Triangular Temporal Alopecia Revisited.

The Editor,

A 7-year-old boy was accompanied by his mother to our dermatology department with complaint of an asymptomatic patch of hair loss over the left side of his scalp. The patch of hair loss was noticed by his mother during infancy and has been static ever since. The mother denied any preceding trauma and/or traction. There was no previous history of similar episode. Clinical examination revealed a 10 cm (across the length) sized lance-shaped patch of alopecia afflicting the left fronto-temporal region of the child's scalp [Figure 1]. Vellus hairs, otherwise apparently normal in density, were conspicuous by their presence on the patch of alopecia. No exclamation hairs were seen. There was no other surface change in the skin of the affected area of the scalp. Potassium hydroxide mount preparation of the hair from the affected scalp did not reveal fungal elements. Accordingly, a diagnosis of triangular temporal alopecia was rendered.

Figure 1

Lance-shaped patch of alopecia afflicting the left fronto-temporal region of scalp with surface depicting vellus hair

Triangular temporal alopecia was first reported by in the year 1905. More than 50 cases have been reported so far.[1] Temporal triangular alopecia/congenital triangular alopecia may be present at birth or may be acquired during the first decade of life.[2] Alopecic patch in the fronto-temporal scalp of a child is the usual scenario, however, lesions rarely occur outside the temporal area or may present during adulthood. The lancet-shaped lesions, few centimeters in width, either unilateral or bilateral, and oriented so with the tip of the “lancet” superiorly and posteriorly are the cardinal features.[3] Lesions appear hairless, but characteristically, very fine vellus hairs can be seen with magnification and trichoscopy.[4] Accordingly, the diagnosis of triangular temporal alopecia is clinical. Unfortunately, there is no effective treatment for this condition and the patches of alopecia persist for life. Surgical excision and hair grafting have been suggested.[3] Minoxidil has also been used effectively, however, with a relapse soon following treatment cessation.[5]