Blastomycosis is caused by the fungus, Blastomycosis dermatitidis, which is commonly found in soil and wood. The fungus usually enters the body through the lung, where it is inhaled. Infections are rare in those with health immune systems.

The infection may cause:

• Pneumonia or bronchitis: 60 to 90% of people
• Skin infection: 40 to 80% of people
• Osteomyelitis: 25 to 50% of people
• Bladder infections or kidney infections: 10 to 30% of people