Pili Annulati in a Black-Haired Asian Woman.

Pili annulati (PA) is a rare autosomal dominant hair shaft disorder characterized by alternating light and dark bands along the hair shaft. It is more commonly observed in individuals with blond or light-colored hair, while cases in patients with dark hair are uncommon, as the greater amount of hair pigment can obscure the banding pattern, making it more difficult to recognize. As a valuable adjunctive tool, dermoscopy is valuable for revealing the characteristic features of PA, including alternating bright and dark bands along the hair shaft, sometimes accompanied by multiple white nodes. Here, we report a case of PA in a black-haired Asian woman with a 30-year history. Dermoscopy revealed the typical banding pattern, but notably, no obvious white nodes were observed. The positive family history further supports the familial nature of PA, although it alone is insufficient to establish an autosomal dominant inheritance pattern.