title: Frequency and risk factors for extraintestinal manifestations in the Swiss inflammatory bowel disease cohort.
abstract: OBJECTIVE
  Data on the frequency of extraintestinal manifestations (EIMs) in Crohn's disease (CD) and ulcerative colitis (UC) and analyses of their risk factors are scarce. We evaluated their prevalence and risk factors in a large nationwide cohort of inflammatory bowel disease (IBD) patients.
  
  
  METHODS
  IBD patients from an adult clinical cohort in Switzerland (Swiss IBD cohort study) were prospectively included. Data from validated physician enrolment questionnaires were analyzed.
  
  
  RESULTS
  A total of 950 patients were included, 580 (61%) with CD (mean age 41 years) and 370 (39%) with UC (mean age 42 years). Of these, 249 (43%) of CD and 113 (31%) of UC patients had one to five EIMs. The following EIMs were found: arthritis (CD 33%, UC 21%), aphthous stomatitis (CD 10%, UC 4%), uveitis (CD 6%, UC 4%), erythema nodosum (CD 6%, UC 3%), ankylosing spondylitis (CD 6%, UC 2%), psoriasis (CD 2%, UC 1%), pyoderma gangrenosum (CD and UC each 2%), and primary sclerosing cholangitis (CD 1%, UC 4%). Multiple logistic regression identified the following risk factors for ongoing EIM in CD: active disease (odds ratio (OR)=1.95, 95% confidence interval (CI)=1.17-3.23, P=0.01), and positive IBD family history (OR=1.77, 95% CI=1.07-2.92, P=0.025). No risk factors were identified in UC patients.
  
  
  CONCLUSIONS
  EIMs are a frequent problem in CD and UC patients. Active disease and positive IBD family history are associated with ongoing EIM in CD patients. Identification of EIM prevalence and associated risk factors may result in increased awareness for this problem and thereby facilitating their diagnosis and therapeutic management.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University Hospital, Zurich, Switzerland. stephan.vavricka@usz.ch
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Vavricka
authors.forename: Lionel
authors.initials: L
authors.lastname: Brun
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Ballabeni
authors.forename: Valérie
authors.initials: V
authors.lastname: Pittet
authors.forename: Bettina Mareike
authors.initials: BM
authors.lastname: Prinz Vavricka
authors.forename: Jonas
authors.initials: J
authors.lastname: Zeitz
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rogler
authors.forename: Alain M
authors.initials: AM
authors.lastname: Schoepfer
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D001168:Arthritis / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000453:epidemiology*; D016001:Confidence Intervals; D003424:Crohn Disease / Q000175:diagnosis* / Q000453:epidemiology*; D004893:Erythema Nodosum / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000453:epidemiology; D008107:Liver Diseases / Q000175:diagnosis / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D011446:Prospective Studies; D011565:Psoriasis / Q000175:diagnosis / Q000453:epidemiology; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000453:epidemiology; D013557:Switzerland / Q000453:epidemiology; D014605:Uveitis / Q000175:diagnosis / Q000453:epidemiology