Skin lesions of coccidioidomycosis are a symptom of infection with the Coccidioides immitis fungus.

Coccidioidomycosis is a fungal infection most commonly seen in the desert regions of the southwestern United States, and in Central and South America. You get it by breathing in fungal particles from soil. The infection starts in the lungs.

About half of infected people have mild symptoms or no symptoms at all. Immunosuppressed individuals, such as people with AIDS, cancer, or who've had a transplant, are at higher risk of severe, widespread (disseminated) disease.

Skin rash can occur in the early stages of coccidioidomycosis (during primary lung infection). These include erythema nodosum or erythema multiforme. These rashes usually go away without treatment. They are thought to be caused by an immune response to the infection, rather than by the fungus itself.

After the lungs are infected, the fungus itself may spread to other tissues including the skin, and lead to various skin lesions including papules, nodules, and ulcers. These lesions contain fungus within them and are a sign of widespread (disseminated) fungal disease.