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Valley fever is an infection that occurs when the spores of the fungus Coccidioides immitis enter your body through the lungs.
San Joaquin Valley fever; Coccidioidomycosis
Causes, incidence, and risk factors
Valley fever 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 the fungus from soil. The infection starts in the lungs.
Valley fever may also be called coccidioidomycosis.
Traveling to an area where the fungus is commonly seen raises your risk for this infection. You are also more likely to develop a serious infection if you have a weakened immune system due to:
Anti-tumor necrosis factor (TNF) therapy
Glucocorticoid medications (prednisone)
Pregnancy (especially the first trimester)
People of Native American, African, or Philippine descent may also get more severe cases.
Most people with valley fever never have symptoms. Others may have cold- or flu-like symptoms or symptoms of pneumonia. If symptoms occur, they typically start 5 to 21 days after exposure to the fungus.
Common symptoms include:
Rarely, the infection spreads from the lungs through the bloodstream to involve the skin, bones, joints, lymph nodes, and central nervous system or other organs. This is called disseminated coccidioidomycosis.
People with this more widespread form may become very sick. Symptoms may also include:
Skin lesions of coccidioidomycosis are often a sign of widespread (disseminated) disease. With more widespread infection, skin sores or lesions are seen most often on the face.
Signs and tests
Tests done for milder forms of this disease include:
Tests done for more severe or widespread forms of the infection include:
The disease almost always goes away without treatment. Your health care provider may recommend bedrest and treatment for flu-like symptoms until your fever disappears.
If you have a weakened immune system, you may need antifungal treatment with amphotericin B, fluconazole, or itraconazole. The best length of treatment with these medications has not been determined.
Sometimes surgery is needed to remove the infected part of the lung (for chronic or severe disease).
How well you do depends on the form of the disease you have and your overall health.
The outcome in acute disease is likely to be good. With treatment, the outcome is usually also good for chronic or severe disease (although relapses may occur). People with disseminated disease have a high death rate.
Widespread coccidioidomycosis may cause:
These problems are much more likely if you have a weakened immune system.
A chronic form of this infection can develop 20 or more years after first infection. Lung abscesses can form and rupture, releasing pus (empyema) between the lungs and ribs (pleural space).
Calling your health care provider
Call for an appointment with your health care provider if you have symptoms of coccidioidomycosis or if your condition does not improve with treatment.
Taking care of your health will help keep the disease in the benign pulmonary form. Preventing AIDS or other causes of immune system damage will usually prevent the more severe forms of the disease.
People with immune problems (such as AIDS patients and those who are on drugs that suppress the immune system) should avoid travel to areas where this fungus is found, if they want to reduce their risk of getting this rare, chronic disorder.
Galgiani JN. Coccidioidomycosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 341.
Galgiani JN. Coccidioides species. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 266.
- Last reviewed on 8/15/2012
- David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc. 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.
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This page was last updated: April 14, 2014