Leukonychia punctata and pitted nails in alopecia areata.

A 36-year-old man with long-standing alopecia areata was noted to have both leukonychia punctata and pitted nails. Histopathologic evaluation of the leukonychia punctata revealed multiple discrete parakeratotic foci throughout the entire thickness of the nail plate, suggesting both proximal and distal matrix involvement. The finding of shallow pits lined with residual adherent parakeratotic cells suggests that the pathogenesis of nail pits in alopecia areata is similar to that of psoriasis; a result of shedding of parakeratotic cell aggregates from the nail plate.