Coccidioidomycosis is an infection known more commonly as “valley fever.” It’s caused by a fungus called Coccidioides immitis or Coccidioides posadasii. You can get the infection by inhaling the spores of the fungus. Lesions are one of many possible symptoms of infection by Coccidioides fungi.
An infection by Coccidioides immitis begins in the lungs, but it can travel to other parts of your body. When the fungus affects your skin, it causes rashes and lesions. Skin lesions are a sign that the fungal infection has become widespread (or disseminated) in your body.
Some people will recover from the infection with no treatment as the majority of people infected with valley fever have minimal symptoms. A minority of people will develop very severe and life-threatening infections. Coccidioidomycosis is most commonly contracted in desert regions in the southwestern United States, and in Central and South America. The name valley fever comes from the fact that this ailment was first uncovered in the San Joaquin Valley of northern California.
If you contract valley fever, you may experience lesions or rashes as a symptom. There are two stages of the disease. You may experience only the first stage and recover before reaching the more serious second stage. However, in a majority of people, minimal or no symptoms are seen.
Early infection may cause mild or severe symptoms, similar to those of the flu. These may include:
- joint pain
- muscle ache
During the initial infection, the fungus may infect your lungs and you may experience skin lesions. These can include erythema nodosum or erythema multiforme. These lesions often look like strange bruises. These types of skin rashes are usually not serious and they often go away when the valley fever is treated.
The rashes that appear during primary infection are most likely caused by your immune system reacting to the fungal infection. They are not caused by the fungus itself.
If the infection isn’t treated and is allowed to spread, the disease has become disseminated, the second stage of the infection. In this stage of valley fever, the infection has spread from your lungs to other parts of your body, including your skin.
Dissemination of the infection is very serious. The infection may spread to your bones, brain, and cause further lung and skin manifestations. The lesions that you may experience during this second stage of infection are much more severe. You may experience any of the following lesion types:
- papule: a raised spot on your skin that is solid and less than a centimeter across
- nodule: the same as a papule, but larger than a centimeter in width
- pustule: a pus-filled lesion that is inflamed and small in size
- abscess: a larger pus-filled lesion
These lesions will contain the fungus. They are evidence of a widespread infection.
Coccidioides immitis and Coccidioides posadasii are commonly found in certain regions of California, New Mexico, Arizona, Nevada, Utah, and Texas. They are also known to be found in Northern Mexico and certain parts of Central and South America. Valley fever is spread by inhalation of fungal spores when it is kicked up during farming or construction, for example.
Many healthy people who become infected will not experience any symptoms. Some may have mild symptoms that clear up before the infection becomes widespread.
If you get infected, the disease is much more likely to progress to the disseminated stage if your immune system is compromised, such as with HIV or cancer. You should talk to a doctor as soon as possible if you have an impaired immune system and think you have been infected with valley fever. According to the U.S. Centers for Disease Control and Prevention (CDC), people who are at risk of developing a severe case of valley fever include:
- people with HIV/AIDS
- pregnant women
- anyone who has had an organ transplant
- people with diabetes
Because the symptoms of valley fever can be so varied from person to person, your doctor may not be able to diagnose it on symptoms alone. To pinpoint the infection, you must have a test that identifies the Coccidioides immitis or Coccidioides posadasii fungus in your body.
A blood test can detect antibodies specific to the fungus. Your doctor may also want to take a sample of your sputum, which is the thick fluid secreted in your airways if you get infected. The fungus can be seen in the sample.
Antifungal medications are used to treat the skin lesions associated with coccidioidomycosis.
In the primary stage of infection, the lesions may clear up without any treatment. If treatment is needed with antifungal medications, close follow-up is recommended every couple of months.
In the dissemination phase, treatment is necessary. Antifungal medication can be given topically (applied to the skin), intravenously (injected), or in pill form. If you have a suppressed or weakened immune system, you may need long-term treatment. You may also need antibiotics to treat any infections in the broken skin of the lesions.
The outlook for the lesions associated with valley fever depends upon the stage of infection and the state of your immune system. If you have a primary infection and are healthy, the outlook is excellent. Symptoms will usually disappear within two to six weeks. If you have a compromised immune system or a disseminated infection, recovery can take up to a year and is less certain. In rare cases, valley fever can be fatal.
Because you become infected with valley fever by breathing in the spores of the fungus, it’s a difficult disease to prevent. Those who are at greater risk of having a more severe case of valley fever should avoid living in areas where valley fever is more prevalent. The CDC recommends taking the following steps to help prevent valley fever:
- avoid dusty areas like construction sites
- avoid activities that can kick up a lot of dirt or dust, such as gardening
- stay inside during dust storms
- wear a respirator if your area is particularly dusty
- use a HEPA air purifier in your home
- clean any cuts or scrapes well and keep them bandaged to prevent dirt or dust from causing a skin infection
Remember that the majority of people infected with valley fever experience little or no symptoms. Taking these steps is most helpful for those who have impaired immune systems or at greater risk of developing a more severe case. Talk to your doctor if you live in or will be visiting a region that has a higher risk of valley fever and have any concerns.