Oral thrush — also called oral candidiasis (kan-dih-DIE-uh-sis) — is a condition in which the fungus Candida albicans accumulates on the lining of your mouth. Candida is a normal organism in your mouth, but sometimes it can overgrow and cause symptoms.
Oral thrush causes creamy white lesions, usually on your tongue or inner cheeks. Sometimes oral thrush may spread to the roof of your mouth, your gums or tonsils, or the back of your throat.
Although oral thrush can affect anyone, it's more likely to occur in babies and older adults because they have reduced immunity; in other people with suppressed immune systems or certain health conditions; or people who take certain medications. Oral thrush is a minor problem if you're healthy, but if you have a weakened immune system, symptoms may be more severe and difficult to control.
Symptoms
Children and adults
Initially, you may not even notice symptoms of oral thrush. Signs and symptoms may include:
Creamy white lesions on your tongue, inner cheeks, and sometimes on the roof of your mouth, gums and tonsils
Slightly raised lesions with a cottage cheese-like appearance
Redness, burning or soreness that may be severe enough to cause difficulty eating or swallowing
Slight bleeding if the lesions are rubbed or scraped
Cracking and redness at the corners of your mouth
A cottony feeling in your mouth
Loss of taste
Redness, irritation and pain under dentures (denture stomatitis)
In severe cases, usually related to cancer or a weakened immune system from HIV/AIDS, the lesions may spread downward into your esophagus — the long, muscular tube stretching from the back of your mouth to your stomach (Candida esophagitis). If this occurs, you may experience difficulty swallowing and pain or feel as if food is getting stuck in your throat.
Infants and breast-feeding mothers
In addition to the distinctive white mouth lesions, infants may have trouble feeding or be fussy and irritable. They can pass the infection to their mothers during breast-feeding. The infection may then pass back and forth between the mother's breasts and the baby's mouth.
Women whose breasts are infected with candida may experience these signs and symptoms:
Unusually red, sensitive, cracked or itchy nipples
Shiny or flaky skin on the darker, circular area around the nipple (areola)
Unusual pain during nursing or painful nipples between feedings
Stabbing pains deep within the breast
When to see a doctor
If you or your child develops white lesions inside the mouth, see your doctor or dentist.
Thrush is uncommon in healthy older children, teenagers and adults, so if thrush develops, see your doctor to determine if further evaluation is needed to check for an underlying medical condition or other cause.
Causes
Normally, your immune system works to repel harmful invading organisms, such as viruses, bacteria and fungi, while maintaining a balance between "good" and "bad" microbes that normally inhabit your body. But sometimes these protective mechanisms fail, increasing the number of candida fungus and allowing an oral thrush infection to take hold.
The most common type of candida fungus is Candida albicans. Several factors, such as a weakened immune system, can increase your risk of oral thrush.
Risk factors
You may have an increased risk of oral thrush infection if any of these issues apply:
Weakened immunity. Oral thrush is more likely to occur in infants and older adults due to reduced immunity. Some medical conditions and treatments can suppress your immune system, such as cancer and its treatments, organ transplantation and required drugs that suppress the immune system, and HIV/AIDS.
Diabetes. If you have untreated diabetes or the disease isn't well-controlled, your saliva may contain large amounts of sugar, which encourages the growth of candida.
Vaginal yeast infections. Vaginal yeast infections are caused by the same fungus that causes oral thrush. You can pass the infection to your baby.
Medications. Drugs such as prednisone, inhaled corticosteroids, or antibiotics that disturb the natural balance of microorganisms in your body can increase your risk of oral thrush.
Other oral conditions. Wearing dentures, especially upper dentures, or having conditions that cause dry mouth can increase the risk of oral thrush.
Complications
Oral thrush is seldom a problem for healthy children and adults.
For people with lowered immunity, such as from cancer treatment or HIV/AIDS, thrush can be more serious. Untreated oral thrush can lead to more-serious systemic candida infections. If you have a weakened immune system, thrush may spread to your esophagus or other parts of your body.
Prevention
These measures may help reduce your risk of developing candida infections:
Rinse your mouth. If you need to use a corticosteroid inhaler, be sure to rinse your mouth with water or brush your teeth after taking your medication.
Brush your teeth at least twice a day and floss daily or as often as your dentist recommends.
Check your dentures. Remove your dentures at night. Make sure dentures fit properly and don't cause irritation. Clean your dentures daily. Ask your dentist for the best way to clean your type of dentures.
See your dentist regularly, especially if you have diabetes or wear dentures. Ask your dentist how often you need to be seen.
Watch what you eat. Try limiting the amount of sugar-containing foods you eat. These may encourage the growth of candida.
Maintain good blood sugar control if you have diabetes. Well-controlled blood sugar can reduce the amount of sugar in your saliva, discouraging the growth of candida.
Treat a vaginal yeast infection as soon as possible.
Treat dry mouth. Ask your doctor about ways to avoid or treat your dry mouth.
Diagnosis
Diagnosis of thrush depends on the location and identifying whether there is an underlying cause.
If thrush is limited to your mouth
To diagnose oral thrush, your doctor or dentist may:
Examine your mouth to look at the lesions
Take a small scraping of the lesions to examine under a microscope
If needed, do a physical exam and certain blood tests to identify any possible underlying medical condition that may be the cause of oral thrush
If thrush is in your esophagus
To help diagnose thrush in your esophagus, your doctor may recommend any or all of these:
Biopsy. The tissue sample is cultured on a special medium to help determine which bacteria or fungi, if any, are causing your symptoms.
Endoscopic exam. In this procedure, your doctor examines your esophagus, stomach and upper part of your small intestine (duodenum) using a lighted, flexible tube with a camera on the tip (endoscope).
Physical exam. If needed, a physical exam and certain blood tests may be done to try to identify any possible underlying medical condition that could cause thrush in the esophagus.
Treatment
The goal of any oral thrush treatment is to stop the rapid spread of the fungus, but the best approach may depend on your age, your overall health and the cause of the infection. Eliminating underlying causes, when possible, can prevent recurrence.
Healthy adults and children. Your doctor may recommend antifungal medication. This comes in several forms, including lozenges, tablets, or a liquid that you swish in your mouth and then swallow. If these topical medications are not effective, medication may be given that works throughout your body.
Infants and nursing mothers. If you're breast-feeding and your infant has oral thrush, you and your baby could pass the infection back and forth. Your doctor may prescribe a mild antifungal medication for your baby and an antifungal cream for your breasts.
Adults with weakened immune systems. Most often your doctor will recommend antifungal medication.
Thrush may return even after it's been treated if the underlying cause, such as poorly disinfected dentures or inhaled steroid use, isn't addressed.
