Blastomyces dermatitidis is a type of fungus that can cause a disease known as blastomycosis. This fungus is typically found in moist soil and decaying organic matter, particularly in areas near rivers and lakes. When spores are inhaled, they can lead to respiratory issues and other systemic infections. Infection with Blastomyces dermatitidis can affect various parts of the body, including the lungs, skin, and bones. Symptoms may include cough, fever, and skin lesions. Treatment usually involves antifungal medications, and early diagnosis is important for effective management of the disease.