Rising incidence and prevalence of adult eosinophilic esophagitis in midwestern Spain (2007-2016).

Objectives: Epidemiologic studies on eosinophilic esophagitis (EoE) are scarce and patient responders to proton pump inhibitor (PPI) therapy have usually been excluded. We aimed to evaluate population-based incidence rates, prevalence and trends in adult EoE over the past decade, including responders to PPI therapy.

Methods: We conducted an analysis of a prospectively established case registry in the health area of Cáceres, located in midwestern Spain. From the first EoE case diagnosed in 2007, endoscopy and pathology reports up to December 2016 were manually reviewed. A baseline diagnosis of EoE was confirmed upon symptoms of esophageal dysfunction (dysphagia/food impaction) and esophageal eosinophilia ≥ 15 eos/HPF. All patients were re-evaluated on PPI therapy during follow-up.

Results: A total of 137 patients were diagnosed with EoE during the study period, of whom 63 (46%) achieved clinicohistologic remission on PPI therapy. The prevalence of autoimmune disorders was low. Mean incidence rate was 8.09 new cases/100,000 inhabitants/year, increasing to 9.95 during the last lustrum and peaking in 2016 with 13.7. This trend coincided with late declining of esophageal biopsies rate. Overall prevalence in 2016 was 81.73 patients/100,000 inhabitants, with the highest prevalence in males between age 35 and 44 years (273 cases/100,000). No seasonal variation was observed in the diagnosis of EoE (53% during pollen season vs. 47%, = 0.4).

Conclusions: In midwestern Spain, incidence (13.7 cases/100,000 inhabitants/year) and prevalence (81.73 patients/100,000 inhabitants) in 2016 have grown remarkably in just one decade, coming closer to those figures recently reported for Crohn's disease in Spain.