What is skin fungus?
A fungus is a tiny organism, such as mold or mildew. Fungi are everywhere — in the air and water and on the human body. About half of fungi are harmful. If one of the harmful fungi lands on your skin, it can cause a fungal infection. You may develop a rash or feel itchy.
Who is at risk for developing a fungal rash?
Anyone can develop a fungal rash. Superficial infections of the skin and nails are cited as the most common form of infection, affecting up to 20-25% of the world’s population at any given time. For example, athlete’s foot often affects otherwise healthy people. You may have a higher risk for developing a skin rash if you:
- Have a weakened immune system (for example, if you take immunosuppressant medications, have a disease that weakens the immune system or are undergoing chemotherapy).
- Take long-term or high-dose antibiotics.
- Have excess weight.
- Have diabetes.
- Try a new skin care product.
- Experience incontinence (for example, babies getting diaper rashes).
- Sweat heavily.
- Are pregnant.
What does a fungal rash look like?
A fungal skin infection often looks bright red and can spread across a large area. A fungal skin rash may also have characteristics including:
- Color more intense at the border.
- Scale more intense at the border
- Smaller, more defined lesions (pustules) at the edges of the rash area.
Where does a fungal rash appear?
The rash can appear anywhere on the body, including the nails. It’s more common in areas with skin folds, such as the groin, buttocks or thighs.
What are different types of skin rashes?
The medical name for a fungal skin infection is tinea. Types of fungal infections include:
- Athlete’s foot (tinea pedis): The most common type of fungal infection, this condition often spreads when people walk barefoot in public bathrooms or locker rooms. The skin between your toes turns white and starts to peel. Athlete’s foot can also affect the soles (bottoms) of the feet.
- Nail fungus (onychomycosis): This infection is a common foot problem. It usually affects the toenails, which become yellow and thick and break easily.
- Jock itch (tinea cruris): A rash of the groin area, jock itch affects more men than women.
- Scalp ringworm (tinea capitis): This rash occurs mostly in children. It causes hair loss, but with the right treatment, the hair usually grows back.
- Ringworm (tinea corporis): This “catch-all” term is what healthcare providers call a rash that doesn’t fit into any other category. The rash often forms a ring shape.
Symptoms and Causes
What causes a fungal rash?
When your skin comes into contact with a harmful fungus, the infection can cause the rash to appear. For example, if you borrowed a pair of shoes from someone who had athlete’s foot, the fungus could come in contact with your foot and infect you. Rashes often pass from person to person or from animal to person by direct contact.
What are symptoms of a fungal rash?
A fungal rash is often red and itches or burns. You may have red, swollen bumps like pimples or scaly, flaky patches.
Diagnosis and Tests
How is a fungal rash diagnosed?
A healthcare provider may be able to diagnose a fungal rash by looking at it and asking about your symptoms. Many times, the diagnosis can be confirmed by examining scrapings of the scale under the microscope (KOH preparation). In some cases, you may need a fungal culture test to identify a specific fungus and help determine the best treatment for you.
During a fungal culture test, your provider may take a small sample of skin (biopsy) or fluid (aspiration). For severe infections, you may need a blood test.
Management and Treatment
How is skin fungus treated?
Treatment for skin fungus includes:
- Antifungal creams, many of which are available over-the-counter.
- Stronger prescription medications, which may work faster.
- Oral medicines, if the fungal infection is severe.
Can I treat a fungal rash at home?
It’s important for your healthcare provider to see the rash, especially if this is the first time the rash has appeared. Your provider can diagnose it and discuss the best course of action to treat it. Treating a fungal rash with an anti-itch cream that contains a steroid may make the infection worse and more difficult to treat.
How can I prevent a fungal rash?
In some people, fungal rashes tend to come back (recur) even after treatment. Recurring infections may be due to genetics — you may be more prone to developing these infections. These steps can help prevent a rash from recurring or developing in the first place:
Good foot hygiene
- Change your socks and wash your feet regularly. Avoid shoes made of plastic, which doesn’t breathe.
- Don’t walk barefoot, especially in places that may be wet, such as gym showers and locker rooms.
- When cutting your toenails, cut straight across the nail. If you have an ingrown toenail, you may need to see a podiatrist to care for it. And if you have a fungal nail infection, don’t use the same nail clippers on healthy nails and infected nails.
Proper medicine use
- If your healthcare provider prescribed a cream (or advised you to use an over-the-counter cream), use the medicine as long as directed. Even after you can no longer see the rash, the fungal infection may still be there, so keep applying the cream as long as your provider recommends.
- Your healthcare provider may recommend the same course of treatment for all the members of your family. Often, people living together can pass an infection back and forth. Treating everyone will help make sure the infection is truly gone.
- Talk to your healthcare provider about whether you should use an antifungal cream regularly on your feet and nails to help prevent infections.
- Using antifungal powder in your shoes every day may help prevent athlete’s foot.
Outlook / Prognosis
How long will I have the skin rash?
How long the treatment takes to work can differ from person to person. It usually takes a few days to a few weeks to clear up. The fungal infection may come back, however. Talk to your healthcare provider about steps you can take to prevent the infection from returning.
When should I see my doctor about a rash?
Most rashes are not serious. But it’s always a good idea to see your healthcare provider if you have skin changes. Your provider can recommend a course of treatment to help you feel better and diagnose any underlying conditions.
Call your healthcare provider or go to the emergency room if the rash:
- Is all over your body.
- Starts suddenly and spreads quickly.
- Is painful, blistered or infected.
- Happens along with a fever.
A note from Cleveland Clinic
Fungal skin rashes can be uncomfortable and itchy, but they are treatable. See your healthcare provider if you notice any rashes or changes in your skin. Typically, a course of antifungal creams (either prescription or over-the-counter) will clear up the rash and relieve the itchiness. Your healthcare provider can also discuss preventive steps to keep the rash from coming back.