Histoplasmosis is a widespread fungal infection�that occurs worldwide. The infection gets into the body through the lungs.

Histoplasma grows in soil. The fungal particles become�airborne, and are breathed in. Soil contaminated with bird or bat droppings may have a higher concentration of mold.

The skin lesions can be caused by an immune reaction to the lung infection. In this case, lesions called erythema nodosum or erythema multiforme occur.

Skin lesions can also occur when the fungus has spread to distant organs throughout the body, including the skin, bone marrow, and the brain. This is most common among immunosuppressed people, such as those with AIDS.

The symptoms may include:

• Mouth ulcer, usually painless
• Pustules or nodules throughout the body

See also erythema nodosum and erythema multiforme.

In some cases, a biopsy of the skin lesion can identify the fungus. On the other hand, erythema nodosum and erythema multiforme skin lesions are an inflammatory reaction and usually do not have fungus in them.

Anti-fungal drugs, such as amphotericin B, itraconazole, and ketoconazole, are the usual treatment. Anti-fungals may be given intravenously depending on the form or stage of disease. In some cases, long-term suppression with anti-fungal drugs may be used.

The outlook�depends on the form of histoplasmosis and the immune system of the individual. Death can occur in some cases.

• Bacterial skin infection
• Complications of medications (for example, amphotericin B can have severely unpleasant side effects)

The skin lesions may be similar to skin problems from other infections or illnesses. Notify your health care provider if you develop any suspicious lesions on your skin so that you may be appropriately evaluated.

Histoplasmosis�may be prevented by reducing exposure to dust in chicken coops, bat caves, and other infected locations. Wear masks and other protective equipment if you work in these environments.