ABSTRACT
Several authors have assessed the effect of aging on hair density by studying the scalp surface (i.e., clinical rather than histological evaluation). The results of these studies suggest that the density of hair follicles and the average diameter of individual follicles decrease steadily with aging (2-6). There are no recent data (within the past 40 years) to confi rm this, and in particular there have been no studies based on the histological evaluation of scalp biopsy specimens taken from a suffi ciently large population of “normal” individuals of various ages. However, Whiting (7) has presented data on 852 patients (almost all female) with “diffuse alopecia,” that is, without clinical evidence of androgenetic alopecia. When divided into age groups by decades (from 20-29 to 90-99), there was only a modest reduction in total hair numbers with time, with a 10% reduction (as compared with the youngest group) in the 70-79 group, and a 21% reduction in the 80-89 group. The data suggest that decreased hair density is not an inevitable consequence of aging, and noticeable hair loss should only be expected in the very elderly. However, the data were pooled and did not exclude the possibility of outliers, namely, those few patients whose decreased hair density occurred prematurely, for example, in the 6th or 7th decade of life.
