Encyclopedia / C / Coccidioidomycosis



Also known as San Joaquin Valley Fever or Valley Fever, Coccidioidomycosis is an infectious illness caused by breathing in spores from the fungus Cocciodioides immitis which exists in the soil of certain arid parts of the southwestern United States, Mexico, and Central and South America.


In the U.S., it was first discovered and very prevalent in the California's San Joaquin Valley, hence its more popular name, San Joaquin Fever or Valley Fever.

Coccidioidomycosis occurs in a primary and in a secondary form. The primary form, due to inhalation of windborne spores, varies in severity from that of the common cold to symptoms resembling those of influenza. The secondary form is a virulent and severe, chronic, progressive and granulomatous (a mass of nodular tissue resulting from inflammation, injury or infection) disease resulting in involvement of cutaneous and subcutaneous tissues, viscera, the central nervous system and lungs.

Coccidioidomycosis may affect anyone, but if you are pregnant or your immune system is weak, you are especially vulnerable. The disease tends to be more serious in dark-skinned people.


Most commonly, there are no symptoms with coccidioidomycosis. Nine out of every ten people who have moved into desert areas of the southwestern U.S. test positive for this fungus within four or five years after their move. In approximately 10 percent of these, chest pain will develop. This, along with fever, chills and other flu-like symptoms, usually begins 10 to 30 days after exposure to the mold.

Nasal congestion and a mild cough may be followed by bronchitis. One to two days after the fever begins, a red spotty rash (similar to measles) appears, and knees and ankles may swell.


Usually the disease clears up without complications, although in some cases, the lesions formed in the lungs may be difficult to cure. In rare cases, this disease may recur after weeks or months. Occasionally, the infection spreads throughout the body, causing lesions in the lungs, bones and other organs.

Treatment consists primarily of rest. Antibiotics may be given to prevent secondary bacterial infection. Amphotericin B or ketoconazole may be used to reduce the risk of extra pulmonary dissemination or to obtain remission after dissemination occurs.


Do lab tests need to be done to confirm the diagnosis of Coccidioidmycosis?

Is this the primary or secondary form of this disease?

Could this lead to secondary form?

Can anything be done to prevent this from progressing to the more serious secondary form?

Do you recommend any medication to help in the treatment of this condition? What are the side effects?

What measures can be used to relieve the symptoms?

How contagious is it?

Are there any signs or symptoms which might indicate the disease is progressing and should the physician be notified?