Clinical manifestations and treatment of blastomycosis

Blastomyces dermatitidis and Blastomyces gilchristii are the etiologic agents of blastomycosis. Blastomyces spp. are thermally dimorphic fungi that grow as a filamentous mold in the environment and as a yeast in human tissues. Blastomycosis is endemic to North America, particularly states/provinces bordering the Mississippi, Ohio and St. Lawrence Rivers, and the Great Lakes. The clinical manifestations of blastomycosis are broad, ranging from asymptomatic infection to acute respiratory distress syndrome and death. Extrapulmonary dissemination to the skin, bone, and central nervous system can occur. While culture and non-culture diagnostic tests are available, a high index of clinical suspicion is essential for prompt diagnosis. Treatment guidelines published by the Infectious Disease Society of America and the American Thoracic Society recommend the use of polyene or azole antifungal agents, with selection influenced by disease severity, site of infection, immunosuppression and pregnancy.