Trench Mouth – for patients (Humans)

(Acute Necrotizing Ulcerative Gingivitis; ANUG; Vincent Infection; Vincent Angina)

By James T. Ubertalli, DMD, Private Practice, Hingham, MA

 (See also Introduction to Periodontal Diseases.)

Trench mouth is a painful infection of the gums, causing pain, fever, and sometimes foul-smelling breath and feeling ill.

  • If the normal bacteria in the mouth overgrow, the gums can become infected.
  • The gums hurt, and people sometimes have extremely bad breath.
  • A professional cleaning, sometimes followed by hydrogen peroxide rinses and antibiotics, plus good oral hygiene are effective.

The term trench mouth comes from World War I, when many soldiers in the trenches developed the infection. The medical term is acute necrotizing ulcerative gingivitis (ANUG). Trench mouth is now rare, but minor gum infections involving just a few teeth probably occur relatively commonly. The severe form usually affects only people with an impaired immune system (for example, due to HIV/AIDS or immunosuppressive drugs). Trench mouth is not contagious.

The infection is caused by an abnormal overgrowth of the bacteria that normally exist harmlessly in the mouth. Poor oral hygiene usually contributes to the development of trench mouth, as do physical or emotional stress, poor diet, and lack of sleep. The infection occurs most often in people who have gingivitis and then experience a stressful event (for example, final exam week or military basic training). Trench mouth is far more common among smokers than nonsmokers.


Usually, trench mouth begins abruptly with painful and bleeding gums, excessive saliva production, and sometimes extremely foul-smelling breath. People may also have a fever and feel ill. The tips of the gums between the teeth appear punched-out and become sores (ulcers) covered with a gray layer of dead tissue. The gums bleed easily, and talking, eating, and swallowing cause pain. Often, the lymph nodes under the jaw swell, and a mild fever develops.


  • A doctor’s evaluation

When the breath smells so foul, doctors sometimes suspect the diagnosis of trench mouth immediately, as soon as they come into contact with affected people. Other times the diagnosis is evident to the doctor from the appearance of the mouth and gums.

If the gums do not respond quickly to therapy, doctors may do other tests to rule out other causes.


  • Professional cleaning
  • Mouth rinses
  • Sometimes antibiotics
  • Good oral hygiene

Treatment of trench mouth begins with a gentle, thorough, professional cleaning done over several days.

At home, people are instructed to rinse with salt water, a hydrogen peroxide solution (ordinary drugstore hydrogen peroxide mixed half-and-half with water), or chlorhexidine. Rinsing may be recommended instead of brushing for the first few days because of the sensitivity of the gums. People can use a soft toothbrush or washcloth to wipe the teeth.

If the cleaning must be delayed (for example, if a dentist or the proper tools are not available), doctors give antibiotics by mouth (such as amoxicillin, erythromycin, or tetracycline).

The infection responds very well to good oral hygiene (daily brushing and flossing). Doctors also recommend people rest, drink plenty of fluids, eat nutritious foods, and take drugs for pain. Doctors also recommend people avoid smoking or eating hot or spicy foods.


Merck Manual