Increasing incidence of eosinophilic esophagitis in Sweden: a nationwide population study.

Background: Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus associated with dysphagia and esophageal fibrosis. The incidence of EoE is not precisely known, and significant heterogeneity in study design and disease definition have led to widely variable estimates. Through the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study we performed a nationwide population-based study to estimate the incidence and temporal patterns of biopsy-verified EoE.

Methods: Between October 2015 and April 2017, we contacted all pathology departments in Sweden (n = 28) to obtain biopsy report data on EoE. To assure a high degree of completeness, we restricted the study to 2004-2015. We then calculated age-specific and age-standardized incidence rates.

Results: We identified 1412 incident EoE cases between 2004-2015. The overall age-standardized incidence rates of EoE in Sweden was 1.22 per 100,000 person-years. During the study period, there was a significant increase of 33% [95%CI = 31-36%] (P < 0.001) per year in EoE incidence, and in the last 3 years of follow-up (2013-2015) the incidence was 2.79 per 100,000 person-years. This corresponds to a lifetime risk of biopsy-verified EoE for men of 0.33% (1 in 295 men) and for women 0.12% (1 in 813 women). We observed an early peak of EoE disgnosed at age 15-19 years for both males and females, and a second peak in the late 30 s for males, and early 40 s for females. We noted a 3:1 male-to-female predominance, which did not significantly vary over time.

Conclusions: EoE seems to be increasing in Sweden, with an overall age-standardized incidence of EoE of 1.22 per 100,000 person-years in the last decade.