Coccidioidomycosis—also called valley fever—is a fungal infection that starts in the lungs, and in rare cases spreads to the rest of the body. According to the California Department of Health, approximately 150,000 people per year in the United States contract a valley fever infection (CDPH).
Most cases of valley fever are acute, meaning the fungal infection is contained in the lungs. The University of Arizona Valley Fever Center for Excellence estimates there is about a one percent chance that the fungal infection will spread past your lungs to other parts of your body (VFCE).
If the infection does spread past your lungs, it is called disseminated coccidioidomycosis. Chronic Coccidioidomycosis is when your symptoms last a long time or keep coming back.
You can get valley fever by inhaling dust from soil that contains Coccidioides immitis or Coccidioides posadasii fungi. The fungi are commonly found in soil of the desert regions of the southwestern United States, Mexico, Central America, and South America. Arizona is a hotbed for valley fever.
You are at risk of getting valley fever if you spend time in an area where Coccidioides fungi are endemic (commonly found). Your risk is increased if you are in an endemic area when the soil is disturbed by weather or human activities such as landscaping or construction. This causes the release of fungus spores into the air, where they are easily inhaled.
You also have an increased risk of getting the chronic or disseminated forms if you have a weak immune system, have diabetes, or are elderly. Pregnant women and new mothers are more prone to developing a serious form of valley fever.
About 60 percent of people who have been exposed to the fungi do not show symptoms (VFCE). People with symptoms generally start experiencing them five to 21 days after they are exposed. Symptoms vary depending on the form of valley fever you have.
The most common symptoms of the fungal infection are similar to those of a fever or cold. Because of this, you may not realize you have valley fever. The signs of acute valley fever can include fatigue, cough, headache, joint pain, and fever, though it sometimes occurs with no symptoms at all.
If the fungus spreads through your bloodstream to the rest of your body, the signs will be more pronounced. You may experience the following symptoms and complications:
- erythema nodosum (painful red bumps under the skin on the lower legs)
- painful lesions (areas of abnormalities or damage) in your skull, spine, or other bones
- altered mental state (confusion, mood swings, etc.)
- joint swelling
- sensitivity to light
- weight loss
- enlarged lymph nodes
- draining lymph nodes
- cavitary pneumonia (abnormal cavities in the lungs)
- neck stiffness
- meningitis (inflammation of the membranes and fluid surrounding the brain and spinal cord)
The infection may become chronic if it does not completely go away. This means you may experience long-term symptoms, or have symptoms that come and go. Chronic coccidioidomycosis symptoms are similar to those of tuberculosis and include:
- low fever
- chest pain
- blood-tinged phlegm
- lung nodules (small growths in the lungs)
- chronic (long-term) pulmonary coccidioidomycosis, which can develop 20 years or more after you are originally infected with the fungus
Your doctor may test a sample of your mucus or perform a blood test to detect the fungus in your body. If you are having breathing difficulties, your doctor may also perform an X-ray to see if there are any changes in your lungs.
If the fungal infection has spread throughout your body and you have severe symptoms, your doctor may perform one or more of the following tests:
- lymph node, lung, liver, or bone marrow biopsy (a surgical procedure where a small sample of tissue is removed and tested for the presence of fungus)
- bronchoscopy with lavage (a procedure that cleanses the lungs with saline fluid to obtain a tissue sample)
- spinal tap (a procedure where a small amount of spinal fluid is removed using a syringe) to rule out meningitis
Treatment may include home care, medication, or surgery, depending on your symptoms.
Most people get better without treatment. Your doctor may recommend bed rest and home flu treatments until you feel better.
Your doctor may prescribe an antifungal medication to kill the fungus. This treatment is more likely if you have a weakened immune system or if your symptoms do not go away with home care alone.
If you have chronic or severe valley fever, you may need surgery to remove the infected parts of your lungs.
Your overall health and the type of valley fever that you have are what will determine your prognosis. You will likely recover from the acute form without any complications. With medication, you will also likely recover from the chronic form; however, you may experience relapses. Though it is more rare than other forms, the death rate for the disseminated valley fever is high.
There is no sure way to completely prevent valley fever in endemic areas. You can limit your exposure to the fungus by wetting soil with water before digging or gardening and by wearing a filtration mask that can filter 0.4 µm size particles.