Association between acid‐suppressive drug use and atopic dermatitis in patients with upper gastrointestinal diseases: A population‐based retrospective cohort study

WHAT IS KNOWN AND OBJECTIVE Proton-pump inhibitors (PPIs) and histamine-2-receptor antagonists (H2RAs) are two of the most widely used acid-suppressive drugs (ASDs). Some studies have reported that prenatal ASD exposure may increase the risk of asthma and other allergic diseases. This study investigated the effects of ASDs on the risk of atopic dermatitis in patients with upper gastrointestinal diseases. METHODS This population-based retrospective cohort study used data of 289,850 patients with at least two diagnoses of upper gastrointestinal diseases (UGIDs) between 1 January 2001 and 31 December 2005, from Taiwan's National Health Insurance Research Database. The AD risks among ASD users and nonusers were compared. Differences in sociodemographic characteristics and potential covariates were examined. AD hazard ratios were estimated, and groups were compared using Cox proportional hazards regression analysis after adjustment for age, sex and other covariates. RESULTS AND DISCUSSION In total, 109,980 patients were included. The adjusted hazard ratio (HR) of AD risk in ASD users relative to that in nonusers was 1.52 (95% confidence interval [CI]: 1.40-1.64, p < 0.001). For a dose-effect sub-analysis, patients were divided into four groups based on their defined daily dose. ASDs dose-dependently affected the AD risk (p for trend <0.01). Furthermore, the adjusted HR of the AD risk among ASD nonusers was 2.30 (95% CI: 2.06-2.57) relative to that in the comparison group (ASD nonusers without UGIDs). Among patients with UGIDs, ASD users had a higher AD risk than ASD nonusers. A subgroup analysis revealed only H2RA use was associated with an increased AD risk (adjusted HR 1.70, 95% CI: 1.53-1.89, p < 0.001). WHAT IS NEW AND CONCLUSIONS These results indicate that the use of H2RAs was associated with an increased risk of AD among patients with UGIDs, and the increase in risk appeared to be dose-dependent. ASDs should be used only in situations where clear clinical benefits can be obtained.