Acute Necrotizing Ulcerative Gingivitis (ANUG)

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

ByJames T. Ubertalli, DMD, Hingham, MA
Reviewed/Revised Apr 2024
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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 people who smoke and patients who are debilitated who are under stress. Other risk factors are poor oral hygiene, nutritional deficiencies, immunodeficiency (eg, HIV/AIDS, use of immunosuppressive medications), and sleep deprivation. Some patients also have oral candidiasis. The most common flora responsible for ANUG include Treponema, Selenomas, Bacteroides melaningenicus, and Fusobacterium spp (1).

General reference

  1. 1. Loesche WJ, Syed SA, Laughono SA, et al: The bacteriology of acute necrotizing ulcerative gingivitis. J Periodontol 53(4):223-230, 1982. https://doi.org/10.1902/jop.1982.53.4.223

Symptoms and Signs of ANUG

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 (closest to the teeth) 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.

Acute Necrotizing Ulcerative Gingivitis (ANUG)
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This rapidly progressing infection is characterized by acute fiery-red gingivitis, soft-tissue necrosis with formation of a necrotic surface layer (referred to as a pseudomembrane, best seen along the lower front gumline), and cratering of the interproximal papillae, referred to as "punched-out papillae."
Image courtesy of Craig Fowler, DDS.

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

Diagnosis of ANUG

  • 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.

Treatment of ANUG

  • Debridement

  • 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.

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

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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