Ilia Jbankov
FNP-BC Medcor Provider

Despite having many age-old names, such as coccidioidomycosis, desert fever, cocci, San Joaquin Valley fever, California fever, and desert rheumatism, Valley fever is a modern-day reality that has been on the rise in the United States in the last two decades. Even though it was discovered over a century ago, Valley fever remains a mystery in the minds of many. So, let’s take a look at some of the most important questions people have about Valley fever and attempt to unravel some of its mysteries.

What is Valley fever?

Valley fever is an infection caused by the Coccidioides fungus. It occurs when someone inhales its fungal spores. Coccidioides lives in the soil in arid and warm climates such as the Southwestern U.S., parts of Mexico, and Central and South America. In the U.S., the majority of Coccidioides fungi are found in Arizona and California. The Coccidioides fungus has also been found in Nevada, New Mexico, Utah, Texas, and parts of Washington state.

How can one get Valley fever?

Valley fever may occur at any time of year, but it is more common in the summer when the soil is especially dry. Events that disrupt the dry soil, such as windy weather, dust storms, or earthquakes, propel fungal spores into the air making it more likely to be inhaled. Fungal spores, when inhaled, can replicate inside the lungs, leading to infection.

The inhalation of a single microscopic spore can lead to Valley fever, but according to the CDC, most people who inhale Coccidioides spores do not get sick. While extremely rare, it is also possible to get Valley fever if the fungus comes in contact with a wound or cut in the skin. Because Coccidioides spores can survive on surfaces such as cargo, clothing, backpacks, envelopes, and inside mail packages, you can get Valley fever without traveling to an area known to have the Coccidiosis fungus. Fortunately, Valley fever does not spread from person-to-person.

What are signs and symptoms of Valley fever?

Valley fever can have a range of symptoms. It may be difficult to diagnose as these symptoms may mimic other conditions. The symptoms may include:

  • Cough                                               
  • Chest pain
  • Shortness of breath
  • Coughing up blood (hemoptysis)
  • Fever
  • Fatigue
  • Night sweats
  • Weight loss
  • Headache
  • Rash
  • Muscle and joint pains
  • Joint swelling

Is Valley fever common?

About 10,000 to 20,000 cases of Valley fever are reported to the CDC every year, but experts believe that actual cases of Valley fever in the U.S. could include hundreds of thousands of cases every year. This discrepancy may be because Valley fever is often unrecognized, misdiagnosed, and underreported. As more individuals travel, live, and work in areas inhabited by the Coccidioides fungus, the more common Valley fever becomes.

Are there risk factors for Valley fever?

Anyone, regardless of age or health status, can get Valley fever. Certain people may be at higher risk of getting Valley Fever include those who live, work, or travel to an area in which the Coccidiosis fungus can be found. Examples include:

  • Farmers, construction workers, landscapers, gardeners, and people who use excavators
  • Individuals who perform recreational activities such as dirt biking
  • Individuals who travel to these areas and spend time outdoors hiking or camping

Who is most at risk for developing serious illness from Valley fever?

The majority of people who have Valley fever experience milder symptoms. Some people develop severe, long-lasting, complicated illnesses which can potentially lead to life-threatening illness.

People who are more likely to have more serious illness or more likely to develop complications include:

  • People aged 60 or older
  • Pregnant women
  • People who are diabetic
  • People with weakened immune systems including people with HIV/AIDS, autoimmune disorders, or people who are on steroids or chemotherapy medications
  • People who are of African or Filipino descent

What is the course of illness for Valley fever?

The majority of people who inhale Coccidioides spores may not become ill. Many of those who become ill develop the symptoms of walking pneumonia. This is a milder type of pneumonia and an individual is often able to continue day-to-day activities without needing specialized treatment or significant rest. 

However, there are those who have more serious symptoms and require specialized treatment. Some people develop disseminated disease which occurs when fungus enters the blood stream and infects different tissues and organs. This can lead to complications such as rashes, skin lesions, joint swelling, and even chronic inflammation in the brain (meningitis).

What is the evaluation and treatment for Valley fever?

If you live, work, or travel to an area where Coccidioides is common and develop symptoms of Valley fever that do not resolve on their own or are severe enough to interfere with your day-to-day activities, you should see your healthcare provider. Your healthcare provider will perform an evaluation which may include blood tests, sputum culture, and diagnostic imaging such as a chest X-ray or a CT scan.

If Valley fever is confirmed, treatment and follow-up depend on symptom severity. Mild or improving symptoms can usually be treated with over-the-counter medicines and home remedies. More severe symptoms usually require a referral to a specialist who will likely prescribe an anti-fungal medication for a period of several months. For such cases, follow-up visits with a specialist for chest X-ray and blood tests may be needed. Additionally, patients who experience significant fatigue or weight loss due to Valley fever may be referred to physical therapy for reconditioning.

Is it possible to prevent Valley fever?

Unfortunately, avoidance of breathing in fungal spores from the air is hard to do when you live, work, or travel to a destination known for its robust Coccidioides population. However, following a few guidelines can help minimize your exposure to the fungus, especially at times when its presence in the air is high. These tips are especially important for individuals with risk factors.

  • If your activities or work take you outside during windy or dusty weather or you work at a construction/excavation site, wearing an N95 mask can protect you.
  • Stay inside and close your windows during windy and dusty conditions.
  • Avoid activities, such as gardening, digging, and yard work, that may expose you to dust and soil. This is especially important during hot and dry seasons.
  • Use filters inside your home, work office, and car. Replace your filters as indicated per manufacturer recommendations.
  • Cover any cuts, abrasions, and wounds on your skin. Remember, the chances of getting Valley fever through the skin are minimal, yet they still exist!
  • Finally, take good care of your four-legged friends. Pets, particularly dogs, may get Valley fever as well. 

This article is not intended to diagnose or treat any condition or to give medical advice. Always consult your primary care provider for healthcare instructions. External links are provided as references and do not indicate an endorsement by Medcor. External links are subject to other sites’ terms of use and privacy policies.


Centers for Disease Control and Prevention, “Valley Fever (Coccidioidomycosis) Risk & Prevention,” November 19, 2020,, “Causes of valley fever (coccidioidomycosis),” October 23, 2015,

Nina Bai, “Valley Fever Is On the Rise – But No One Knows How It Picks Its Victims,” University of California San Francisco, October 2, 2019,

Medscape, “Valley Fever: Timely Diagnosis, Early Assessment, and Proper Management,”