title: Perianal disease in patients with ulcerative colitis: A case-control study.
abstract: BACKGROUND
  Patients with ulcerative colitis (UC) and concomitant perianal disease (PAD) are occasionally seen, but the impact of PAD on UC outcome has been scarcely assessed.
  
  
  OBJECTIVE
  To evaluate the prevalence, clinical features and outcomes of PAD among UC patients.
  
  
  METHODS
  Patients with an initial diagnosis of UC who ever developed PAD were identified from three IBD hospital databases. Each case was matched by age, disease extent at diagnosis, and year of diagnosis, with two UC patients who never developed PAD.
  
  
  RESULTS
  Thirty-seven UC patients (5% of the whole series) developed PAD (complex in about a half of them), being more frequent among men (62%), with distal (50%) or extense (34%) disease. Proximal spread of UC occurred in 19% of cases. No differences in demographic features, rate of proximal spread or colectomy during follow-up were found as compared to controls, but greater requirements of steroids (P=0.019) were detected in UC-PAD patients. A change in disease diagnosis occurred in 6 patients mainly because of transmural involvement in colectomy specimen, small intestinal involvement, and/or endoscopic appearance.
  
  
  CONCLUSIONS
  PAD may occur in up to 5% of UC patients. When complex it leads to a change in disease diagnosis in one third of cases. UC-related therapeutic requirements are not increased in these patients, except for steroids.
authors.affiliation: Hospital Universitari Germans Trias i Pujol, Badalona, Catalonia, Spain.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Zabana
authors.forename: Manuel
authors.initials: M
authors.lastname: Van Domselaar
authors.forename: Esther
authors.initials: E
authors.lastname: Garcia-Planella
authors.forename: Míriam
authors.initials: M
authors.lastname: Mañosa
authors.forename: Antonio López
authors.initials: AL
authors.lastname: San Román
authors.forename: Jordi
authors.initials: J
authors.lastname: Gordillo
authors.forename: Eduard
authors.initials: E
authors.lastname: Cabré
authors.forename: Eugeni
authors.initials: E
authors.lastname: Domènech
mesh_terms: D000328:Adult; D001004:Anus Diseases / Q000453:epidemiology*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors