through the internal structure of the hair shaft.
The natural color of the hair shaft results from a combination of the visible light absorption and scattering abilities of the pigment granules distributed within the cortex. However, sunlight contains both visible light and UV radiation. Exposure of the hair to sunlight leads to lightening of the hair color, known as bleaching, and ultimately damage to the fiber itself. The components of sunlight that are altered by UV radiation include the amino acids and lipids. Interestingly, it has been shown that unpigmented hair is much more susceptible to this UV induced damage than pigmented hair, meaning that the color granules are providing some protection from oxidative damage. Also, the rate of cystine disulfide bond breakage due to environmental exposure is greater for unpigmented than pigmented hair. What is the importance of this observation? This indicates that white hair and advanced gray hair are more susceptible to the damaged effects of UV radiation than youthful pigmented hair. The issue of photoprotection to maintain the cosmetic value of the hair becomes important with advancing age.
If natural pigments within the hair shaft provide photoprotection, it may be possible to preserve the hair cosmetic value with synthetic pigments deposited on the cuticle and within the cortex via hair dyes. There are two types of hair dyes that can artificially increase the hair shaft pigments: semipermanent and permanent hair dyes.
Semipermanent hair dyes are composed of a combination of dyes, such as nitrophenylenediamines, nitroaminophenols, and amionanthraquinones. These dyes are left on the hair 25 minutes and are used in combination to arrive at the final desired color. As might be imagined, there is some initial damage that occurs to the hair fibers upon dyeing, however, as the hair is exposed to longer periods of UV radiation, the initial damaging effect of the dyeing procedure is outweighed by antioxidant effect of the color deposited on and in the hair shaft. Thus, white hair that is undyed exhibits more mechanical strength damage from UV radiation than semipermanently dyed hair after 4 days of exposure. As might be imagined, the darker the hair dye color, the more photoprotection provided. The semipermanent hair colors are a mixture of dyes designed to create the desired final color. Usually, a mixture of reds and blues are used to create brown. It is interesting to note that the red pigments produce better photoprotection than the blue pigments. This is probably due to the red dyes absorbing the more energetic part of the UV spectrum than the blue dyes.
This same effect was also observed with permanent hair dyes. Permanent hair dyes penetrate more deeply into the hair shaft creating color as a result of an oxidation/reduction reaction. They too act as a photoprotectant, however the permanent hair dyes are more damaging due to the hydrogen peroxide and ammonia used to allow the chemicals to penetrate the hair shaft. More alkaline dyes that allow enhanced penetration also provide better photoprotection. The permanent hair dyes can act as passive photofilters reducing the hair fiber protein damage by attenuating the incident light. This is accomplished by the dye molecule absorbing the light energy, which promotes it to a more excited stated, followed by a return to ground state via radiative and nonradiative pathways.
New insights into semipermanent and permanent dyes as a means of hair photoprotection are intriguing. Many of the female patients who present to the dermatologist for suggestions regarding hair growth are mature with gray hair. The temptation is to bleach the hair, thus removing any remaining pigment granules to produce hair color lightening. Hair that is gray or bleached possesses fewer pigment granules than brown hair and is thus more susceptible to sunlight. Darker hair colors are more resistant to photodegradation. Thus, it may be beneficial to mature women who enjoy the outdoors to dye their hair a darker color to prevent hair shaft weakening from UVA exposure.
Dandruff is a perplexing problem because it is a somewhat nebulous condition that comes and goes, but is never completely gone. Is dandruff caused by one etiologic factor? Is dandruff a disease? What is the relationship between dandruff and seborrheic dermatitis? What can be done to prevent relapse? What constitutes maintenance therapy? These are all interesting questions that I shall attempt to answer in this article.
For a consumer, dandruff is a huge problem and from an industry standpoint, dandruff is a huge market. Just take a walk down the shampoo aisle and notice all of the dandruff shampoos. Most shampoo brands contain a bottle labeled for the treatment of dandruff. Even conditioners are now available specifically for dandruff sufferers and very effective post-shampoo treatment products are even available. There is no doubt that the dermatologist needs to be keenly aware of the over-the-counter market for these products.
Dandruff is basically the sloughing of desquamating corneocytes from the scalp. However, the presence of hair on the scalp makes this process more difficult. Since the corneocytes are pinned in place by the hair, physical removal of the skin scale via rubbing becomes more important. Thus, frequent shampooing is required to dislodge and remove the scale via water rinsing. Frequent combing or brushing only makes the condition worse because the scale is dislodged but not efficiently removed from the hair. Yet, this is not the whole story. If you examine the flakes of dander from patients with and without dandruff, there is a noticeable difference in the size of the flakes between the two patient groups. Patients with dandruff have much larger flakes indicating a different desquamatory process. This may be why keratolytics are one of the most important dandruff treatments.
