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| Fig. 62.9 Lipedematous scalp in an elderly black woman, indicated by pressure applied using a pencil, yielding remarkable induration of the skin. (Courtesy of Whitney A. High, MD) |
Blacks have elliptical follicular ostia and tightly curled hair with a small mean cross-sectional area. Asians have round ostia and straight hair with a large mean cross-sectional area. Whites have round to slightly ovoid follicles with an intermediate mean cross-sectional area. Nevertheless, these remain broad generalizations, and the entire racial and genetic makeup of the individual must be considered. The angles of curvature in the spiral structure of black hair yields multiple vulnerable points along the hair shaft, making it relatively fragile and prone to breakage. This structural arrangement also inhibits effective transmission of secreted sebum down the shaft, making the hair drier and less manageable relative to other hair types. For these reasons, the hair of blacks cannot be shampooed as often as that of other racial groups. Daily washing would lead to excessive dryness and hair breakage. A moisturizing conditioner should be used after shampooing. Such differences in hair care must be considered when prescribing treatment for scalp conditions that involve medicated shampoos. When evaluating alopecia, a thorough history of hair grooming techniques used should be obtained. Specifically, questions about the use of chemical relaxers, permanent hair dyes, curling irons, hot combs, blow dryers, braids, or weaves should be inquired of, because many of these modalities cause damage to the hair shaft or the scalp. Finally, some unusual forms of alopecia, such as lipedematous alopecia (Fig. 62-9), with associated cotton-batting textural changes of the scalp, are associated nearly exclusively with black women.
High WA, Hoang MP: Lipedematous alopecia,
J Am Acad Dermatol 53:S157–S161, 2005.
McMichael AJ: Ethnic hair update: past and present,
J Am Acad Dermatol 48:S127–S133, 2003.
