Clinicopathological study of Fox-Fordyce disease.

Fox-Fordyce disease (FFD) is a rare skin disease manifesting as multiple pruritic follicular papules involving the skin-bearing apocrine glands. Reports of FFD in Asian people are scant. In this retrospective study, we describe the clinicopathological findings of five cases of FFD affecting Taiwanese subjects. Clinically, all patients presented with numerous uniform, 2-3-mm, skin-colored to light brown, dome-shaped papules with smooth surface, which were distributed in the apocrine gland-containing areas. Pruritus varied from mild to severe. The histopathology is characterized by focal spongiosis in the upper infundibulum with perifollicular fibrosis and lymphohistiocytic infiltrate. FFD needs to be differentiated from lichen amyloidosis, Darier's disease, syringoma, lichen simplex chronicus and spongiotic dermatitis clinically or pathologically. The findings of focal spongiosis in upper infundibulum associated with a perifollicular lymphohistiocytic infiltrate can facilitate the diagnosis of FFD.