In addition to desquamatory defects, there are other unique scalp attributes of patients with dandruff. A fungal culture of dandruff sufferers yields a higher than normal population of the fungus Malassezia globosa. Tom Dawson, PhD, at the hair research laboratories of Procter & Gamble, discovered this finding. He collected numerous specimens from thousands of patients with and without dandruff and concluded that this organism was the causative factor for dandruff. In the past, it had been thought that Malassezia furfur was the fungal cause, however this fungus has now been relegated to only causing tinea versicolor. Thus, eliminating the skin scale is in part related to the ability to reduce the Malassezia globosa scalp population.
Why do some people get only dandruff and others get full blown seborrheic dermatitis? I believe that dandruff and seborrheic dermatitis reside on a continuum with dandruff representing mild non-inflammatory disease and seborrheic dermatitis representing severe inflammatory disease. The difference between the two conditions resides in the patient response to free fatty acids. As the Malassezia globosa population increases on the scalp, it must have a ready nutritional source. Interestingly, Malssezia globosa eats scalp sebum removing nutrients necessary for growth and releasing free fatty acids as a by product. These free fatty acids are extremely irritating to the scalp of susceptible patients. Exactly why some patients react with strong itching and burning to the free fatty acids and others do not has not been completely elucidated. It appears that it may be due to inherent barrier defects. Thus, an important factor in preventing the transformation of dandruff to seborrheic dermatitis is the minimization of inflammation.
The most important question is how to cure and prevent dandruff. As most dermatologists know, dandruff can be controlled but not cured. Why? The causative agent Malassezia globosa is present in the air. Eventually, recolonization will occur and the growth process of the Malassezia globosa population will be reinitiated with production of free fatty acids resulting in increased epidermal proliferation and inflammation in patients with possible barrier defects. The prevention of relapse depends on decreasing the organism count, minimizing skin scale, and reducing inflammation.
Preventing relapse is then based on effective maintenance therapy. Since maintenance therapy is long term, it would then seem prudent to look at products that are available in the over-the-counter realm and determine how best to use them for an effective preventative routine. This was exactly the question posed by Combe, Inc., a large manufacturer of hair and scalp care products. They provided an educational grant to look at how their products might best be used as part of a maintenance routine for dandruff and the prevention of seborrheic dermatitis.
This research was undertaken by enrolling a total of 60 male or female subjects 18 years or older with moderate dandruff and scalp pruritus into a 2-week study. The total enrollment was divided into three treatment groups of 20 each. Group I applied a topical 1% hydrocortisone product twice daily, once in the morning and once in the evening. Group II applied a topical 3% salicylic acid product twice daily, once in the morning and once in the evening. Group III applied a topical 3% salicylic acid product in the morning and a topical 1% hydrocortisone product in the evening. Evaluations were performed at baseline, after one week of treatment, and after two weeks of treatment. The study investigator evaluated the subjects for scalp scale and scalp erythema, while the subjects self-assessed their scalp itch via self-assessment questionnaire. In addition, scalp scale scrapings were collected and analyzed to gain further insight into scalp scale morphology. The rationale was to determine the contribution of scalp scale and inflammation to the maintenance phase of dandruff treatment.
Some of the most interesting data obtained from the study was the scalp scraping assessment. The scalp scrapings were obtained by scratching the scalp with a microscope slide and examining the quality of the scale removed for stickiness, flakiness, coarseness, abundance, and overall impression under a dissecting microscope. It was interesting to note that there was no statistically significant difference between those subjects using the salicylic acid preparation alone and those using the hydrocortisone preparation alone for the parameters evaluated. However, statistically significant improvement in all parameters was noted for the group using the salicylic acid preparation in the morning and the hydrocortisone preparation in the evening. This means that the scalp skin proliferation is intimately associated with inflammation and both keratolytics and anti-inflammatories must be used simultaneously to improve the appearance of scalp scaling.
The dermatologist visually assessed flaking, erythema, excoriation, and overall scalp appearance. There was a statistically significant (p=0.03) difference in excoriation noted at week 2 between the hydrocortisone twice daily and the salicylic acid twice daily. The hydrocortisone twice daily performed better at reducing excoriation, which might be expected due to its anti-inflammatory effect. The salicylic acid am and hydrocortisone pm group performed better than the salicylic acid twice daily group at week 2 in terms of erythema (p=0.02), excoriation (p=0.03), and overall assessment (p=0.01). This is probably again due to the hydrocortisone anti-inflammatory effect, which accounted for the reduction in erythema and excoriation.
This study helped to reinforce in my mind the interrelationship between scaling and inflammation in the maintenance phase of dandruff therapy. Certainly, the ideal would be to completely eliminate the organism forever from the scalp, but this is unfortunately not possible. The growth of the Malassezia must be minimized while reducing the scaling that provides a suitable protective home for growth. Keratolytics thus play an important role. Shampooing frequently to remove the sebum, which provides a nutritional source for the Malassezia is also important. Lastly, reducing the inflammation is most important to decrease the reactive proliferative scaling and the symptoms that accompany dandruff. Dandruff is a disease in need of chronic attention utilizing a variety of modalities to achieve optimal results.