Hair Count in Scalp Biopsy

There were numerous studies describing the physical differences in various ethnic hair groups, but comparison of histologic parameters among ethnic groups has only been elicited in the last decade. The data on the normal control histologic parameters were gathered primarily from the white male population. Subsequently the data for normal controls of scalp biopsy specimens were reported on male blacks and Asians (Koreans). The average total hair count (vellus and terminal hairs) taken from a 4-mm punch biopsy specimen that is horizontally sectioned is somewhat different among the three ethnic groups (Table 1). Asians have the lowest hair density followed by blacks then Caucasians, who have the highest hair density, as shown by studies from Sperling and Whiting. Slightly higher hair follicular counts were observed in females of all ethnic groups (Fig. 8). Familiarity with the differences in qualitative and quantitative information provided by the plane of the scalp biopsy specimen is important in the successful interpretation of horizontal sections.