Coccidioidomycosis is an infection caused by inhalation of spores of Coccidioides immitis, a fungus found in the soil in certain parts of the southwestern U.S., Mexico, and Central and South America.

Alternative Names

Valley fever

Causes, incidence, and risk factors

Coccioioides infection begins in the lungs, following inhalation of the spores. About 60% of infections resolve without ever causing symptoms and are only recognized by a positive coccidioidin skin test . In the remaining 40% of infections, symptoms range from mild (such as cold-like or flu-like symptoms) to severe, such as pneumonia. In less than one percent of infections, widespread disease occurs when the fungus spreads from the lungs through the blood stream to involve the skin, bones, joints, lymph nodes, and central nervous system or other organs. Individuals of African or Philippine descent and people with a weak immune system, such as patients with AIDS or diabetes or those taking immunosuppressive medications, can develop more serious infections. Occasionally the acute infection can develop into a chronic pulmonary (lung) disease or can "reactivate" after a long latent period. A history of travel to an endemic region is the key to suspecting coccidioidal infection. Arizona, California (especially San Joaquin Valley), and to a lesser extent western Texas are endemic regions in the USA.

Signs and tests

Sputum smear (

KOH test or Papanicolaou stain)

Biopsy of lymph node or lung

Sputum culture

Serum

coccidioides complement fixation titer

CBC

with

differential

Chest X-ray

Coccidioidin or spherulin skin test

Treatment

The

acute disease is almost always benign and goes away without treatment. Bedrest and treatment of flu-like symptoms until fever disappears may be recommended. In severe forms of the disease ( disseminated coccidioidomycosis ), antifungal treatment with amphotericin B, fluconazole, or itraconazole can be used. The best length of treatment with these medications has not been determined for this disease.

Expectations (prognosis)

The outlook in milder cases is usually good. Disseminated coccidioidomycosis can be serious, particularly in people with weakened immune systems.

Complications

Coccidioidomycosis - chronic pulmonary

Coccidioidomycosis - disseminated

Calling your health care provider

Symptoms develop that suggest

coccidioidomycosis

Symptoms worsen or do not improve with treatment

New symptoms develop

Prevention

Avoiding travel to regions where this fungus is found may prevent risk of developing this disorder. However, this is not practical or possible for many people. It may be prudent to try to avoid contact with soil in these regions if you have a weakened immune system due to HIV or other conditions.