Back to Articles Main Page Shaving and Hirsutism: Does it Make it Worse? Ricardo Azziz, M.D., M.P.H. Professor Physiology of Hair Growth: There are fifty million hair follicles (pilo-sebaceous units) covering the body, of which 20% are in the scalp. The only areas free of hair follicles are the soles of the feet, the palms of the hands and the lips. There are very few new hair follicles formed after birth, and their number begins to decrease after age 40 years. There are racial and ethnic differences, with Caucasians having more hair follicles than Blacks, which have more than Asian individuals. There is no sexual difference in hair follicle numbers within each racial/ethnic group. The visible difference in appearance between men and women does not relate to the number of hair follicles, but rather to the quality of the hair within these follicles.    Hair is composed of compressed keratinized melanocytes which grow toward the skin surface from the dermal papilla. The hair shaft grows within the outer hair sheath which forms part of the epidermis. There are three phases to hair growth. The active growing phase (anagen) is followed by an involutional stage (catagen), in which the hair stops growing and the hair bud shrinks. The (telogen) phase, in which the hair is shed, completes the growth cycle. Telogen hairs are lost as newly growing hairs displace them. The length of the hairs (e.g. the short hairs of the forearm compared to the long hairs of the scalp) are a result of the longer growing phase of scalp hairs compared to that of forearm hairs.    Hair appears to lengthen continuously because the growth cycles of the different hair follicles are in dysynchrony with each other. While some are in the anagen phase, others are in telogen. Hormonal shifts within the body (e.g. starting or stopping birth control pills, pregnancy and/or delivery) can lead to a synchronization of the growth cycle of the different follicles with the impression of increased growth and subsequently increased shedding. This situation usually resolves spontaneously, although it may take up to 12 months for all effects to disappear.    There are three general types of hair. Lanugo is a dense, soft unmedullated hair over the surface of the fetus which is shed sometime late in gestation or early postpartum. Vellus hairs are the soft, fine unmedullated and usually nonpigmented hair that covers the apparently hairless areas of the body. They usually measure less than 2mm in length. Terminal hairs are longer, coarse, and medullated. This hair makes up the eyebrows, the eyelashes, and the scalp hairs, and can be transformed by a number of hormones, particularly androgens, to produce terminal hairs. However, this transformation is not reversible.    It is clear that the majority of patients with hirsutism demonstrate an underlying endocrine disorder (i.e. androgen excess) which will respond to the combined approach of hormonal therapy and mechanical removal of the hairs. Optimum therapy involves hormonal suppression, androgen blockade and electrology. Nonetheless, many patients opt for shaving as a temporary hair removal measure (Richards,et al., 1990). Furthermore, some dermatologists are actually recommending that hair be shaven 1-3 days prior to electrology (Richards, et al., 1996). We also have recommended for some time that, if appropriate, patients may shave during the initial six months or so of hormonal therapy, prior to beginning electrology. This recommendation has been based on the need for cosmetic control of the patient, as well as our need to determine whether the recommended hormonal therapy is actually improving the patient's hair growth. In this regard, a quick way of determining whether hair growth is decreasing is to determine the days needed between shavings (i.e. shaving intervals), as determined by the patient. Although subjective, the less frequent the patient feels she needs to shave the more obvious her response to hormonal therapy. In addition, some of the methods devised for the objective measurement of hair growth in experimental protocols also requires patients to shave at regular intervals. (Azziz, et al., 1996).    Nonetheless, there are those who have clearly voiced their concern that shaving in patients with hirsutism may result in a growth rate and hair thickening. Following we will review the pertinent information, the pros and cons of shaving in hirsutism, and formulate some recommendations. 1. The Impact of Shaving in Men: The majority of early studies determining the impact of shaving on hair growth were performed in men. Furthermore, many of these studies suffered from the fact that they actually investigated the effect of shaving on facial beard in men, who were already shaving this skin area for many years. These early studies have been reviewed by Saitoh,et al. (1967) and Peereboom-Wynia (1972). In an attempt to determine whether shaving has an impact on hair that has not been previously shaven, the hair of the chest or legs of men was studied. Saitoh and colleagues (1967) had eleven men shave their chest hair with a safety razor and shaving creme. Hair growth rates were measured using the glass capillary method and the subjects were asked to shave twice, at seven day intervals. Sixtysix chest hairs in each of the men were assessed. The two shaving intervals appeared to have no impact on the hair growth rate.    Evaluating repeated shaving, Kim, et al. (1961) studied the effect of shaving on hair growth of the leg in nine normal males. Shaving was performed three times weekly with an electric shaver, for a total of 24-52 shaves over a period of four months. The corresponding area on the contralateral (unshaven) to the leg was used as control. In this study the number of hairs in anagen (i.e. in active growth) was increased in the shaven areas compared to controls. However, this apparent stimulation of hair growth by shaving was found to diminish after a period of 6-10 weeks. Alternatively, Lynfield and MacWilliams (1970) studied the effect of repeated shavings with razor and hot water over the inner aspects of the leg in five healthy males in their 20s, with the contralateral leg serving as control. Subjects shaved between 9-19 weeks at a rate of once weekly. In this study there was no significant difference in the hair growth rate, width, or weight of the hairs in shaven or unshaven areas, nor was there any coarsening of the individual hairs which could be ascribed to the repeated shaving. In conclusion, studies determining the impact of repeated shaving on previously unshaven hair in men are few and provide conflicting results. Nonetheless, it appears to primarily indicate that if there is an effect, it is temporary. 