Hair density in African Americans

Background: The meager data on normal hair density in humans have been gath ered from a predominantly white population. Examination of scalp biopsy spe cimens from African Americans suggests that hair density in this group may be lower than in whites. This study was performed to quantify and differenc es between white and African American patients. Design: A retrospective case series of subjects who had undergone a biopsy of clinically healthy scalp skin. The 4-mm punch biopsy specimens were sect ioned, and all follicles contained within the specimens were counted at var ious levels (suprabulbar, isthmus, and infundibulum) to arrive at the numbe r and type of hairs present. Setting: Outpatient clinic in a tertiary care medical center. Patients: A consecutive sample of 22 African American and 12 white patients with clinically healthy scalp skin specimens that were studied and compare d with previously reported data. Main Outcome Measures: Patients' ago and total number of follicles, termina l follicles, vellus follicles, terminal anagen hairs, and terminal telogen hairs. Results: Total hair density (number of follicles per 4-mm punch biopsy spec imen) and total number of terminal follicles and terminal anagen hairs were significantly lower in African Americans (P<.001) than in whites and in a previously reported, predominantly white, population Conclusions: Hair density in African Americans is significantly lower than that in whites, which must be taken into consideration when evaluating a bi opsy specimen from an African American patient. Data previously collected f rom white patients may not provide adequate guidance when evaluating scalp biopsy specimens from African Americans and could lead to an incorrect diag nosis.