Clinicopathologic Observation of Temporal Triangular Alopecia

In a study conducted from 2000 to 2011, researchers observed the clinical and histopathologic features of temporal triangular alopecia (TTA) in 12 Korean patients, with an average age of onset at 9 years old and no sexual predilection. Most cases of TTA, which is characterized by triangular or oval hairless patches on the frontotemporal suture line, developed between ages 2 and 3, leading to speculation that TTA may be congenital. The hairless patches were typically skin-colored without signs of inflammation, scarring, hypopigmentation, or verrucous changes. Histopathologically, the affected areas had a few vellus hairs and no terminal hair, with hair follicles present but smaller than normal. Out of the 12 patients, 7 were treated with topical Minoxidil solution, but only 2 showed mild improvement, while the others saw no progression or improvement during the follow-up period.