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Acute Necrotizing Ulcerative Gingivitis (ANUG)

(Fusospirochetosis; Trench Mouth; Vincent Infection or Vincent Angina)


James T. Ubertalli

, DMD, Hingham, MA

Last full review/revision Jul 2020| Content last modified Jul 2020
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Topic Resources

Acute necrotizing ulcerative gingivitis is a painful infection of the gums. Symptoms are acute pain, bleeding, and foul breath. Diagnosis is based on clinical findings. Treatment is gentle debridement, improved oral hygiene, mouth rinses, supportive care, and, if debridement must be delayed, antibiotics.

Acute necrotizing ulcerative gingivitis (ANUG) occurs most frequently in smokers and debilitated patients who are under stress. Other risk factors are poor oral hygiene, nutritional deficiencies, immunodeficiency (eg, HIV/AIDS, use of immunosuppressive drugs), and sleep deprivation. Some patients also have oral candidiasis.

Symptoms and Signs

The usually abrupt onset may be accompanied by malaise or fever. The chief manifestations are

  • Acutely painful, bleeding gingivae

  • Excessive salivation

  • Sometimes overwhelmingly foul breath (fetor oris)

Ulcerations, which are pathognomonic, are present on the dental papillae and marginal gingiva. These ulcerations have a characteristically punched-out appearance and are covered by a gray pseudomembrane. Similar lesions on the buccal mucosa and tonsils are rare. Swallowing and talking may be painful. Regional lymphadenopathy often is present.

Often, ANUG can manifest without a significant odor, and it also may manifest as a localized condition.


  • Clinical evaluation

Rarely, tonsillar or pharyngeal tissues are affected, and diphtheria or infection due to agranulocytosis must be ruled out by throat culture and complete blood count when the gum manifestations do not respond quickly to conventional therapy.


  • Debridement

  • Rinses (eg, hydrogen peroxide, chlorhexidine)

  • Improved oral hygiene

  • Sometimes oral antibiotics

Treatment of ANUG consists of gentle debridement with a hand scaler or ultrasonic device. Debridement is done over several days. The patient uses a soft toothbrush or washcloth to wipe the teeth.

Rinses at hourly intervals with warm normal saline or twice a day with 1.5% hydrogen peroxide or 0.12% chlorhexidine may help during the first few days after initial debridement.

Essential supportive measures include improving oral hygiene (done gently at first), adequate nutrition, high fluid intake, rest, analgesics as needed, and avoiding irritation (eg, caused by smoking or hot or spicy foods). Marked improvement usually occurs within 24 to 48 hours, after which debridement can be completed.

If debridement is delayed (eg, if a dentist or the instruments necessary for debridement are unavailable), oral antibiotics (eg, amoxicillin 500 mg every 8 hours, erythromycin 250 mg every 6 hours, or tetracycline 250 mg every 6 hours) may help to provide relief and can be continued until 72 hours after symptoms resolve.

Treatment of oral candidiasis is described elsewhere.

If the gingival contour inverts (ie, if the tips of papillae are lost) during the acute phase, surgery is eventually required to prevent subsequent periodontitis.

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NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version

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