Causes

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 (called spores) found in infected soil. The infection starts in the lungs.

After the lungs are infected, the fungus may spread to other tissues including the skin. The skin rash, or skin lesions, include erythema nodosum or erythema multiforme. They are thought to be caused by an immune response to the infection, rather than by the fungus itself.

Skin lesions are a sign of widespread (disseminated) fungal disease. Those who are at higher risk of developing widespread infection include:

• People of Native American, African, or Philippine descent
• Those with weakened immune systems due to AIDS, diabetes, or medications that suppress the immune system

Symptoms

• 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

Exams and Tests

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.

Treatment

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.

Outlook (Prognosis)

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.

Possible Complications

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

When to Contact a Medical Professional

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.

References

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

Updated: 4/15/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.