Congenital triangular alopecia: a case report and review.

Congenital triangular alopecia is a nonscarring loss of hair mass on the scalp's temporal regions. The area of hair diminution commonly is described as triangular or lancet shaped. Although previously considered congenital, this condition usually is noticed after 2 years of age and, more recently, is thought to be acquired. We propose that this entity be renamed triangular alopecia. Because this condition involves normal rather than inflamed skin, it does not respond to topical or intralesional steroids. It is important to make the correct diagnosis to avoid unnecessary and potentially harmful interventions. We present the case of a 10-year-old boy with triangular alopecia.