Definition of Skin lesion of histoplasmosis:

Skin lesions of histoplasmosis are a symptom of widespread infection with the fungus Histoplasma capsulatum.

This article talks about skin lesions due to histoplasmosis only. For more general information on the disease, see: Histoplasmosis

Causes, incidence, and risk factors:

Histoplasmosis is a fungal infection. It occurs throughout the world. In the United States, it is most common in the southeastern, mid-Atlantic, and central states.

Histoplasma fungus grows in soil. When particles become airborne, they can be breathed into the lungs, causing infection. Soil contaminated with bird or bat droppings may have a higher concentration of the fungus.

After infecting the lungs, the fungus travels to distant areas of the body, including the skin. This is a sign of widespread (disseminated) infection. Skin lesions can be caused by an immune response to the infection (usually a rash called erythema nodosum or erythema multiforme), or by the fungus itself when it spreads to the skin.

Widespread infection is most common in immunosuppressed people, such as those with AIDS or cancer, or those who have had a transplant.