title: Rosacea in Patients with Ulcerative Colitis and Crohn's Disease: A Population-based Case-control Study.
abstract: BACKGROUND
  Cutaneous manifestations are common in patients with inflammatory bowel diseases (IBDs) (ulcerative colitis [UC] and Crohn's disease [CD]). Previous case reports described patients with IBD who developed rosacea. IBD and rosacea are inflammatory epithelial diseases, presumably associated with changes in the innate immune system. We explored the association between IBD and incident rosacea.
  
  
  METHODS
  We conducted a population-based matched (1:1) case-control analysis on the association between IBD and rosacea, stratified by IBD disease duration and severity. We used data from the UK-based Clinical Practice Research Datalink. Cases had an incident diagnosis of rosacea recorded between 1995 and 2013.
  
  
  RESULTS
  Among 80,957 rosacea cases and the same number of controls, a history of UC was associated with an increased risk of rosacea (odds ratio [OR] 1.65, 95% confidence interval [CI], 1.43-1.90), with the highest OR in those with short UC duration (OR 2.85, 95% confidence interval, 1.80-4.50 for patients with <2 years of disease history). A history of CD yielded an overall OR of 1.49 (95% CI, 1.25-1.77), which did not correlate with disease duration. Additional analyses on IBD disease severity yielded evidence for a higher risk of rosacea in those with higher UC and CD activity.
  
  
  CONCLUSIONS
  Our findings provide evidence that patients with IBD may be at increased risk of rosacea (higher in UC), particularly during phases of increased IBD-associated gastrointestinal tract inflammation.
authors.affiliation: *Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland; †Hospital Pharmacy, University Hospital Basel, Basel, Switzerland; ‡Department of Gastroenterology and Nutrition, University Children Hospital Basel, Basel, Switzerland; and §Boston Collaborative Drug Surveillance Program, Boston University School of Public Health, Lexington, Massachusetts.
authors.forename: Julia
authors.initials: J
authors.lastname: Spoendlin
authors.forename: Gülistan
authors.initials: G
authors.lastname: Karatas
authors.forename: Raoul I
authors.initials: RI
authors.lastname: Furlano
authors.forename: Susan S
authors.initials: SS
authors.lastname: Jick
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Meier
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000150:complications* / Q000473:pathology; D003424:Crohn Disease / Q000150:complications* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012393:Rosacea / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D012720:Severity of Illness Index; D013557:Switzerland / Q000453:epidemiology