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Acute Necrotizing Ulcerative Gingivitis (ANUG)

(Trench Mouth; Vincent's Angina)


James T. Ubertalli

, DMD, Hingham, MA

Reviewed/Revised May 2022 | Modified Sep 2022
Topic Resources

Acute necrotizing ulcerative gingivitis (ANUG) is a painful infection of the gums that causes fever, 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.

Acute necrotizing ulcerative gingivitis 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 human immunodeficiency virus [HIV]/acquired immunodeficiency syndrome [AIDS] Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more Human Immunodeficiency Virus (HIV) Infection or immunosuppressive drugs). Acute necrotizing ulcerative gingivitis is not contagious.

Did You Know...

  • Acute necrotizing ulcerative gingivitis (ANUG) used to be called trench mouth, a term that comes from World War I, when many soldiers in the trenches developed the infection.

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 ANUG, as do physical or emotional stress, poor diet, and lack of sleep. The infection occurs most often in people who have gingivitis Gingivitis Gingivitis is a mild form of periodontal disease characterized by inflammation of the gums (gingivae). Gingivitis results most often from inadequate brushing and flossing but may result from... read more Gingivitis and then experience a stressful event (for example, final exam week or military basic training). Acute necrotizing ulcerative gingivitis is far more common among smokers than nonsmokers.

Symptoms of ANUG

Usually, ANUG 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.

Diagnosis of ANUG

  • A dentist's evaluation

When the breath smells extremely foul, dentists sometimes suspect the diagnosis of acute necrotizing ulcerative gingivitis (ANUG) immediately, as soon as they come into contact with affected people. Other times the diagnosis is evident from the appearance of the mouth and gums.

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

Treatment of ANUG

  • Professional cleaning

  • Mouth rinses

  • Sometimes antibiotics

  • Good oral hygiene

Treatment of acute necrotizing ulcerative gingivitis (ANUG) 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 (an antiseptic). 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). Dentists also recommend people rest, drink plenty of fluids, eat nutritious foods, and take drugs for pain. Dentists also recommend people avoid smoking or eating hot or spicy foods.

More Information

The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  • Mouth Healthy: This general resource provides information on oral health, including nutrition and guidance on selecting products that carry the American Dental Association's seal of approval. There is also advice on finding a dentist and how and when to see one.

  • National Institute of Dental and Craniofacial Research: This government site covers a wide variety of topics related to oral and dental health (in English and Spanish), including definitions of common terms and the latest information on clinical trials related to oral and dental diseases.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Betasept, Chlorostat, Hibiclens, Oro Clense , Peridex, Periogard, PerioRx , Perisol
Amoxil, Dispermox, Moxatag, Moxilin , Sumox, Trimox
A/T/S, Akne-mycin, E.E.S., Emcin Clear , EMGEL, E-Mycin, ERYC, Erycette, Eryderm , Erygel, Erymax, EryPed, Ery-Tab, Erythra Derm , Erythrocin, Erythrocin Lactobionate, Erythrocin Stearate, Ilosone, Ilotycin, My-E, PCE, PCE Dispertab , Romycin, Staticin, T-Stat
Emtet-500, Panmycin, Sumycin
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