Oral thrush

DEFINITION

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, the elderly, and in people with suppressed immune systems or certain health conditions, or those who take certain medications. Oral thrush is a minor problem if you’re healthy, but if you have a weakened immune system, symptoms of oral thrush may be more severe and difficult to control.

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 fungi and allowing an oral thrush infection to take hold.

Oral thrush and other candida infections can occur when your immune system is weakened by disease or by drugs such as prednisone, or when antibiotics disturb the natural balance of microorganisms in your body.

These diseases and conditions may make you more susceptible to oral thrush infection:

• HIV/AIDS. Human immunodeficiency virus (HIV) — the virus that causes AIDS — damages or destroys cells of your immune system, making you more susceptible to opportunistic infections that your body would normally resist. Repeated bouts of oral thrush, along with other symptoms, may be early indications of an immune deficiency, such as HIV infection.
• Cancer. If you have cancer, your immune system is likely to be weakened from the disease and from treatments such as chemotherapy and radiation. Both the disease and treatments can increase your risk of candida infections such as oral thrush.
• Diabetes mellitus. 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. 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.

SYMPTOMS

Initially, you may not even notice symptoms of oral thrush. Depending on the underlying cause, signs and symptoms may develop slowly or suddenly, and they may persist for days, weeks or months. 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 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 (especially in denture wearers)
• A cottony feeling in your mouth
• Loss of taste

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 (Candida esophagitis). If this occurs, you may experience difficulty swallowing 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 painful white lesions inside the mouth, see your doctor or dentist. If thrush develops in older children or teenagers, seek medical care. An underlying medical condition or certain treatments may be the cause.