Regrowth of black hair in two red-haired alopecia areata patients.

The occurrence of alopecia areata (AA) in a red-haired individual is considered to be rare. We report two cases of red-haired men who were afflicted with patch-type AA. Astonishingly, the hair regrowth was coloured black, in contrast to the surrounding red hair, an event which has been reported only once in the past after cyclophosphamide administration. This phenomenon raises some interesting questions regarding the significance of pigmentation and the melanocortin-1 receptor in AA pathogenesis.