262. EOSINOPHILIC ESOPHAGITIS: A SEVEN YEAR ANALYSIS OF EPIDEMIOLOGY IN A UNITED KINGDOM COUNTY

Abstract Background Eosinophilic Esophagitis (EoE) is growing in incidence internationally. It is an immune-mediated disease that is characterised by esophageal mucosal eosinophilia and esophageal dysfunction. Awareness of EoE is also crucial for Esophagogastric surgeons as symptoms may mimic reflux disease or neoplasia, key considerations for an accurate differential diagnosis. Presently, there are no incidence estimates of EoE in the adult population in the UK. This study seeks to establish a cohort of EoE patients in Norfolk, a county in the East of England region, and to describe the incidence, characteristics, and diagnostic features of affected patients in both the adult and paediatric populations. Methods A retrospective analysis was performed of a prospectively maintained pathology database servicing a population of 761,000 persons in Norfolk. All newly diagnosed cases of EoE across a seven-year period between January 2017 and December 2023 were identified. Patients included for analysis had a histological diagnosis of EoE with >15 eosinophils/hpf and symptoms of oesophageal dysfunction. Patient electronic health care records were reviewed for histology reports, endoscopic findings, and clinical history. The primary outcome was incidence of EoE within the county. Secondary outcomes assessed included: patient characteristics; allergy and atopy history; endoscopic features, biopsy protocol and referral indication. Results 187 (median age 43 (4-85) years, Male: Female (126:61)) new cases of EoE were identified, of whom eight were in the paediatric age group of ≤16 years. The average annual incidence of EoE was 4.29 [95% CI 2.92, 5.66] and 0.89 [95% CI 0, 1.39] per 100,000 person/years in adult and paediatric groups respectively, with a significantly higher incidence in adults (RR 4.86 (95% CI [2.39 – 9.85] P<0.005) (Figure 1). The most common referral indications for endoscopy were dysphagia (80.7%) and food bolus obstruction episodes (25.1%). The most common endoscopic feature of EoE was circular rings (49.2%). Conclusion This is the first study reporting incidence of EoE in the UK adult population. There was a significantly greater incidence of EoE in adults compared to the paediatric population. However, there was no significant change in incidence of EoE in either group over the study period. Incidence estimates identified are similar to those reported in other European populations. Importantly 18.2% of patients had normal appearance of oesophagus on endoscopy, which reinforces the need to take oesophageal biopsies where there is clinical suspicion. Ideally, prospective registry data is needed for a comprehensive characterisation of incidence and prevalence of EoE.