150 Hair Counts from Scalp Biopsy Specimens in Asians

HJ Lee1, SJ Ha1, JH Lee1, JW Kim1, HO Kim1, DA Whiting2. Dept. of Dermatology, College of Medicine, The Catholic University of Korea, Seoul, Korea1 and the Baylor Hair Research and Treatment Center, Dallas, Texas, USA2.

Differences in hair density have been described according to the ethnic background in white Caucasians and African-Americans. Asians have fewer hairs than Caucasians. We performed this study to assess the normal values of hair counts in Koreans. Horizontal sections of 4mm punch biopsy specimens from clinically normal occipital scalps were examined at various levels from the papillary dermis to the subcutis, and follicular counts of terminal/vellus hairs and anagen/telogen hairs were obtained. A total of 35 subjects with clinically normal occipital scalps (13 androgenetic alopecia patients, 20 patchy alopecia areata patients, and 2 healthy volunteers) were included. The numbers of total hairs, terminal and vellus hairs, and terminal anagen hairs were significantly lower (P<0.05) in Koreans compared with the published data of white Caucasians and African-Americans. Percent ratios of terminal anagen and telogen hairs were similar to Caucasians and African-Americans. Follicular density was significantly lower (P<0.05) in Koreans than in Caucasians and African-Americans. In Koreans, females had a significantly higher number of terminal hairs than males (P<0.05). Hair density is significantly lower in Koreans than in white Caucasians or African- Americans. Slight sexual difference exists in follicular counts in Koreans. Our data could be used as a guideline for determining normalcy in interpreting horizontal sections of scalp biopsies from Asians.