Perineal abscesses and fistulae Flashcards
Define Perineal Abscess?
a pus collection in the perineal region within the subcutaneous tissue of the anus.
define perineal fistula?
an abnormal chronically infected tract communicating between the perineal skin and either the anal canal or the rectum
what are the causes of perianal abscesses?
• Bacterial infection
o E.coli originating from GI
o Staph aureus originating from infection of skin
what are the causes of perianal fistulae?
• Fistulae develop as a complication of an abscess
• Fistulae can develop as a complications of Crohn’s disease
(pepper pit perineum)
risk factors of anal abscesses and fistulae?
o IBD
o Diabetes mellitus (bad wound healing)
o Malignancy (due to risk of bowel perforation)
epidemiology of anal abscesses and fistulae?
- COMMON
- More common in men
- Average age is 40
what is the presenting complaint of abscesses and fistulae?
- Constant throbbing pain in the perineum worse on sitting
- Pus-like discharge from the anal region
- Hardened tissue in the anal region
- Personal or family history of IBD
- Can present with spiking temperatures (for abscesses- SBA clue)
- Patients may be unable to defecate due to pain
what are the signs of abscesses and fistulae on DRE?
o A thickened area over the abscess/fistula may be felt
o DREs are not always possible due to pain and anal sphincter spasm
what is goodsalls law?
o This is a rule that allows you to correlate the location of the internal fistula opening based on the location of the external fistula opening
- openings anterior to anal canal run directly into anal canal
- openings posterior to anal canals follow a curved path.
what investigations should be undertaken for perianal abscesses and fistulae?
• Bloods o FBC o CRP o ESR o Blood culture • Imaging o MRI – gold standard (rarely used) o Trans-perineal USS
management plan for perianal abscesses?
- Requires SURGICAL treatment
* Incision and drainage of Abscess
management for perianal fistulae?
- low fistula = fistulotomy
- high fistula = seton.
when are antibiotics used for abscesses and fistulae?
- in cases of systemic infection
what are complications of perianal abscesses and fistulae?
- Recurrence
- Damage to internal anal sphincter
- Incontinence
- Persisting pain
prognosis for patients with perianal abscesses and fistulae?
• High recurrence rate without complete excision