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 impor
tant, particularly as regards alopecia areata. Only about 47 cases hav
e been reported, probably because the lesion is benign and nonprogress
ive. 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.