Anorectal sepsis

Question 1

Define perianal abscess?

Answer 1

• Nonspecific term encompassing abscess in the following spaces:
  
  • Perianal
  • Intersphincteric
  • Ischiorectal
  • Pelvirectal
• More commen in men

Question 2

Describe the pathogenesis of an ano-rectal abscess?

Answer 2

• Most abscesses are cryptoglandular
• Initiated by blockage of anal gland ducts
• Secondary infection with colonic organisms

Question 3

Name some factors which predispose to perianal abscesses?

Answer 3

• Crohns
• Ulcerative colitis
• Immunosuppressive disorders:
  
  • DM
  • HIV
  • Chemotherapy
  • Haematological

Question 4

Name some associations of peri-anal sepsis?

Answer 4

• DM
• Crohns
• Malignancy

Question 5

Describe the presentation of peri-anal sepsis?

Answer 5

• Throbbing peri-anal pain
  
  • Worse on sitting
• Occasionally a purulent anal discharge

Question 6

Describe some examination findings of peri-anal sepsis?

Answer 6

• Perianal mass or cellulitic area
• Fluctuant mass on PR
• Septic signs: fever, tachycardia

Question 7

Describe the treatment for abscesses?

Answer 7

• Antibioitics + surgical drainage
• May require examination under anaesthetic
  
  • Wound packed
• Majority of abscesses don’t require antibiotics after drainage
  
  • If extensive cellulitis, cephalosporins + metronidazole

Question 8

Describe the clinical features of a True perianal abscess?

Answer 8

• Most common
• Pus tracks inferiorly to appear at the perianal margin between sphincters
• Abscess may discharge spotaneously
• Pain is main complaint

Question 9

Describe the clinical features of a Intersphincteric abscess?

Answer 9

• Abscess remains localised within the intersphicnter space
• Acute anal pain and tenderness
  
  • Prevents digital examination (GA often required)
• Diagnosed by demonstration of pea-sized lump in the intersphincteric space

Question 10

Main differential for a Intersphincteric abscess?

Answer 10

Acute anal fissure

Question 11

Describe Ischiorectal abscesses?

Answer 11

• Infection extends into ischiorectal space
• Poorly controlled diabetes often underlying
• Infection can track around the anus to the contralateral space
• Fluctuant swelling of both buttocks, perianal pain, difficulty sitting

Question 12

Describe Supralevator abscesses?

Answer 12

• Infection tracks to the upper intersphincteric space causing:
  
  • High intersphincter abscess
  • Pelvirectal abscess
• Abscesses can be bilateral
• Systemic upset

Question 13

Complication of abscess drainage?

Answer 13

Formation of a fistula