The most current population-based series [from Sweden and Minnesota] have found that anoperineal involvement is seen in 14%
to 38% of patients with CrohnĂ˘Â€Â™s disease, with isolated perianal disease seen in only 5%. The prevalence of perianal manifestations
increases as the disease progresses distally, with only 15% of patients with ileocolic CrohnĂ˘Â€Â™s disease developing fistula but fistulae occurring
in 92% of patients with CrohnĂ˘Â€Â™s disease involving the colon and rectum. There does not appear to be a predilection for age, with
between 13% and 62% of children and adolescents with CrohnĂ˘Â€Â™s disease experiencing perianal manifestations; however, a younger age of
onset increases the odds of developing perianal disease over time. Perianal CrohnĂ˘Â€Â™s disease is often recurrent, with 35% to 59% of
patients relapsing within 2 years. More than 80% of patients require surgery, and as many as 31% require a permanent stoma.
The presence of perianal disease is associated with a more disabling natural history, with increased extraintestinal manifestations
and greater steroid resistance. Large studies have also shown an increased risk for squamous cell carcinoma and adenocarcinoma of the
anus in patients with anorectal involvement.
Last date updated on July, 2014