Understanding fungus in the mouth and throat

Your mouth and throat normally contain millions of tiny organisms. These include bacteria and yeasts. Many of these don't cause any problems. In fact, they may help fight disease.

Yeasts are a type of fungus. A type of yeast called Candida normally lives on the membranes of your mouth and throat. It also lives in the digestive tract and on your skin. Usually, this yeast grows only in small amounts and is harmless. But in some cases, Candida can grow out of control and cause thrush. Thrush is related to other kinds of Candida infections that can occur at other parts of the body. Thrush refers to an infection of only the mouth and throat.

What causes thrush?

Thrush happens when something lets too much Candida grow inside your mouth and throat. Certain things that change the normal balance of organisms in the mouth can lead to thrush. One example is antibiotic medicine. This medicine may kill some of the normal bacteria in your mouth. Candida can then grow freely. People on antibiotics have an increased risk for thrush.

You have a higher risk for thrush if you:

• Wear dentures

• Are getting chemotherapy or radiation therapy

• Have diabetes

• Have a transplanted organ

• Use corticosteroids, including inhaled corticosteroids for lung disease

• Have a weak immune system, such as from HIV infection or AIDS

• Are an older adult

Symptoms of thrush

Symptoms of thrush can include:

• A dry, cottony feeling in your mouth

• Cracking at the corners of the mouth

• Loss of taste

• Pain while eating or swallowing

• White patches on the tongue and around the sides of the mouth

Diagnosing thrush

Your healthcare provider will ask about your medical history and your symptoms. They will look closely at your mouth and throat. White or red patches will be found and may be scraped with a tongue depressor. A sample may be looked at under a microscope or sent to a lab to test. Most cases are confirmed just by their appearance; testing can sometimes help to confirm thrush.

If you have thrush, you may also have esophageal candidiasis. This is more common in people who have AIDS or a weak immune system for another reason. Your healthcare provider may diagnose this based on your symptoms and may check for this condition with an upper endoscopy. This is a procedure to examine the digestive tract using a tube with a light and a camera. During this procedure, a tissue sample may be taken to test.

Treatment for thrush

Thrush is usually treated with antifungal medicine. For mild cases, the medicine is often applied directly in your mouth and throat. This may be in the form of a “swish and swallow” medicine or an antifungal lozenge to suck on and dissolve in your mouth.

In more extensive cases, or if you have a weakened immune system, you may instead be treated with an antifungal pill. This can be a stronger treatment than a "swish and swallow" or lozenge antifungal. Or you may need medicine through an IV (intravenous) line. These treatments depend on how severe your infection is and what other health conditions you have.

If you are at high risk for thrush, you may need to keep taking oral antifungal medicine. This is to help prevent thrush in the future.

What happens if you don’t get treated for thrush?

If untreated, the Candida may make it difficult to eat or drink. Or it can spread to the esophagus and, rarely, to other parts your body.

Preventing thrush

You may be able to help prevent some cases of thrush. Make sure to:

• Practice good oral hygiene.

• Clean your dentures regularly as instructed. Make sure they fit you correctly.

• After using a corticosteroid inhaler, rinse out your mouth with water or mouthwash.

• Take antibiotics only when clearly needed. Follow your healthcare provider's specific instructions.

• Get treated for health problems that increase your risk for thrush, such as diabetes or HIV.

When to call the healthcare provider

Call your healthcare provider right away if you have any of these:

• Cottony feeling in your mouth

• Loss of taste

• Pain while eating or swallowing

• White patches or plaques on your tongue or inside your mouth