Summary

• An invasive infection caused by the dimorphic fungus Blastomyces dermatitidis endemic to the north central and southern US, Canada, and parts of Africa.
• Most commonly involves the lungs. Dissemination can occur, with extrapulmonary infection often seen in the skin, bones, joints, CNS, and GU system.
• Although key epidemiological factors in the history are often suggestive of the diagnosis, histopathological or microbiological examination of clinical specimens with demonstration of B dermatitidis is necessary to establish the diagnosis.
• First-line treatment for ambulatory patients is a prolonged course of oral itraconazole. Amphotericin-B is reserved for patients with more severe disease or for patients in whom itraconazole is contraindicated.
• No vaccine is available for disease prevention.