Thrush

Alternative names

Candidiasis - oral; Oral thrush

Definition

Oral thrush is a yeast infection of the mucous membranes of the mouth and tongue.

Causes, incidence, and risk factors

Thrush is caused by a fungus called Candida albicans. This organism lives in your mouth and is usually kept in check by healthy organisms that also live there. However, when your resistance to infection is low, the fungus can grow, leading to lesions in your mouth and on your tongue.

The following can lessen your resistance to infection and increase your chances of getting thrush:

• Taking antibiotics or steroid medications
  
• Having HIV or AIDS
  
• Receiving chemotherapy for cancer or drugs to suppress your immune system following an organ transplant
  
• Being very old or very young
  
• Being in poor health
  
• Having diabetes
  

Thrush is commonly seen in infants. It is not considered abnormal in infants unless it lasts longer than a couple weeks.

Candida albicans can also cause yeast infections in the vagina.

Symptoms

Thrush appears as whitish, velvety plaques in the mouth and on the tongue. Underneath the whitish material, there is red tissue that may bleed. The lesions can slowly increase in number and size.

If you are immunocompromised (for example, you are HIV positive or receiving chemotherapy), the infection can spread to other organs, like the esophagus (causing pain with swallowing), or throughout your body, which can be fatal.

Signs and tests

Your doctor or dentist can almost always diagnose thrush by looking at your mouth and tongue. These fungal lesions have a distinct appearance. If not entirely clear, one of the following tests may be performed to look for the candida organisms:

• Microscopic examination of mouth scrapings
  
• Culture of mouth lesions
  

Treatment

For thrush in infants, treatment is often NOT necessary. It generally resolves on its own within two weeks.

There are two goals when treating oral thrush in adults. The first is to improve your immune system's ability to function. For example, in diabetics, good control of the diabetes may be enough to clear the infection without other treatment.