Acute necrotizing ulcerative gingivitis


Trench mouth
Acute membranous gingivitis
Fusospirillary gingivitis
Phagedenic gingivitis
Vincent's stomatitis
Vincent's infection
Vincent's gingivitis


Acute necrotizing ulcerative gingivitis is a common, non-contagious infection of the gums with sudden onset. The main features are painful, bleeding gums, and ulceration of inter-dental papillae (the sections of gum between adjacent teeth). This disease, along with necrotizing (ulcerative) periodontitis (NP or NUP) is classified as a necrotizing periodontal disease, one of the seven general types of periodontitis. The often severe gingival pain that characterizes ANUG distinguishes it from the more common chronic periodontitis which is rarely painful. ANUG is the acute presentation of necrotizing ulcerative gingivitis (NUG), which is the usual course the disease takes. If improperly treated or neglected, NUG may become chronic and/or recurrent. The causative organisms are mostly anaerobic bacteria, particularly Fusobacteria and Spirocaete species. Predisposing factors include poor oral hygiene, smoking, malnutrition, psychological stress and immunosuppression (sub-optimal functioning of the immune system). When the attachments of the teeth to the bone are involved, the term NUP is used. Treatment of ANUG is by debridement (although pain may prevent this) and antibiotics (usually metronidazole) in the acute phase, and improving oral hygiene to prevent recurrence. Although the condition has a rapid onset and is debilitating, it usually resolves quickly and does no serious harm. The synonym "trench mouth" arose during World War I as many soldiers developed the disease, probably because of the poor conditions and extreme psychological stress.


In the early stages some patients may complain of a feeling of tightness around the teeth. Three signs/symptoms must be present to diagnose this condition:

  • Severe gingival pain
  • Profuse gingival bleeding that requires little or no provocation.
  • Interdental papillae are ulcerated with necrotic slough. The papillary necrosis of NUG has been described as "punched out".

Other signs and symptoms may be present, but not always.

  • Oral malodor (intraoral halitosis)
  • Bad taste (metallic taste)

Malaise, fever and or cervical lymph node enlargement are rare (unlike the typical features of herpetic stomatitis). Pain is fairly well localized to the affected areas. Systemic reactions may be more pronounced in children. Cancrum oris (noma) is a very rare complication, usually in debilitated children. Similar features but with more intense pain may be seen in necrotizing periodontitis in HIV/AIDS.


Necrotizing periodontal disease is caused by a mixed bacterial infection that includes anaerobes such as P. intermedia and Fusobacterium as well as spirochetes, such as Treponema.

ANUG may also be associated with diseases in which the immune system is compromised, including HIV/AIDS. ANUG is an opportunistic infection that occurs on a background of impaired local or systemic host defenses. The predisposing factors for ANUG are smoking, psychological stress, malnutrition and immunosuppression.

Zones of infection have been described. These are (superficial to deep) the bacterial zone, the neutrophil rich zone, the necrotic zone and the spirochetal zone.


Diagnosis is usually clinical. Smear for fusospirochaetal bacteria and leukocytes; blood picture occasionally. The important differentiation is with acute leukaemia or herpetic stomatitis.


Untreated, the infection may lead to rapid destruction of the periodontium and can spread, as necrotizing stomatitis, into neighbouring tissues in the cheeks, lips or the bones of the jaw. The condition can occur and be especially dangerous in people with weakened immune systems. This progression to noma is possible in malnourished susceptible individuals, with severe disfigurement possible.


Treatment is by the simple reduction of the bacteria through improved oral cleaning and salt water or hydrogen peroxide-based rinses. Chlorhexidine or metronidazole can also be used in addition. Penicillin is also indicated at 250 mg every 6 to 8 hours. 


  • NIH