Perianal abscess

A perianal abscess (also called anorectal abscess) is a collection of pus outside the anus. It arises from an infection at one of the anal crypts of Morgani which leads to inflamation and abscess formation. Most cases of perianal abscesses are sporadic, though there are certain situations which elevate the risk for developing the disease, such as diabetes mellitus, crohn's disease, chronic steroid treatment and others. Ischiorectal, inter and intrasphincteric abscesses have been described.

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Pain in the perianal area is the most common symptom of an anorectal abscess. The pain may be dull, aching, or throbbing. It is worse when the person sits down and right before a bowel movement. After the individual has a bowel movement, the pain usually lessens. Other signs and symptoms of anorectal abscess include constipation, drainage from the rectum, fever and chills, or a palpable mass near the anus.

Diagnosis of anorectal abscess begins with a medical history and physical exam. Imaging studies which can help determine the diagnosis in cases of a deep non-palpable perirectal abscess include pelvic CT scan, MRI or trans-rectal ultrasound. These studies are not necessary, though, in cases which the diagnosis can be made upon physical exam.

Treatment of perianal abscesses include examination under anesthesia (regional or general), incision and drainage of the pus. Antibiotics to cover rectal flora (and not skin flora) should be prescribed perioperatively. An anorectal abscess that is untreated or not fully drained can get worse and cause a severe local or systemic infection which can be life-threatening (Fornier's gangrane or sepsis). On the long run, a perianal fistula can arise from the abscess cavity - an abnormal tract that connects the rectum and the external perianal region.

After successful treatment and recovery, a person can generally return to normal activities. However, someone with inflammatory bowel disease often needs lifelong monitoring by a healthcare provider. Any new or worsening symptoms should be reported to the healthcare provider.