Health Update

by Dr. Gary S. Sy

ORAL thrush is a condition in which the fungus Candida albicans accumulates on the lining of your mouth.

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 in people with compromised immune systems. 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.

Causes

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. This group of rare disorders is marked by a chronic candida infection of your mouth and fingernails and of the skin on your scalp, trunk, hands and feet. Scaly, crusted lumps known as granulomas also may develop in your mouth or on your nails and skin.

* 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 the most common opportunistic infections is oral thrush. Thrush is rare in the early stage of AIDS. It usually only appears if levels of the virus-fighting cells known as CD4 fall below 300.

* 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 your 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. Many women experience at least one vaginal yeast infection (Candida vulvovaginitis) before menopause. Vaginal yeast infections are caused by the same fungus that causes oral thrush. Although a yeast infection isn’t dangerous, if you’re pregnant you can pass the fungus to your baby during delivery. As a result, your newborn may develop oral thrush within the first several weeks after birth.

Risk factors

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 oral corticosteroids or antibiotics

* Use a corticosteroid inhaler for asthma

When to seek medical advice

If you or your baby develops painful white lesions inside the mouth, see your doctor or dentist.

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.

Screening and diagnosis

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.

In older children or adolescents who have no other risk factors, an underlying medical condition may be the cause of oral thrush. If your doctor suspects that to be the 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 they go down more easily. X-rays are then taken as the barium flows through your esophagus into your stomach.

Source: Manila Bulletin