Oral thrush is a condition in which the fungus Candida albicans grows out of control. Like most healthy people, you probably have small amounts of the fungus in your mouth and digestive tract and on your skin. You can't see the fungus and normally won't know it's there — it usually doesn't cause problems because normal bacteria (flora) in your body keep its growth in check. But when this balance is disturbed — by medications or illness — Candida can grow out of control, leading to problems such as diaper rash and vaginal yeast infections as well as oral thrush.
Oral thrush causes creamy white lesions, usually on your tongue or inner cheeks. The lesions can be painful and may bleed slightly when you scrape them or brush your teeth. Sometimes oral thrush may spread to the roof of your mouth, your gums, tonsils or the back of your throat.
Although oral thrush can affect anyone, it occurs most often in babies and toddlers, older adults, and people whose immune systems have been compromised by illness or medications. Oral thrush is a minor problem for healthy children and adults, but for those with weakened immune systems, symptoms of oral thrush may be more severe, widespread and difficult to control.
Microorganisms such as viruses, bacteria and fungi are everywhere, including in and on your own body. In general, the relationship between you and the microorganisms in your body is mutually beneficial. You provide nutrition, protection and transportation for them, while they stimulate your immune system, synthesize essential vitamins, and help protect against harmful viruses and bacteria.
But your relationship to microorganisms in the world at large is more complex. Some microbes are highly beneficial, whereas others — such as those that cause malaria and meningitis — can be deadly. For that reason, your immune system works to repel harmful invading organisms while maintaining a balance between "good" and "bad" microbes that normally inhabit your body.
But sometimes these protective mechanisms fail. Oral thrush and other Candida infections occur when your immune system is weakened by disease or drugs such as prednisone, or when antibiotics disturb the natural balance of microorganisms in your body.
These illnesses may make you more susceptible to oral thrush infection :
- Chronic mucocutaneous candidiasis. Usually affecting children younger than age 3, this group of rare disorders is marked by a chronic Candida infection of the mouth and fingernails and of the skin on the scalp, trunk, hands and feet. Scaly, crusted lumps known as granulomas also may develop in the mouth or on the nails and skin. Adults occasionally develop the disorder — usually as a result of a tumor on the thymus gland (thyoma).
- HIV/AIDS. The human immunodeficiency virus (HIV) — the virus that causes AIDS — damages or destroys the cells of your immune system, making you more susceptible to opportunistic infections your body would normally resist. One of these opportunistic infections is oral thrush. Thrush is rare in the early stage of AIDS, usually appearing only when counts of helper T cells — one of the key cells in the immune system — fall below 350. Although oral thrush is the least serious of the fungal infections that can affect people with HIV, it may be an indication that HIV is worsening. Candida esophagitis, which occurs when thrush spreads to the esophagus, generally develops when T cell counts are 200 or less and is considered an AIDS-defining illness — an opportunistic illness that indicates a person with HIV is developing AIDS.
- Cancer. If you're dealing with cancer, your immune system is likely to be weakened both from the disease and from treatments such as chemotherapy and radiation, increasing the risk of Candida infections such as oral thrush.
- Diabetes mellitus. If you don't know you have 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. It's estimated that three out of every four women will have a vaginal yeast infection (Candida vulvovaginitis) at least once before menopause. Vaginal yeast infections are caused by the same fungus that causes oral thrush. Although a yeast infection isn't dangerous, a pregnant woman can pass the fungus to her baby during delivery. As a result, her newborn may develop oral thrush within the first several weeks after birth. Up to 5 percent of healthy newborns with oral thrush are infected through mother-to-child transmission.
- Dry mouth (xerostomia). This occurs when the salivary glands don't produce enough moisture. Dry mouth disrupts the balance of normal microorganisms in your mouth, increasing your risk of oral thrush. Although not itself a disease, dry mouth can be a symptom of certain illnesses, including Sjogren's syndrome — an autoimmune disease that causes an extremely dry mouth and eyes. Bone marrow transplants, stress or anxiety, depression, and certain nutritional deficiencies also can cause a dry mouth. So can chemotherapy, radiation to the head and neck area and hundreds of medications — especially antidepressants, pain and high blood pressure drugs, tranquilizers, diuretics and antihistamines.
Risk Factor :
Anyone can develop oral thrush, but the infection is especially common in infants and toddlers whose immune systems aren't fully developed. In addition, babies can pass the infection to their mothers during breast-feeding.
You're also more likely to develop oral thrush if you :
- Are an older adult
- Have a compromised immune system
- Use corticosteroids, antibiotics or birth control pills
- Wear dentures
Oral thrush usually produces creamy white lesions on your tongue and inner cheeks and sometimes on the roof of your mouth, gums and tonsils. The lesions, which resemble cottage cheese, can be painful and may bleed slightly when rubbed or scraped. Although signs and symptoms often develop suddenly, they may persist for a long period of time.
