Fox-Fordyce disease: diagnosis with transverse histologic sections.

Fox-Fordyce disease (FFD) is an uncommon chronic follicular based dermatosis with distinctive clinical characteristics consisting of pruritic papules confined to apocrine gland-bearing skin. Histologic confirmation of this entity is often time-consuming and difficult with conventional histologic sectioning. We describe a case of FFD occurring in a 26-year-old woman, in which we used transverse histologic sectioning to easily demonstrate the histopathologic features of this condition. With conventional sectioning of a punch biopsy specimen of an affected area, more than 23 serial sections were required to locate a follicle with pathognomonic features of the disease. In contrast, only one transverse section of a biopsy specimen was required to confirm the diagnosis. We propose that transverse histologic sectioning of biopsy specimens of patients suspected of having FFD more effectively demonstrates the diagnostic features.