Perirectal abscess management

Management of Perirectal Abscess:  Drain in the ED or OR?       

Perirectal abscesses almost always begin from obstruction of an anal crypt and its associated anal gland.  The normal anatomic pathway is for anal glands to drain out the anal crypt and into the anal canal.  However, when obstruction occurs, this drainage pattern is blocked, resulting in infection, inflammation, and abscess formation.

Abscesses are usually polymicrobial with both aerobic and anaerobic species. Infection can progress to involve any (or multiple) of the potential spaces in the area:  the perianal space (most common), the ischiorectal space (second most common), the intersphincteric space, the deep postanal space, and the supralevator space.  Patients can present with rectal and perianal pain, often worse with sitting and with defection, localized erythema and tenderness, fever, urinary retention, and signs of sepsis in severe infections.  Deeper abscesses may exhibit fewer localized signs, and tender inguinal adenopathy can be a clue to their presence.


It is crucial that emergency physicians distinguish between an isolated superficial perianal abscess and deeper abscesses.  Liberal use of CT scanning is recommended to aid in diagnosis.  

Isolated perianal abscess without any extension to deeper spaces is the only type of perirectal abscess which should be managed by an emergency physician.  These can be treated with incision and drainage, often with procedural sedation for patient comfort.  Because of involvement of deeper structures and potential for complications, all deeper abscesses should be managed by a general surgeon in the operating room.  

[From Tintinalli's Emergency Medicine:  A Comprehensive Study Guide, 7th Ed.  Tintinalli, JE, Ed, et al.  New York:  McGraw Hill, 2011:  594-596]