2. The Impact of Shaving in Hirsute Patients: It is unclear whether studies on the chest or leg of men can be extrapolated directly to the effect of shaving on facial hair growth of hirsute women. Unfortunately, there appears to be only one study determining the impact of shaving on the hair growth of hirsute women. Peereboom-Wynia (1972) studied 15 women with "idiopathic hirsutism", although three demonstrated irregular menses and hormonal androgen levels, testswere not performed. The effect of various methods of depilation on leg hair were studied, including the "lady shave", the "razor and shave", depilatory cream and depilatory resin. Patients were treated for a total of 13 weeks, with the various depilating methods implied at 1-2 week intervals. Each patient used all depilatory methods, leaving some skin untreated as controls. In this study the principal measure of hair effect assessed was hair density (i.e. the number of hairs in a predetermined skin area). The growth of new hairs was assessed in seven patients, by the bleaching method. In this study, mechanical or chemical depilation did not appear to have an effect on hair growth and density, whether the method was used once or 12 times. Nonetheless, this report suffers from the fact that it did not study the impact of shaving on facial hair growth, the most visible and concerning site to hirsute patients.    We can preliminarily conclude from this study that shaving does not appear to increase the hair growth rate and/or hair density in hirsute women, at least of leg hairs. Nonetheless, it is also very clear that further research in this area is still needed. 3. Pros and Cons of Shaving in Hirsute Patients: a.) Pros: This method of hair removal is relatively inexpensive, rapidly removes hair and is applicable to large areas of the body (TABLE 1). Furthermore, it may improve the results of electrology (Richards et al., 1986; Richards and Meharge, 1995). These investigators have recommended that patients shave between 1-5 days before electrology to ensure that only growing androgen hair epilated. They report that they consider the use of pre-electrology shaving to be of particular importance in the initial treatments, because as many as 60% of the hairs may be in telogen. These hairs are particularly difficult to eradicate permanently since they are not actively growing. Furthermore, because the telogen follicle is quite short, there is more destructive energy delivered to the skin surface, which can result in more discomfort and side effects, including folliculitis. Finally, shaving provides continuous exfoliation of the skin, which may actually improve skin texture over time. b.) Cons: Shaving may result in increased hair growth rate, albeit there is little data in this regard (TABLE 2). It definitively results in the facial hairs feeling "stubbly". This sensation probably has resulted in the reigning concept that shaving worsens facial hair growth. Furthermore, once patients begin to shave they need to continue to due to avoid the appearance of "stubble". Excessively aggressive shaving, particularly with a razor blade, may result in the development of folliculitis and ingrown hairs. This complication will further damage the skin's appearance and make electrolysis more difficult. The use of an electric shaver may be of benefit in minimizing this problem. It also should be noted that in Black patients, shaving can cause a chronic irritation of the hair follicles resulting in keloid formation at these sites and puncutate hyperpigmentation throughout the face. Furthermore, in general skin can darken from the irritation of continuous shaving. Finally, the sole act of shaving may worsen a hirsute patient's already damaged selfimage. 4. Current Recommendations: We currently do not discourage our patients from shaving, particularly during the initial six months of hormonal therapy, since this will rapidly improve cosmesis and will provide us and the patient with an inexpensive means of assessing the impact of their therapy. However, we leave the final decision in this regard to the patient, since in many patients the use of this depilitory method will further deteriorate their self-image and feelings of self worth. Furthermore we discourage the long term use of shaving, particularly in Black patients. Hence, we recommend shaving only as a temporary method of hair removal, until hormonal therapy has reduced the hair growth rate, which also improves the results of electrology. If patients do choose to shave we strongly recommend that they do so with an electric razor rather than with a straight razor. Finally, shaving should not be considered as a substitute for the permanent removal of hairs by electrology. References: 1. Kim JH, Herrman F, Sulzberger M. The effect of shaving on the growth of hair of the human glabrous skin. Berufsdermatosen. 9:197-205; 1961. 2. Lynfield YL, MacWilliams P. Shaving and hair growth. J Invest Derm. 55:170-172; 1970. 3. Peereboom-Wynia JDR. Effect of various methods of depilation on density of hair growth in women with idiopathic hirsutism. Arch Derm Forsch. 243:164-176; 1972. 4. Richards R, Uy M, Meharg G. Temporary hair removal in patients with hirsutism: A clinical study. Cutis. 45:199-202; 1990. 5. Richards R, MeKensie MA, Meharg GE. Electroepilation (electrolysis) in hirsutism. J Am Dermatol. 15:693-697; 1986. 6. Richards R, Meharg G. Electrolysis: Observations from 13 years and 140,000 hours of experience. J Am Acad Dermatol. 33:662-666; 1995. 7. Saitoh M, Uzuka M, Sakamoto M. Rate of hair growth, in Advances in biology of skin, Vol IX, Hair Growth. Eds. Montagna W, Dobson RL. Pergamon Press, New York, NY, 1967; pp.183-201. Table 1. PROS OF SHAVING IN HIRSUTISM - Inexpensive - Rapid - Applicable to large areas - May improve the results of electrology - Exfoliates facial skin - Permits an easy and mutual assessment of the results of hormonal therapy Table 2. CONS OF SHAVING IN HIRSUTISM - May result in increased hair growth rate - Results in stubble - May result in folliculitis and ingrown hairs - May result in keloid changes and skin darkening in Black patients - May negatively impact on the patients self-image  Back to Articles Main Page

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