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.
90% are caused by blocked anal glands with no obvious underlying cause
- thought that tight anal sphincter may contribute to the blockage
they account for ~60% of anorectal abscesses with other sites being:
- ischiorectal 20%, intersphincteric 5%, supralevator 4%, and submucosal 1%
most common in 3rd and 4th decades of life but is also quite common in infants
affects males 2-3x more than females
30% have a PH of a perianal abscess
appears to be more common in Spring and Summer
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
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
consider antibiotics if extensive cellulitis