A skin lesion of blastomycosis is a symptom of an infection with the fungus Blastomyces dermatitidis. The skin becomes infected as the fungus spreads throughout the body.
Blastomycosis is a rare fungal infection. It is most common in the central and southeastern United States, and in Canada, India, Israel, Saudi Arabia, and Africa. A person gets infected by inhaling fungal particles that are found in moist soil, particularly where there is rotting vegetation. People with immune system disorders are at highest risk for this infection.
The fungus enters the body through the lungs, infecting them. The fungus then spreads (disseminates) to other areas of the body. The infection may affect the skin, bones and joints, genitourinary tract, and other systems.
Skin symptoms occur in about 80% of people infected with blastomycosis. It is a sign of widespread (disseminated) infection. Skin lesions may look like warts or like ulcers. They may also affect the nose and mouth.
With time, these lesions can lead to scarring and loss of skin color (pigment). The lesions are most frequently found on exposed body areas.
The infection is diagnosed by identifying the fungus in a culture taken from a skin lesion. This usually requires a skin biopsy.
This infection is treated with antifungal drugs such as amphotericin B, itraconazole, ketoconazole, or fluconazole. Either oral or intravenous (directly in the vein) drugs are used, depending on the form and stage of the disease.
What happens depends on the form of blastomycosis and the individual's immune system. In immunosuppressed individuals, long-term treatment may be required to prevent symptoms from coming back.
Some of the skin problems caused by blastomycosis can be similar to skin problems caused by other illnesses. Tell your doctor if you develop any worrisome skin problems.