Understanding Coccidioidomycosis

Coccidioidomycosis is an infection caused by a fungus that is breathed in from dust in the environment. It most often causes lung infection (pneumonia). It is also known as “valley fever” because the first cases were found in the San Joaquin Valley of California.  It is still mainly found in the southwest U.S., as well as Mexico and parts of Central and South America. Coccidioidomycosis doesn’t spread from one person to another. 

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What causes coccidioidomycosis?

Coccidioidomycosis is caused by the fungus Coccidioides. This fungus lives in dry soil. It is found mainly in the Southwest. Infection can occur after breathing in spores of the fungus. The spores may get into the air during windy weather. Or they may get into the air from activities that raise dust, such as farming and construction work. Anyone who lives in or travels to areas where the fungus is found is at risk of getting infected.

What are the symptoms of coccidioidomycosis?

Many people who are infected have no symptoms. If symptoms do occur, they usually start within 3 weeks of breathing in the spores. Symptoms can range from mild to severe. Common symptoms include:

  • Extreme tiredness (fatigue)

  • Not feeling well

  • Fever

  • Chills

  • Night sweats

  • Cough

  • Chest pain or shortness of breath

  • Muscle aches and joint pain

  • Rash

Most people with symptoms get better within a few weeks or months. Some people are more likely to progress to severe symptoms if infected. You are more likely to have severe symptoms if you:

  • Have a weak immune system. This might be from cancer or HIV.

  • Take medicines that suppress the immune system

  • Are pregnant

  • Have diabetes

  • Are older than 60

  • Are African American or Filipino

How is coccidioidomycosis treated?

Treatment depends on how serious the infection is.

  • More than half of people infected have no symptoms at all. Mild cases need little more than treatment of symptoms. You may use over-the-counter medicines to help relieve symptoms.

  • Severe cases need treatment with antifungal medicines. These help kill the fungus causing the infection. You may need to take these for 3 to 6 months or longer. You may also need to take these medicines if you are at high risk for complications.

What are the possible complications of coccidioidomycosis?

Complications are more likely to occur with severe cases. They can include:

  • Long-term (chronic) symptoms such as cough, fever, tiredness (fatigue), or bloody sputum

  • Severe pneumonia and other lung problems, such as nodules and cavities. These can cause more sputum, shortness of breath, and less stamina.

  • Spread of the infection to other parts of the body. These areas may include the brain, spinal cord, skin, joints, or bones.

How can I prevent  coccidioidomycosis?

If you live in areas where coccidioidomycosis can occur, the tips below may help reduce the risk for infection. During windy weather or dusty conditions:

  • Stay indoors. Also keep your windows and doors closed at home.

  • Keep car windows closed when you are driving.

  • Wear a mask that covers your nose and mouth if you have to be outdoors.

When should I call my healthcare provider?

Call your healthcare provider right away if you have any of these:

  • Severe weakness, tiredness, or fever that doesn’t get better

  • Coughing with blood-tinged mucus

  • Painful red or brown rash on the legs that may spread to other body areas

  • Unexpected weight loss

  • Skin sores

  • Swollen lymph nodes

  • Joint swelling

  • Confusion, stiff neck, or seizures