Does urticaria risk increase in patients with celiac disease? A large population-based cohort study.

Background: Case reports and smaller case-control studies suggest an association between celiac disease (CD) and urticaria but risk estimates have varied considerably across studies and as yet there are no studies on CD and the risk of future urticaria. Objective: To examine the association between CD and urticaria. Methods: We identified 28,900 patients with biopsy-verified CD (equal to Marsh stage 3) and compared them with 143,397 age-and sex-matched controls with regards to the risk of urticaria and chronic urticaria (duration >= 6 weeks). Hazard ratios (HRs) were estimated using a Cox regression model. Results: During follow-up, 453 patients with CD and no previous diagnosis of urticaria developed urticaria (expected n = 300) and 79 of these 453 had chronic urticaria (expected n = 41). The corresponding HRs were 1.51 for any urticaria (95% CI = 1.36-1.68) and 1.92 for chronic urticaria (95%CI = 1.48-2.48). The absolute risk for urticaria in CD was 140/100,000 person-years (excess risk = 47/100,000 person-years). Corresponding figures for chronic urticaria were 24/100,000 person-years and 12/100,000 person-years. Patients with CD were also at increased risk of having both urticaria (odds ratio, OR = 1.31; 95%CI = 1.12-1.52) and chronic urticaria (OR = 1.54; 95% CI = 1.08-2.18) prior to the CD diagnosis. Conclusion: This study suggests that CD is associated with urticaria, especially chronic urticaria.