Definition

Thrush is an infection of the mouth. It usually begins on the tongue and inside of the cheeks, and spread to the roof of the mouth, gums, tonsils, and throat.

Causes

Thrush is caused by a fungus. The immune system can normally fight off this fungus but the fungus can grow and spread if the immune system is weakened.

Risk Factors

Certain situations can weaken the immune system either in the body or locally in the mouth. A weakened immune system increases your risk for thrush. Factors that can weaken your immune system include:

• Health conditions such as:
  • HIV infection
  • Diabetes
  • Leukemia

• Certain medications such as:
  • Corticosteroid inhalers
  • Medications that treat psychiatric conditions
  • Antibiotics

• Imbalance of healthy microorganisms in the mouth which can be caused by:
  • Wearing dentures
  • Prolonged illness
  • Conditions that cause a dry mouth

Symptoms

In some cases, you may not have symptoms. In those that have symptoms, thrush may cause:

• White or red patches on the inside of the cheeks or tongue that may or may not come off when rubbed
• Sore mouth or throat
• Difficulty swallowing
• Differences in taste
• Fissures or cracks in the mouth

Thrush can spread beyond the mouth. Complications include infections that spread to the:

• Esophagus—the tube that carries food from the mouth to the stomach
• Urinary tract
• Whole body— sepsis causes multiple organ failure and death

Diagnosis

Your doctor will ask you about your symptoms and medical history. A physical exam will be done, including an inspection of your mouth. Diagnosis can usually be made based on your symptoms. Your doctor may take a sample of cells from the affected area to examine under a microscope.

Treatment

The goal of treatment is to restore the normal balance of bacteria and yeast in the mouth. If any underlying conditions contribute to thrush, they will also be treated.

Treatments include:

Prevention

To help reduce your chance of thrush:

• Maintain proper oral hygiene.
• If you have a condition that affects your immune system, ask your doctor about taking antifungal medication as a preventive measure.
• Limit your use of mouthwashes and mouth sprays. These can upset the normal balance of yeast and bacteria in your mouth.
• If you use a corticosteroid inhaler, rinse your mouth thoroughly after each use.

National Foundation for Infectious Disease http://www.nfid.org

Public Health Agency of Canada http://www.phac-aspc.gc.ca

Dentures. American Dental Association Mouth Healthy website. Available at:
http://www.mouthhealthy.org/en/az-topics/d/Dentures
Accessed December 9, 2013.

Greenspan D, Greenspan JS. HIV-related oral disease. Lancet. 1996;348(90290:729-733.

Oropharyngeal/esophageal candidiasis (Thrush). Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/fungal/diseases/candidiasis/thrush/index.html
Updated May 6, 2013. Accessed December 9, 2013.

Oral candidiasis in children and adults. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated October 1, 2013. Accessed December 9, 2013.

A prospective, randomized, double-blind, placebo-controlled trial evaluating the effects of nystatin on the development of oral irritation in patients receiving high-dose intravenous interleukin-2. J Immunother. 2001;24(2):188-192.