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. Immunosuppressedindividuals, 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.

• Skin lesion of the initial (primary) infection
  • Erythema multiforme (target lesions)
  • Erythema nodosum
  • Papular rash
• Skin lesion of widespread (disseminated) disease: papule, pustule, nodule, or plaque
  • May form abscesses
  • May ulcerate
  • Most often on the face

The diagnosis depends on the stage of infection (primary or disseminated). If disseminated disease is suspected, the doctor may do a skin biopsy to look for the fungus in a skin lesion.

This infection is treated with antifungal medications. Oral or intravenous (directly into a vein) drugs will be used, depending on the form and stage of the disease. Antifungal agents used include amphotericin B, itraconazole, ketoconazole, or fluconazole. People with disseminated disease and a suppressed immune system may need long-term treatment.

What happens depends on the stage and extent of the infection, as well as the person's immune system. The highest mortality rate is seen in immunosuppressed people with disseminated disease.

• Additional skin infections caused by bacteria
• Complications related to medications (such as severe side effects)
• Skin abscess

There are many types of skin lesions, and they can be hard to tell apart. Notify your medical provider if you develop skin lesions and suspect this condition, because you will need to be tested.

Galgiani JN, Ampel N, Blair JE, et al. Coccidioidomycosis. Clin Infect Dis. 2005;41:1217-1223.

Galgiani JN. Coccidioidomycosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 354.