Oral thrush occurs when a yeast infection develops on the inside of your mouth and on your tongue. This condition is also known as oral candidiasis, oropharyngeal candidiasis, or, simply, thrush.
The Candida albicans (C. albicans) fungus causes oral thrush. A small amount of this fungus normally lives in your mouth without causing harm. However, when the fungus begins to grow uncontrollably, an infection can develop in your mouth.
Oral thrush most often occurs in infants and toddlers. It causes white bumps to form on the inner cheeks and tongue. These growths usually go away once treatment is received.
Oral thrush is typically mild and rarely causes complications. However, the condition can be problematic for those with weakened immune systems.
In its initial stages, oral thrush may not cause any symptoms. However, as time passes and the fungus continues to grow, the following symptoms may develop:
- creamy white bumps on the tongue, inner cheeks, gums, or tonsils
- slight bleeding when the bumps are scraped
- pain at the site of the bumps
- angular cheilitis, or dry, cracked skin at the corners of the mouth
- difficulty swallowing
- a bad taste in the mouth
In infants, oral thrush may occasionally cause:
Babies with oral thrush can transmit it to their mothers during breastfeeding. Mothers and their infants can get caught in a cycle of transmission. If you’re breastfeeding and your breasts contract the fungus, you may experience:
Oral thrush occurs when the C. albicans fungus begins to grow out of control. Normally, the immune system uses “good” microorganisms to keep C. albicans and other “bad” microorganisms under control. When this balance is disrupted, harmful bacteria and fungi begin to multiply. This leads an infection to develop.
Oral thrush can occur when your immune system is weakened by certain medications that reduce the number of good microorganisms that would naturally prevent infection. Cancer treatments, including chemotherapy and radiation, can also damage or kill healthy cells. This makes you more susceptible to oral thrush and other infections.
Diabetes, another illness that affects your immune system, can contribute to oral thrush as well. If you have uncontrolled diabetes, you may have a high level of sugar in your saliva. One theory is that C. albicans can then use this extra sugar to fuel its growth in your mouth.
In newborns, oral thrush can be contracted at birth, though this is uncommon.
The same fungus that causes oral thrush also causes yeast infections, so pregnant women with a vaginal yeast infection can occasionally pass a yeast infection to their baby during delivery. Learn more about yeast infections during pregnancy.
Babies and toddlers have the highest risk of developing oral thrush. However, it can also affect people who have a weakened immune system. You may have a weak immune system and be more at risk for oral thrush if you:
- have diabetes, anemia, or HIV
- have an illness that causes dry mouth
- take antibiotics or corticosteroids
- use chemotherapy, radiation, or drugs to treat cancer
- wear dentures
- smoke cigarettes
- recently had an organ transplant, which increases the risk of fungal infection
Your doctor will probably be able to diagnose oral thrush simply by examining your mouth and tongue for the characteristic white bumps.
In some cases, your doctor may take a biopsy to confirm the diagnosis. A biopsy involves scraping off a very small portion of a bump in the mouth. The sample is then sent to a laboratory, where it’ll be tested for the presence of C. albicans.
During a throat swab culture, your doctor will use a cotton swab to take a tissue sample from the back of your throat. The sample will then be sent to a laboratory for analysis.
Endoscopy involves the use of a thin tube with an attached light and camera. This is called an endoscope. Your doctor will insert the endoscope through your mouth and into your esophagus to examine the affected area. They may also remove a sample of tissue for inspection.
Treatment for oral thrush varies depending on your age and overall health. The purpose of treatment is to prevent the growth and spread of the fungus.
Once treatment begins, oral thrush usually goes away within a couple of weeks. However, oral thrush may return again in the future. A complete cure is more likely if you have a healthy immune system and are free of other diseases.
If you have recurring cases of oral thrush and are otherwise healthy, your doctor will evaluate you for an underlying condition that’s causing the thrush.
The following medical treatments may be used for oral thrush.
- Fluconazole (Diflucan). Fluconazole is an oral antifungal medication.
- Clotrimazole (Mycelex Troche). Your doctor will prescribe the lozenge form of this antifungal medication. The medication is left in the mouth until it dissolves.
- Nystatin (Nystop, Nyata). This is an antifungal mouthwash that you swish around in your mouth and then swallow. In an infant, it’s swabbed in the mouth.
- Itraconazole (Sporanox). This oral antifungal is used for people who are resistant to initial treatments or who have HIV.
- Amphotericin B (AmBisome, Fungizone). This drug is used to treat severe cases.
To treat oral thrush at home, be sure to:
- Brush your teeth with a soft toothbrush to avoid scraping the lesions. Replace the toothbrush at the end of treatment.
- Properly clean your dentures.
- Don’t use mouthwashes or mouth sprays aside from prescribed ones.
- Maintain appropriate blood sugar levels if you have diabetes.
You can also try the following:
- Use a saltwater mixture to rinse your mouth. To make a saltwater rinse, mix 1/4 to 1/2 teaspoon of salt in 8 ounces of warm water.
- Eat unsweetened yogurt to help restore and maintain healthy levels of good bacteria.
Treatments for mothers and breastfeeding infants
When a breastfeeding infant has oral thrush, both the mother and infant should be treated to prevent a cycle of retransmission. Treatment in these cases may include the following:
- Use an antifungal medication for the baby and an antifungal cream for the mother’s breasts, such as terbinafine (Lamisil) or clotrimazole (Lotrimin). Wipe the cream off the breast before feeding your baby to prevent it from getting in their mouth.
- Rinse pacifiers, bottle nipples, and all pieces of a breast pump in a solution of half water and half vinegar. Allow the items to air-dry. You can also wash these in hot water in the dishwasher, and allow to dry in the sun.
- Use nursing pads to prevent the fungus from spreading to clothes.
Oral thrush rarely causes complications in people with healthy immune systems.
People whose immune systems are weakened by certain diseases or medical treatments are the most likely to experience complications. If you have a weak immune system, the fungus may enter your bloodstream and spread throughout your body. This can eventually cause problems in various body structures, including the brain, heart, and liver.
Infants who develop oral thrush also may get a severe diaper rash.
You can reduce your risk for oral thrush by following these simple routines:
- Practice good oral hygiene by brushing your teeth. Also floss daily. This is especially important if you have diabetes or wear dentures.
- Rinse out your mouth after using a corticosteroid inhaler.
- Add yogurt to your diet whenever you take prescribed antibiotics.
- Promptly treat a vaginal yeast infection, especially if you’re pregnant.