Causes

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 fungal particles 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
• Cancer
• Chemotherapy
• Diabetes
• Glucocorticoid medications (prednisone)
• Heart-lung conditions
• HIV
• Organ transplant
• Pregnancy (especially the first trimester)

People of Native American, African, or Philippine descent may also get more severe cases.

Symptoms

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:

• Ankle, feet, and leg swelling
• Chest pain (can vary from mild to severe)
• Cough, possibly producing blood-tinged phlegm (sputum)
• Fever and night sweats
• Headache
• Joint stiffness and pain or muscle aches
• Loss of appetite
• Painful, red lumps on lower legs (erythema nodosum)

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:

• Change in mental status
• Enlarged or draining lymph nodes
• Joint swelling
• More severe lung symptoms
• Neck stiffness
• Sensitivity to light
• Weight loss

For information on skin rashes with this infection, see: Skin lesion of coccidioidomycosis.

Exams and Tests

Tests done for milder forms of this disease include:

• Blood test to check for coccidioides infection (the fungus that causes Valley fever)
• Chest x-ray
• Sputum culture
• Sputum smear (KOH test)

Tests done for more severe or widespread forms of the infection include:

• Biopsy of the lymph node, lung, or liver
• Bone marrow biopsy
• Bronchoscopy with lavage
• Spinal tap (lumbar puncture) to rule out meningitis

Treatment

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).

Outlook (Prognosis)

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.

Possible Complications

Widespread coccidioidomycosis may cause:

• Collections of pus in the lung
• Lung abscesses
• Scarring of the lung

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).

When to Contact a Medical Professional

Call for an appointment with your health care provider if you have symptoms of coccidioidomycosis or if your condition does not improve with treatment.

Prevention

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.

Alternative Names

San Joaquin Valley fever; Coccidioidomycosis

References

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.

Updated: 4/29/2012

Reviewed by: 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.