Congenital Triangular Alopecia: Is It Always Confined to the Fronto-Temporal Region?

In 2016, researchers Singh, Goyal, Thappa, and Rajesh reported a case of congenital triangular alopecia (CTA) in a 1-year-old girl, which was not confined to the fronto-temporal region of the scalp, as is typically seen with this condition. CTA is a non-scarring, non-inflammatory form of hair loss that usually presents as a triangular, oval, or lancet-shaped patch of alopecia in the fronto-temporal scalp. However, in this case, the alopecia was found in the left temporo-parieto-vertex region of the scalp. The child had been subjected to repeated tonsuring over 1 year in hopes of hair regrowth, but the alopecia persisted. Dermoscopy revealed normal follicular openings and vellus hair, and a skin biopsy showed miniaturized telogen vellus hair follicles with no perifollicular inflammation or scarring. The researchers suggested hair transplantation as a possible treatment option due to the large size of the patch. This case highlighted the rare occurrence of a large triangular patch of alopecia involving the parietal, temporal, and vertex regions of the scalp.