Valley Fever in Arizona
What Every Arizona Resident Should Know About This Desert Fungus
Valley fever is a fungal lung infection caused by a desert fungus that lives naturally in Arizona’s soil. Because its symptoms closely resemble the flu or a bad cold, it is frequently misdiagnosed, leaving many patients without proper treatment for weeks or months. At Carefree Allergy, we help Arizona patients identify whether respiratory symptoms could be linked to Valley fever or an underlying allergy condition and connect them with the right care.
What Is Valley Fever?
Valley fever is the common name for coccidioidomycosis, a lung infection caused by inhaling spores of the fungus Coccidioides. This desert fungus lives in the dry soil of the American Southwest, and Arizona – particularly Maricopa, Pima, and Pinal counties – is one of the highest-risk regions in the country.
The fungal spores become airborne when soil is disturbed by winds, construction, farming, and other activities. Once inhaled, the spores can settle into the lungs and cause an infection ranging from mild and self-resolving to severe and chronic.
In Arizona, the highest prevalence of infections occurs from June through July and from October through November, though exposure is possible any time the desert soil is disturbed. Haboobs, dust storms, and high-wind events that are common across the Phoenix valley create ideal conditions for spores to travel through the air and be inhaled without warning.
Valley Fever Symptoms
Symptoms of Valley fever may appear between one and three weeks after exposure and can be mild to severe, lasting from weeks to months. Many people experience no symptoms at all and recover without ever knowing they were infected.
When symptoms do appear, they are often mistaken for the flu, a sinus infection, or even COVID-19. Common Valley fever symptoms include:
Fatigue and general weakness
Fever and cough
Shortness of breath
Headache
Night sweats
Muscle and joint aches
Chest pain
Loss of appetite or unintentional weight loss
Valley Fever Rash
Valley fever can cause rashes that look several different ways. A common presentation is painful or tender, slightly elevated red nodules or bumps that may change color to bluish or brown and often occur on the legs, but may occur on the chest, arms, and back. This rash is sometimes referred to as “desert rheumatism” when accompanied by joint pain and fever.
In rare cases, Valley fever can become disseminated disease, where the infection spreads to other areas of the body including the central nervous system, bones, joints, and skin. Those at higher risk for severe illness include people over 60, those with weakened immune systems, pregnant women, and people with diabetes.
How to Prevent Valley Fever
There is currently no vaccine for Valley fever. Avoiding activities associated with dust and airborne dirt of native desert soil is recommended, but it is not a certain means of prevention, as the dust may or may not contain Coccidioides spores.
That said, there are practical steps Arizona residents and visitors can take to reduce exposure:
Stay inside during dust storms
When a haboob hits, close your windows and set your air conditioning to recirculate indoor air to avoid pulling contaminated air inside.
Wear an N95 mask in dusty environments
If you work in construction, landscaping, or any setting with disturbed desert soil, an N95 respirator is your most effective barrier against inhaling airborne spores.
Wet the soil before digging
Dampening desert soil before gardening, excavating, or doing yard work significantly reduces the amount of dust and spores that become airborne.
Limit high-risk outdoor activities on dry, windy days
Off-road driving, archaeological digging, and farming stir up large amounts of desert soil. Avoid or minimize these activities when wind and dry conditions increase spore exposure.
Lindsey Forstie, FNP and the Journey That Shaped Her Approach to Allergy Care
Lindsey’s journey into allergy and asthma care began long before her medical training. As a child, she struggled with undiagnosed asthma. Physical activity meant chest tightness, headaches, and falling behind despite her effort. For years, she believed her limitations were personal rather than medical. It was not until a school nurse recognized the signs of asthma and proper treatment began that everything changed. Breathing improved, confidence returned, and the boundaries she had quietly accepted began to disappear.
That experience shaped the direction of her career. Lindsey became a nurse, then a board certified family nurse practitioner specializing in allergy and immunology. She founded Carefree Allergy with a clear mission: no one should have to live within unnecessary limits caused by untreated asthma or uncontrolled allergies.
