Urban Residency is Independently Associated With Allergic Phenotype and Inflammatory Changes in Eosinophilic Esophagitis

GOALS: To identify clinical features associated with geographic residency in patients with eosinophilic esophagitis (EoE). BACKGROUND: Prior studies on the geographic distribution of eosinophilic esophagitis (EoE) have focused on disease prevalence. Geographic and environmental factors may impact the clinical characteristics and phenotypes of EoE, although data remain limited. STUDY: This was a cross-sectional study of consecutive patients residing in Massachusetts with newly diagnosed EoE (≥15 eosinophils/hpf). Patients' residency settings were classified as urban or nonurban based on the 2020 US Census and residential zip codes. Clinical, endoscopic, and histologic variables were recorded. EoE patients in urban versus nonurban settings were compared using the student t test or the Fisher exact test for univariate analyses. Multivariable logistic regression was performed to identify the independent association between urban residency and comorbid atopic conditions, the inflammatory endotype, and the fibrostenotic endotype. RESULTS: Six hundred eighty-three EoE patients were included, with 136 (20.0%) urban and 547 (80%) nonurban residents. Urban patients had higher rates of atopy (63.2% vs. 51.8%, P=0.02), severe food/environmental allergies (17.7% vs. 8.3%, P=0.002), and inflammatory findings endoscopic (43.4% vs. 27.8%, P=0.0006). On multivariable analysis, atopy (OR=1.57, CI: 1.02-2.40, P=0.04), severe food/environmental allergies (OR=1.99, CI: 1.09-3.63, P=0.02), and inflammatory findings (OR=1.90, CI: 1.22-2.94, P=0.004) remained independently associated with urban residency. CONCLUSIONS: Urban residency is independently associated with severe food/environmental allergies and inflammatory endoscopic findings at EoE diagnosis, suggesting increased allergic phenotype and active inflammation at presentation. Allergen exposure, particularly indoors, and social determinants may be contributory factors. Environmental considerations, such as geographic residency, may impact EoE disease presentation, activity, and outcome.