Valley fever is a fungal infection caused by coccidioides (kok-sid-e-OY-deze) organisms. It can cause fever, chest pain and coughing, among other signs and symptoms.
Two species of coccidioides fungi cause valley fever. These fungi are commonly found in the soil in specific areas and can be stirred into the air by anything that disrupts the soil, such as farming, construction and wind. The fungi can then be breathed into the lungs and cause valley fever, also known as acute coccidioidomycosis (kok-sid-e-oy-doh-my-KOH-sis).
Mild cases of valley fever usually resolve on their own. In more severe cases, doctors prescribe antifungal medications that can treat the underlying infection.
Valley fever is the initial form of coccidioidomycosis infection. This initial, acute illness can develop into more serious disease, including chronic and disseminated coccidioidomycosis.
Acute coccidioidomycosis (valley fever)
The rash that sometimes accompanies valley fever is made up of painful red bumps that may later turn brown. The rash mainly appears on your lower legs, but sometimes on your chest, arms and back. Others may have a raised red rash with blisters or eruptions that look like pimples.
If you don't become ill from valley fever, you may learn that you've been infected only when you later have a positive skin or blood test or when small areas of residual infection (nodules) in the lungs show up on a routine chest X-ray. Although the nodules typically don't cause problems, they can look like cancer on X-ray.
If you do develop symptoms, especially severe ones, the course of the disease is highly variable. It can take months to fully recover, and fatigue and joint aches can last even longer. The severity of the disease depends on several factors, including your overall health and the number of fungus spores you inhale.
The signs and symptoms of disseminated disease depend on which parts of your body are affected and may include:
When to see a doctor
Seek medical care if you are in a high-risk group and develop the signs and symptoms of valley fever, especially if you:
Be sure to tell your doctor if you've traveled to a place where valley fever is endemic and you have symptoms. More and more, people who spend a few days golfing or hiking in Arizona return home with valley fever but are never tested for the disease.
The fungi that cause valley fever — Coccidioides immitis or Coccidioides posadasii — thrive in the arid desert soils of southern Arizona, Nevada, northern Mexico and California's San Joaquin Valley. They're also endemic to New Mexico, Texas, and parts of Central and South America — areas with mild winters and arid summers.
Like many other fungi, coccidioides species have a complex life cycle. In the soil, they grow as a mold with long filaments that break off into airborne spores when the soil is disturbed. The spores are extremely small, can be carried hundreds of miles by the wind and are highly contagious. Once inside the lungs, the spores reproduce, perpetuating the cycle of the disease.
More than half of those who inhale coccidioides fungi have few, if any, problems. But some, especially pregnant women, people with weakened immune systems — such as those living with HIV/AIDS — and those of Filipino, Hispanic, African, Native American or Asian descent are at risk of developing a more severe form of coccidioidomycosis.
Complications of coccidioidomycosis may include:
Preparing for your appointment
Make an appointment with your doctor if you develop signs or symptoms of valley fever and are in or have recently returned from a region where this condition is common.
Here's some information to help you get ready and know what to expect from your doctor.
Information to gather in advance
The list below suggests questions to raise with your doctor about valley fever. Don't hesitate to ask more questions during your appointment.
What to expect from your doctor
Tests and diagnosis
Valley fever is difficult to diagnose solely on the basis of signs and symptoms, which are usually vague and nonspecific, or on a chest X-ray, which can't distinguish valley fever from other lung diseases. Instead, a definitive diagnosis depends on finding evidence of coccidioides organisms in tissue, blood or other body secretions. For that reason, you're likely to have one or more of the following tests:
Treatments and drugs
In general, the antifungal drugs fluconazole (Diflucan) or itraconazole (Sporanox, Onmel) are used for all but the most serious forms of coccidioidomycosis disease.
All antifungals can have serious side effects. However, these side effects usually go away once the medication is stopped. The most common side effects of fluconazole and itraconazole are nausea, vomiting, abdominal pain and diarrhea.
More serious infection may be treated initially with an intravenous antifungal medication such as amphotericin B (Abelcet, Amphotec, others).
These medications control the fungus, but sometimes don't destroy it, and relapses may occur. For many people, a single bout of valley fever results in lifelong immunity, but the disease can be reactivated, or you can be reinfected if your immune system is significantly weakened.
If you live in or visit areas where valley fever is common, take common-sense precautions, especially during the summer months when the chance of infection is highest. Consider wearing a mask, staying inside during dust storms, wetting the soil before digging, and keeping doors and windows tightly closed.
Last Updated: 2012-07-06
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