Self-limited blastomycosis: a report of 39 cases.

We report 39 patients with pulmonary blastomycosis who were not treated with specific antifungal chemotherapy. Fourteen of these patients were recognized during an epidemic of blastomycosis in 1972 and did not have culturally proven disease. The remaining 25 patients were all proven instances of blastomycosis, 24 of whom had pulmonary disease only. Over a median observation period of 42 months (range: 12 to 168) one patient relapsed 52 months after the original diagnosis, while all of the others have remained clinically well. It is our belief that certain patients with blastomycosis limited to the lungs may safely be followed without specific antifungal chemotherapy until clearing occurs. These include patients with mild or no symptoms and those who have been more symptomatic but are already improving when the diagnosis is established. Worsening of the clinical picture, or evidence of extrapulmonary disease requires immediate antifungal chemotherapy.