Blastomycosis is an uncommon, but potentially serious fungal infection.
It primarily affects the lungs and skin and is caused by the fungus Blastomyces dermatitidis . The illness that can result from exposure to this organism is extremely variable. Some persons infected with Blastomyces fungus never develop symptoms. Evidence of their infection is only found by chance on a chest x-ray or blood test. Other individuals may develop an acute lung infection that begins with a fever and dry cough and may progress to weight loss, chest pain, and a persistent cough associated with the production of a thick sputum.