Last Updated 05/07/2020

Authors:Joshua Malo, MD; Kenneth Knox, MD, FCCP; John Galgiani, MD

About Coccidioidomycosis

Key facts about Coccidioidomycosis
  • Coccidioidomycosis is a fungal infection that affects the lungs.
  • You can get the disease by breathing in fungal spores. These spores are in the soil.
  • It is not contagious: It cannot be passed from person to person.
  • It is treated with antifungal medication, not with antibiotics.

Coccidioidomycosis is an infection commonly called valley fever. It is caused by a fungus found in the soil in the southwestern United States, northern Mexico, and parts of Central and South America. It causes pneumonia in Arizona and California, but it’s also present in parts of Utah, Nevada, Texas, and New Mexico. People who live in or travel through these areas are at risk for infection.

How Coccidioidomycosis affects your body

Once you inhale the fungus, it multiplies. This leads to the growth of the disease. It may take several weeks before you have symptoms. Because you breathe the fungus in, the disease affects your lungs. In a small number of people, it may spread outside of the lung to affect other parts of the body.

How serious is Coccidioidomycosis?

The disease is a common problem in Arizona and California, where it’s diagnosed more and more frequently. Travelers to these regions can get this disease. More than 100,000 cases were reported nationally between 1998 and 2011. Many people who have mild symptoms do not seek help. That is why mild cases are underreported.

  • Many people have few symptoms and do not require treatment.
  • Some people may develop more serious disease that requires treatment.
  • More serious symptoms may develop in anyone, but people with weakened immune systems are at higher risk.

Symptoms of Coccidioidomycosis

Many people have few or no symptoms. Symptoms that do appear include:

Symptoms that may seem like pneumonia include:

  • Joint aches;
  • Fatigue;
  • Rash; and
  • A disease that lasts for weeks rather than days.

A small number of people affected develop long-term disease that may affect lung function. It may also require extended treatment or even surgery. In some people with undiagnosed coccidioidomycosis, changes on chest X-rays or computed tomography (CT) scan images may look like lung cancer. Or, they may look like other long-lasting lung infections, such as tuberculosis. Fewer than 1% of people infected with coccidioidomycosis will develop disease outside the lungs.

What causes Coccidioidomycosis?

A fungus called Coccidioides causes coccidioidomycosis. This fungus is present in the soil in dry regions of the United States, Mexico, Central America, and South America. You can get this disease by breathing in fungal spores. The spores then multiply and cause symptoms of the disease.

What are risk factors for Coccidioidomycosis?

People living in or traveling to areas where this fungus lives are at risk for the disease. Exposure to dust storms or areas where soil is being disturbed, such as construction sites, puts you at a higher risk. Blacks and Filipinos seem to be at increased risk. People with weak immune systems are at increased risk of getting severe disease. They also have higher risk of the disease spreading through their body. People at high risk include:

  • People who have human immunodeficiency virus (HIV);
  • People taking immunosuppressant medication for autoimmune or rheumatologic diseases;
  • Solid-organ transplant recipients; and
  • People with diabetes.

Diagnosing Coccidioidomycosis

Coccidioidomycosis is diagnosed and treated differently from other causes of pneumonia. Early diagnosis of the disease is important.

This disease often goes unrecognized. It may require specific testing to make a diagnosis. Health care providers may not always consider coccidioidomycosis in people who are at risk for the disease. You may be misdiagnosed if you have traveled to the regions where the infection is most likely to occur but don’t develop symptoms until later. Health care providers outside these areas may not be familiar with the disease. For these reasons, diagnosis is often delayed and may require multiple visits to a health care provider.

How Coccidioidomycosis is diagnosed

Coccidioidomycosis is typically diagnosed using a blood test. This test examines your immune system’s response to the fungus. An abnormal blood test can help diagnose you.

The test may be negative early in the infection, so consider asking your health care provider for another test. You are diagnosed when your health care team finds the presence of the fungus. Your provider does this by examining infected tissue under a microscope or by growing it in a lab.

Other tests may include:

When should you see your health care provider?

Contact your health-care provider if you:

  • Live in an area where coccidioidomycosis occurs and develop these symptoms; or
  • Traveled to an area where coccidioidomycosis occurs and you develop symptoms.

Treating Coccidioidomycosis

Most people who have this disease do not need treatment. Those who have more severe symptoms may be treated with antifungal medications. Antifungal medications may also be used for those who have symptoms that last 8 weeks or longer.

However, if you have any of the following risk factors, you may receive treatment:

If you need treatment, you will likely take an antifungal medication by mouth. You may take this medication for a few months. The length of your treatment depends on your symptoms. It also depends on how well your infection responds to the medication.

If you have severe symptoms, you may need to be treated at the hospital. There, you will likely receive intravenous antifungal medication.

If you have a weak or compromised immune system, you may require medication for the rest of your life.

Rarely, surgery may be required to remove areas of infected or damaged lung.

Living with Coccidioidomycosis

Most people will not require treatment. The disease will go away on its own. Some people have symptoms that last for months after they are treated. And others may require long-term treatment.

If you have coccidioidomycosis but do not need medication, follow up with your provider for 1 year after your diagnosis. You are at a higher risk for developing worse symptoms during this year.

It is common for providers to refer people to specialists. This is especially common if primary care providers are not familiar with this disease.

All symptoms go away in most people who are diagnosed with this disease.
However, many people experience profound fatigue that lasts several months.

If you are diagnosed with coccidioidomycosis, you can participate in regular work, exercise, and diet routines if your symptoms allow.

Managing Coccidioidomycosis

Your health care provider may recommend the following during the first year after you are diagnosed.

  • Follow-up examinations
  • Follow-up blood testing and imaging, such as chest X-rays or CT scans

If you do not have long-term symptoms or show signs that the disease has affected other organs, you are not at risk again unless you develop a weakened immune system.


Disease information and resources about specialty centers and support may be found through the Valley Fever Center for Excellence.

The American Lung Association recommends that patients and caregivers join its Living with Lung Disease support community to connect with others facing this disease. You can also call the American Lung Association’s Lung Helpline at 1-800-LUNGUSA to talk to a trained lung professional. They can help answer your questions and connect you with additional support.

Questions to ask your health care provider

Make notes before your visit, and take along a trusted family member or friend. This can help you through the first appointment with your provider.

If you think you may have coccidioidomycosis, ask your provider:

  • What symptoms suggest coccidioidomycosis?
  • What tests help make the diagnosis?
  • If the first tests are negative, what follow-up, if any, is needed?

If you are diagnosed with coccidioidomycosis, ask your provider:

  • How do we know whether I need treatment?
  • How often do I need follow-up? What follow-up testing will I need?
  • How long do I need to be treated? What are the possible side effects?
  • What are the potential problems of not taking antifungal therapy, if it is prescribed?
  • What signs or symptoms of the disease should I watch for?
  • What are the long-term effects?

If you are traveling to the region where the fungus is and have an increased risk for getting a severe infection, ask your provider:

  • Am I at increased for getting coccidioidomycosis?
  • What, if any, protective measures should I take?
  • If I get sick, where should I go to get care?