perianal abscess

Introduction

perianal abscesses are abscesses in the soft tissue surrounding the anal canal arising from the anal crypts, initially forming in the intersphincteric space, and are often associated with a fistula tract (fistula-in-ano), particular if the patient has Crohn's disease.
they account for ~60% of anorectal abscesses with other sites being:
- ischiorectal 20%, intersphincteric 5%, supralevator 4%, and submucosal 1%

90% are caused by blocked anal glands with no obvious underlying cause
- thought that tight anal sphincter may contribute to the blockage
common organisms implicated in abscess formation include E. coli, Enterococci species, and Bacteroides species

current presentation including
- fever, discharge, local cellulitis, tenderness, painful defeacation, recent bowel history
past history:
- inflammatory bowel disease (IBD)
- previous perianal abscess
- obstetric history
- trauma
- diverticular disease

confirm diagnosis by examination finding of tender, peri-anal indurated swelling
- exclude Fournier's gangrene which can be the primary condition or a complication of a peri-anal abscess
nil orally
iv maintenance fluids
analgesia - usually opiates
blood glucose level if diabetic
contact surgical registrar for admission and definitive Mx in theatre
4/24 obs
fluid balance chart
DVT prophylaxis if not mobile or at risk
consider antibiotics if extensive cellulitis