North American blastomycosis in an immunosuppressed patient.

A 49-year-old man with sarcoidosis presented with a large nonhealing verrucous and eroded lesion (of two years' duration) over the left flank. Biopsy of the lesion revealed granulomatous infiltration, and special fungal stains showed the typical broad-necked budding structure of Bastomyces dermatitidis. The patient underwent en masse surgical removal of the lesion followed by systemic administration of amphotericin B. This report emphasizes the need for skin biopsy for nonhealing ulcers of unknown etiology, reviews the natural history of North American blastomycosis, and speculates on its relationship to immunosuppression.