In severe cases, the lesions may spread downward into your esophagus — the long, muscular tube stretching from the back of your mouth to your stomach (Candidaesophagitis). Signs and symptoms of Candida esophagitis may include :
- Pain or difficulty swallowing
- A sensation of food sticking in your throat or the middle of your chest
- Possible fever if the infection spreads beyond your esophagus
Symptoms in infants and breast-feeding mothers
Healthy newborns with oral thrush usually develop symptoms during the first few weeks of life. In addition to the distinctive white mouth lesions, infants may have trouble feeding or be fussy and irritable. They can also pass the infection to their mothers during breast-feeding. Women whose breasts are infected with Candida may experience the following signs and Symptoms:
- Unusually red or sensitive nipples
- Taut, shiny skin on the areola
- Unusual pain during nursing or painful nipples between feedings
- Stabbing pains deep within the breast
If you or your baby develops painful white lesions inside the mouth, see your doctor or dentist. Oral thrush can usually be diagnosed simply by looking at the lesions, but sometimes a small sample is examined under a microscope to confirm the diagnosis.
If thrush develops in older children or adolescents who have no other risk factors, seek medical care. An underlying condition such as diabetes may be the cause. In that case, your doctor will perform a thorough physical exam as well as recommend certain blood tests to help find the source of the problem.
Thrush that extends into the esophagus can be serious. To help diagnose this condition, your doctor may ask you to have one or more of the following tests :
- Throat culture. In this procedure, the back of your throat is swabbed with sterile cotton and the tissue sample cultured on a special medium to help determine which bacteria or fungi, if any, are causing your symptoms.
- Endoscopic examination. In this procedure, your doctor examines your esophagus, stomach and the upper part of your small intestine (duodenum) using a lighted, flexible tube with a camera on the tip (endoscope). The test, called an esophagogastroduodenoscopy, takes between 30 and 60 minutes. You'll be given a sedative to make you more comfortable and a local anesthetic so that you don't cough or gag when the endoscope is inserted. There's a slight risk of perforation of your esophagus, stomach or duodenum and of an adverse reaction to medication you may be given.
- Barium swallow. In this test, you'll need to drink one or two barium "milkshakes" — glasses of thick, chalky liquid that may be flavored so that they go down more easily. X-rays are then taken as the barium flows through your esophagus into your stomach.
Oral thrush is seldom a problem for healthy children and adults, although the infection may come back even after it's been treated. For people with compromised immune systems, however, thrush can be more serious.
Children with HIV may have especially severe symptoms in their mouth or esophagus, which can make eating painful and difficult. As a result, they don't receive adequate nutrition, just when they need it most. In addition, thrush is more likely to spread to other parts of the body in people with cancer, HIV or other conditions that weaken the immune system. In that case, the areas most likely to be affected include the digestive tract, lungs, liver and skin.
The goal of any treatment is to stop the rapid spread of the fungus, but the best approach may depend on your age and the cause of the infection.
Treating oral thrush in children
Toddlers with mild oral thrush who are otherwise healthy may need no treatment at all. If the infection develops after a course of antibiotics, your doctor may suggest adding unsweetened yogurt to your child's diet to help restore the natural balance of bacteria. Infants or older children with persistent thrush may need an antifungal medication.
Treating oral thrush in infants and nursing mothers
If you're breast-feeding an infant who has oral thrush, you and your baby will do best if you're both treated. Otherwise, you're likely to pass the infection back and forth. Your doctor may prescribe a mild antifungal medication for your baby and an antifungal cream for your breasts. If your baby uses a pacifier or feeds from a bottle, wash and rinse nipples and pacifiers every day until the thrush clears up.
Treating oral thrush in healthy adults
If you're a healthy adult with oral thrush, you may be able to control the infection by eating unsweetened yogurt or taking acidophilus capsules or liquid. Acidophilus is available in natural food stores and many drugstores. Some brands need to be refrigerated to maintain their potency. Yogurt and acidophilus don't destroy the fungus, but they can help restore the normal bacterial flora in your body. If this isn't effective, your doctor may prescribe an antifungal medication.
Treating oral thrush in adults with weakened immune systems
Most often, your doctor will recommend an antifungal medication, which may come in one of several forms, including lozenges, tablets or a liquid that you swish in your mouth and then swallow.
The normal course of treatment is usually 10 to 14 days. Unfortunately, Candida albicans can become resistant to antifungal medications, especially in people with late-stage HIV infection. A drug known as amphotericin B may be used when other medications aren't effective.
Some antifungal medications may cause liver damage. For this reason, your doctor will likely perform blood tests to monitor your liver function, especially if you require prolonged treatment or have a history of liver disease.
The following measures may help reduce your risk of developing Candida infections :
- Try using yogurt or acidophilus capsules when you take antibiotics.
- Treat any vaginal yeast infections that develop during pregnancy as soon as possible.
- If you smoke, ask your doctor about the best ways to quit.
- See your dentist regularly — at least every six to 12 months — especially if you have diabetes or wear dentures. Brush and floss your teeth as often as your dentist recommends.
- Try limiting the amount of sugar and yeast-containing foods you eat, including bread, beer and wine. These may encourage the growth of Candida.