Blastomycosis
Blastomycosis (North American blastomycosis, Gilchrist's disease) is infection caused by the fungus Blastomyces dermatitidis.
Spores of Blastomyces probably enter the body through the airways when they are inhaled. Thus, blastomycosis primarily affects the lungs (see Section 4, Chapter 42) but occasionally spreads through the bloodstream to other areas of the body, including the skin. Most infections occur in the United States, chiefly in the Southeast and the Mississippi River valley. Infections have also occurred in widely scattered areas of Africa. Men between the ages of 20 and 40 years are most commonly infected. Unlike most other fungal infections, blastomycosis is not more common in people with AIDS.
Symptoms and Diagnosis
Blastomycosis of the lungs begins gradually with a fever, chills, and drenching sweats. Chest pain, difficulty breathing, and a cough that may or may not bring up sputum may also develop. The lung infection usually progresses slowly, although it sometimes gets better without treatment.
When blastomycosis spreads, it can affect many areas of the body, but the skin, bones, and genitourinary tract are the most common sites. A skin infection begins as very small, raised bumps (papules), which may contain pus. Raised, warty patches then develop, surrounded by tiny, painless abscesses (collections of pus). Painful swelling in the bones may occur. Also, men may experience painful swelling of the epididymis (a cordlike structure attached to the testes) or discomfort from an infection of the prostate gland (prostatitis).
A doctor diagnoses blastomycosis by sending a sample of sputum or infected tissue to a laboratory to be examined under a microscope and cultured.
Prognosis and Treatment
Blastomycosis may be treated with intravenous amphotericin B or oral itraconazole. With treatment, the person begins to feel better fairly quickly, but the drug must be continued for months. Without treatment, the infection slowly worsens and leads to death.
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