Differential diagnosis

Differential diagnosis

The only conditions with which an anorectal abscess is likely to be confused are abscesses connected with a pilonidal sinus, Bartholin’s gland or Cowper’s gland. Management of acute anorectal sepsis is primarily surgical, including careful examination under anaesthesia, sigmoid oscopy and proctoscopy , and adequate drainage of the pus. For perianal and ischiorectal sepsis (with an incidence of 60% and 30%, respectively), drainage is through the perineal skin. Traditionally this has been through a cruciate incision over the most fluctuant point, with excision of the skin edges to deroof the abscess; however, although drainage must be ensured, skin preservation is important and wide excision of otherwise healthy tissue should be avoided. A gentle search may be made for an underlying fistula if the surgeon is experienced; if obvi ous, a loose draining seton may be passed. Injudicious probing in the acute stage is, however, potentially dangerous and may lead to a much more di ffi cult situation. Unless by highly e enced hands, immediate fistulotomy should not be performed. Despite lack of evidence, the practice of packing the abscess cavity is commonplace. The management of supraleva tor sepsis is dependent upon its origin. Sepsis originating in pelvic disease necessitates appropriate management of the underlying cause (appen diceal, gynaecological, diverticular, Crohn’s disease , malig nancy), although intrarectal drainage may be appropriate to avoid creation of an extrasphincteric fistula. Summary box 80.11 Anorectal abscess /uni25CF /uni25CF /uni25CF /uni25CF

Presents as a painful, throbbing swelling in the anal region with associated pyrexia Classi /f_i ed according to anatomical site Treatment is drainage of pus and appropriate systemic antibiotics Consider underlying diagnosis: /f_i stula- in-ano , Crohn’s disease, diabetes, immunosuppression

Differential diagnosis

In the early stages, distinction from furunculosis can be di ffi cult. Crohn’s disease, cryptoglandular fistula, pilonidal sinus, tuberculosis, actinomycosis, lymphogranuloma venereum and granuloma inguinale must be considered when later stages present.