Valley Fever Background

Valley Fever is an infection caused by the fungus Coccidioides which is found primarily in the soils of the southwestern United States and northwestern Mexico. Many people never know they have been infected with Valley Fever and get better on their own. In a group of one hundred infected patients, about 30 will have an illness lasting weeks to months, and only one to two in the hundred will get sick for the rest of their lives. Because the symptoms are often nonspecific, Valley Fever is often misdiagnosed. Even in more severe cases the diagnosis may be missed early in the disease resulting in lack of treatment and extended illness.

Who should have a test for Valley Fever?

If you are suffering for at least two weeks with three or more of the following symptoms you should consider Valley Fever Screening  (if not already diagnosed with Valley Fever):

  • Fatigue/tiredness

  • Cough

  • Trouble breathing

  • Fever

  • Drenching night sweats

  • Painful bumps on the shins

  • Muscle/joint pain

  • Chest pain

However, not everyone should have a Valley Fever Screen.

  • If you do not have symptoms, you should not be tested

  • Valley Fever Screening does not detect past infection, nor does it predict immunity to future infection

What is the body’s response to Valley Fever?

As with many infections, the body responds to Valley Fever by producing antibodies. In general, the more severe the infection, the greater amount of antibody produced. These antibodies can be detected by laboratory tests and used to help make the diagnosis of Valley Fever.

Initially, the body produces an early/IgM antibody (sometimes called a tube precipitin, or TP, antibody) which becomes detectable one to three weeks after infection. This is followed by production of late/IgG antibody (also known as complement fixing, or CF, antibody). IgM decreases over time; IgG can persist longer, but if the infection resolves itself, it too will decrease, often to undetectable levels. If the infection becomes chronic, the IgG antibody will usually remain detectable.

What is the treatment for Valley Fever?

Most people with Valley Fever recover without treatment. Experts are unsure whether antifungal treatment speeds up recovery or prevents complications. Talk with your doctor about whether you need treatment. This is particularly important because antifungal medications can cause side effects. Doctors usually monitor the progress of a patient by chest x-rays, by follow-up laboratory testing, and by the severity and duration of symptoms. This may require frequent visits to the doctor. In rare cases surgery may be required. Antibacterial agents (antibiotics) have no effect on the fungus and should be avoided unless prescribed by your doctor for another reason.

What are the medications used to treat Valley Fever? What are the side effects?

If your doctor determines that you need treatment for Valley Fever, he or she may prescribe antifungal medication. The most commonly used drug to treat Valley Fever is fluconazole, also known as Diflucan®. Other antifungal agents are available to treat more serious forms of Valley Fever (including azoles and polyenes) but are more difficult to administer and monitor; their use will be decided on by the healthcare provider. The length of treatment can vary from a few months to lifelong therapy for severe cases.

All antifungal medications can cause side effects. Depending upon the drug, these can include hair loss, nausea, vomiting, rash, diarrhea, and abdominal pain. Amphotericin B can damage the kidneys and requires close monitoring.

Talk to your doctor or pharmacist for more information.

How do I find a doctor and other information about Valley Fever?

Your primary care provider should be able to formally diagnose and treat Valley Fever. There are many resources available to help you find a physician if you don’t have one. Any of the websites listed on the back of this brochure will help guide you to the type of provider you are looking for, including specialists.

Arizona Medical Board:

Arizona Department of Health Services:  (search for Valley Fever)

Valley Fever Center for Excellence – University of Arizona:

WebMD Physician Search:

Local Community Health Centers:


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