This article is about the physiologic disorder. For the similarly named band, see Trenchmouth
Acute necrotizing ulcerative gingivitis (ANUG) or necrotizing ulcerative gingivitis (NUG) is a sub-classification of necrotizing periodontal disease, an infection of the gum tissue. This presents as an acute infection of the gingiva without involvement of the other tissues of the periodontium. If the infection has progressed deeper into the periodontal tissues, it is subclassified as "necrotizing ulcerative periodontitis" (NUP).
The condition is also commonly referred to as "trench mouth" and "Vincent's angina", named after French physician Jean Hyacinthe Vincent (1862–1950). Other synonyms include "acute membranous gingivitis", "fusospirillary gingivitis", " fusospirillosis", "fusospirochetal gingivitis", "necrotizing gingivitis", "phagedenic gingivitis", "ulcerative gingivitis", "Vincent stomatitis", "Vincent gingivitis", and "Vincent infection".
Necrotizing periodontal disease is caused by a 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.
Signs and symptoms 
Clinical features of necrotizing periodontal disease may include:
Coincident factors may include heavy smoking and poor nutrition, especially for those presenting with necrotizing ulcerative periodontitis.
Treatment includes irrigation and debridement of necrotic areas (areas of dead and/or dying gum tissue), oral hygiene instruction and the uses of mouth rinses and pain medication. As these diseases are often associated with systemic medical issues, proper management of the systemic disorders is appropriate.
Untreated, the infection may lead to rapid destruction of the periodontium and can spread, as necrotizing stomatitis or noma, into neighbouring tissues in the cheeks, lips or the bones of the jaw. As stated, 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.
See also