Axillary perifollicular xanthomatosis resembling Fox-Fordyce disease

A 40-year-old woman presented with a 2-year history of intermittently pruritic pale yellow follicular papules localized to both axillae associated with decreased axillary hair growth and sweating. Skin biopsies revealed an expanded perifollicular adventitial sheath packed with xanthoma cells. There was scant lymphocytic inflammation around the follicles. Vacuolated keratinocytes were present within the infundibular region of the follicles. Serum lipid levels and serum protein electrophoresis were both normal. The features in our case overlap those described recently as a xanthomatous variant of Fox-Fordyce disease. However, in our patient the pruritus was not intense, the lesions were confined to the axillae, and the histopathological features of Fox-Fordyce disease were not confirmed. We prefer to classify our case as an axillary perifollicular xanthomatosis. It is possible that axillary perifollicular xanthomatosis is the follicular counterpart of the epidermal-based verruciform xanthomas, as both are normolipaemic and are limited to the adventitial tissue close to keratinocytes that may be the source of lipid. The finding of vacuolated keratinocytes in the infundibular region in our case may support this mechanism.