A woman has slowly progressive hair loss over both temporoparietal areas of her scalp. What is the cause of this hair loss?
Over a 10-year-period, a 29-year-old woman had developed a marked decrease in the density of hair over both temporoparietal areas of her scalp (Figure 1). The hair loss had been slowly progressive. The hairline was preserved and the density of the hair over the occipital and vertex areas was relatively unaffected. Examination of the scalp revealed hairs of differing diameter, but no pustules or hair tufting. Many of the follicular orifices were lost (Figure 2). Scalp biopsy showed a decreased number of follicles, which were irregularly distributed and extended to variable depths in the scalp. There were increased fibrous tracts but no significant perifollicular inflammation (Figure 3).