Pili annulati associated with hair fragility: cause or coincidence?

Pili annulati is a disorder that produces a spangled appearance to the hair, caused by alternating light and dark banding of hair shafts. This phenomenon is created by abnormal cavities in the cortex of the hair shaft, which produces lighter bands seen on clinical examination. Complications of pili annulati are limited; the most noteworthy complication is increased breakage secondary to weathering of the abnormal hair shafts. We report a case of a 14-year-old adolescent girl with pili annulati and progressive hair loss of 2 months' duration. Most of her hairs were notably short, spangled, and lusterless with light and dark banding observed with handheld magnification. Light microscopy demonstrated alternating light and dark bands, and the dark bands had the typical appearance of air-filled spaces. Gentler hair grooming practices were recommended, and at a follow-up visit, the appearance of the hair had improved with darker and longer shafts. This case should alert clinicians to look for pili annulati when hair fragility is present.