Acute Necrotizing Ulcerative Gingivitis

(ANUG; Trench Mouth; Vincents Stomatitis)


Acute necrotizing ulcerative gingivitis (ANUG) is a serious infection of the gums.


The exact cause is not known. It happens when there is excess bacteria in the mouth.

Risk Factors

This problem is more common in people who are 24 years of age and younger. The risk is higher in people who have excess bacteria in the mouth due to:

  • Lack of dental care
  • Poor dental hygiene
  • Poor diet
  • Vitamin deficiencies
  • Infections in the throat, teeth, or mouth
  • A weak immune system
  • Smoking
  • Stress


Problems may be:

  • Fever
  • Red and swollen gums
  • Gums that bleed easily
  • Gum pain
  • Bad taste in the mouth
  • Very bad breath
  • Gray buildup on the gums
  • Large sores or loss of gum in between teeth

Red and Swollen Gums

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The doctor will ask about your symptoms and health history. A dental exam will be done.

Images may be taken of your teeth and face. This can be done with x-rays.

Dental X-ray

Jaw x-ray teeth
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Any underlying causes will need to be treated, such as improving nutrition and dental care.

The goals of treatment are to ease pain and stop the disease from getting worse. Options are:

  • Dental surgery to remove damaged tissue
  • Antibacterial mouthwash
  • Medicine to:
    • Ease pain
    • Treat infection


The risk of this health problem may be lowered by:

  • Practicing good oral hygiene
  • Eating a healthful diet
  • Managing stress


American Academy of Periodontology
Mouth Healthy—American Dental Association


Canadian Dental Association


Acute necrotizing ulcerative gingivitis. EBSCO DynaMed website. Available at: Accessed August 16, 2021.
Acute necrotizing ulcerative gingivitis. Merck Manual Professional Version website. Available at: Accessed August 16, 2021.
Last reviewed July 2021 by EBSCO Medical Review Board James Cornell, MD