Perineal Abscesses and Fistulae

Question 1

What is an anal fistulae.

Answer 1

An abnormal connection between a primary opening inside the anal canal and secondary opening in the perianal skin.

Question 2

What are the symptoms of perianal fistulae.

Answer 2

History of anorectal abscess.
Perianal discharge.
Persistent pain.

Question 3

What are the sings of perianal fistulae.

Answer 3

External opening on perineum.

There may be visible discharge.

Question 4

What is the cause of a perianal fistula. (5)

Answer 4

The majority form secondary to a perianal abscess. 
Other causes include:
Crohn's.
Carcinoma. 
TB.
Diverticular disease.

Question 5

What is Parks’ classification of anal fistulae.

Answer 5

It states the distribution of anal fistulae.
70% will be intersphincteric.
25% will be trans-sphincteric.
5% will be suprasphincteric.

Question 6

What is Goodall’s rule in relation to anal fistulae.

Answer 6

It asks you to imagine a transverse line through the anus in the lithotomy position.
Fistulae with an external opening anterior to this line will follow a straight line to the anus.
Fistulae with an opening posterior to this line follow a curved course to open in the midline (at the 6 o’clock position).

Question 7

What is an anorectal abscess.

Answer 7

An infection in the cryptoglandular epithelium lining the anal canal spreads to the surrounding soft tissues, with subsequent abscess formation.

Question 8

What are predisposing factors to develop anal abscesses. (5)

Answer 8

Crohn's disease.
Diabetes. 
Immunosupression.
TB.
Cancer.

Question 9

Where do anal abscesses form. (4)

Answer 9

Perianal - 45%. (between the internal and external sphincters).
Ischiorectal - 30%. (lateral to the sphincters).
Intersphincteric - 20%.
Supralevator - 5%.

Question 10

What are the symptoms of anal abscesses. (4)

Answer 10

Extreme anal or rectal pain. (usually worse on defecation).
Fever.
Rigors.
There can also be pus discharge.

Question 11

What are the sings of an anal abscess. (3)

Answer 11

Erythematous, indurated or fluctuant mass.

Question 12

What causes an anal abscess.

Answer 12

They usually result from infection of anal glands by normal intestinal bacteria.

Question 13

What is a complication of an anal abscess.

Answer 13

They may go on to develop anal fistulae.

Question 14

What causes an anal fistula.

Answer 14

Blockage of deep intramuscular gland ducts predisposes to the formation of abscesses, which discharge to form fistulae.