Congenital triangular alopecia (Brauer nevus).

Congenital triangular alopecia is manifested at 3 to 5 years of age by unilateral or, less frequently, bilateral patches of alopecia in the frontotemporal region. At this age the differential diagnosis is important, particularly as regards alopecia areata. Only about 47 cases have been reported, probably because the lesion is benign and nonprogressive. In 6200 patients seen in index visits, we found 7 with triangular alopecia, a frequency of 0.11%. We believe that males do not require treatment because of the later development of androgenic alopecia, but in women, surgical treatment is successful.