An infection caused by coccidioides fungal spores.

Valley fever, also called coccidioidomycosis, is caused by two types of fungi found in the soil in some areas. Anything that stirs up soil, such as farming, the wind or construction, can send fungal spores into the air. Breathing in the spores can cause infection. People with suppressed immune systems are particularly at risk.

Some people who breathe in the fungal spores have no symptoms, but for other people symptoms can range from mild to severe. Symptoms can start 1 to 3 weeks after contact with the spores. Symptoms might include fever, cough, tiredness, shortness of breath or rash.

Mild infections may clear up with no treatment. People at high risk for complications may be prescribed antifungal medicine.