Board-Certified Provider
Licensed in Arizona
10+ Years Experience
Telehealth Statewide
We Can Help You Get Answers
Symptoms like a persistent cough, fatigue, and shortness of breath can point to many different conditions, including allergies, asthma, and Valley fever. If you have been living in Arizona and your symptoms are not resolving as expected, getting properly evaluated is the most important next step.
At Carefree Allergy, we evaluate respiratory and immune symptoms in children and adults across Arizona, helping patients understand whether environmental allergies, airway inflammation, or other conditions are driving their symptoms. We offer same-day testing and telehealth visits statewide.
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What Our Patients Say
Real stories from real people who found relief
SMSarah Mitchell
Arizona
Seasonal Allergies
★★★★★
After years of struggling with allergies, I finally found relief! The allergy drops are so convenient, and I’m no longer dependent on daily medications.
JRJames Rodriguez
Arizona
Food Allergies
★★★★★
The testing was quick and thorough. Knowing exactly what I’m allergic to has completely changed how I manage my symptoms. Highly recommend!
ECEmily Chen
Arizona
Asthma & Allergies
★★★★★
Lindsey is amazing! She took the time to understand my unique situation and created a treatment plan that actually works. I can breathe easy again!
Common Questions
Can you die from Valley fever?
Most people recover fully from Valley fever without serious complications. However, in a small percentage of cases, particularly in those with weakened immune systems, the infection can spread beyond the lungs to the brain, bones, and other organs. When coccidioidomycosis spreads to the brain, it can develop into coccidioidal meningitis, a life-threatening condition that causes neurological symptoms including vision and hearing changes, headaches, and neck stiffness. Prompt diagnosis and treatment significantly improve outcomes for high-risk patients.
How do you test for Valley fever?
Blood tests are the most common way to diagnose Valley fever. A blood sample is sent to a lab to look for signs of Coccidioides, like antibodies or antigens. Imaging tests such as chest X-rays or CT scans may also be used to assess the lungs. In some cases, a biopsy or sputum sample may be collected. Because Valley fever symptoms overlap with many other conditions, it is important to tell your provider if you live in or have recently spent time in Arizona or another endemic region.
How common is Valley fever?
About 15,000 cases of Valley fever are reported each year, with the greatest number of cases diagnosed in California and Arizona. However, the true number of infections is believed to be far higher, since many cases are asymptomatic or misdiagnosed. In south-central Arizona, Valley fever has been found to account for a significant portion of community-acquired pneumonia cases.
How common is Valley fever? What are the symptoms of Valley fever?
Valley fever symptoms typically appear one to three weeks after exposure and resemble the flu. The most common symptoms are fatigue, fever, cough, shortness of breath, headache, night sweats, and muscle or joint aches. Some patients also develop a skin rash of red, tender bumps – most often on the legs. Symptoms can last from a few weeks to several months, and in chronic cases, may persist much longer.
How do you get Valley fever?
Breathing in spores of the fungi Coccidioides immitis and Coccidioides posadasii causes Valley fever. These fungi live in the soil in parts of Arizona, California, Nevada, Utah, New Mexico, Texas, and Washington, as well as in northern Mexico and Central and South America. Exposure is most likely during activities that disturb the soil, including construction work, landscaping, hiking, off-road driving, and farming, especially during dry, windy conditions common across the Phoenix valley and greater Arizona desert.
What foods should I avoid with Valley fever?
There is no specific medically established diet for Valley fever, but what you eat can support or slow your recovery. It is best to limit alcohol along with excess sugar, processed foods, caffeine, and heavy dairy, all of which can promote inflammation or worsen symptoms. Focus on staying well-hydrated and eating whole, nutrient-dense foods. If you are on antifungal medication, ask your provider about any specific food or supplement interactions.
Is Valley Fever Contagious?
No. Valley fever is not contagious and cannot be spread from person to person or from animal to person. You can only become infected by breathing in fungal spores directly from the soil or dust. This means that household members, coworkers, and caregivers are not at risk of catching it from an infected person.
In extremely rare cases, people can get the infection from other sources, such as an organ transplant if the donor had Valley fever, or contact with contaminated objects. Outside of those rare exceptions, person-to-person transmission does not occur.