Perianal abscess - perianal abscess

This is a condition in which an abscess forms around the anus and rectum as a result of perianal inflammation. The source of infection is often the anal glands, but infection can also occur through anal fissures or rectal foreign body wounds. Although rare, perianal abscesses can also occur with ulcerative colitis and Crohn's disease. The most common sites for abscess formation are the low intersphincter space, the ischiorectal fossa, subcutaneous anal space, high intersphincter space, pelvic rectal fossa, and submucosal space of the rectum. Perianal abscesses that have spread deep present with dull pain in the anus, fever, and leukocytosis. Subcutaneous abscesses are more painful. The most common causative bacteria is Escherichia coli, with staphylococci and streptococci also seen. In very rare cases, mixed infection with gas-producing anaerobic bacteria can also be seen. Recently, tuberculosis bacteria have become rare. Abscesses should be incised as soon as possible, and simple abscesses can be cured simply by draining the pus. Large abscesses or those that are deep in the anus should first be incised and drained to stop the spread of pus, and then a radical operation to repair the anal fistula should be performed. Antibiotics are generally ineffective for perianal abscesses.

[Hiroshi Takema]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

肛門周囲炎の結果、肛門直腸周囲に膿瘍を形成した状態をいう。感染源は肛門腺(せん)にあることが多いが、裂肛や直腸異物創(そう)からの感染もあり、まれではあるが潰瘍(かいよう)性大腸炎、クローン病などで肛門周囲膿瘍になることがある。膿瘍のできる部位は、頻度の高いものからあげると、低位内外括約筋間、坐骨(ざこつ)直腸窩(か)、肛門皮下、高位内外括約筋間、骨盤直腸窩、直腸粘膜下の順である。深部に及んだ肛門周囲膿瘍では、肛門部の鈍痛と発熱、白血球増多を示す。疼痛(とうつう)は皮下に及んだもののほうがかえって強い。起炎菌中もっとも多いのは大腸菌で、ブドウ球菌や連鎖球菌もみられる。ごくまれにガス産生嫌気性菌の混合感染をみることもある。最近、結核菌はまれである。膿瘍は一刻も早く切開すべきであり、簡単なものは排膿だけで治る。大きな膿瘍や深部に及ぶものは、まず切開、排膿して膿の広がりを止め、二次的に痔瘻(じろう)根治手術を行う。肛門周囲膿瘍では抗生物質はまず無効である。

［竹馬　浩］

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