Prior hospital‐based infection and risk of eosinophilic esophagitis in a Swedish nationwide case‐control study

BACKGROUND AND AIMS: Eosinophilic esophagitis (EoE) is an increasingly common, largely food allergen‐driven disease characterized by dysphagia. Prior infections are known to associate with other loss of tolerance diseases such as autoimmunity. We aimed to determine if antecedent infection was associated with later EoE development. METHODS: We performed a case‐control study of all patients with biopsy‐verified EoE diagnosed between 2000 and 2017 in Sweden (n = 1587) and matched to 5 general population controls (n = 7660). Cases were identified using histopathology codes from the Epidemiology Strengthened by histopathology Reports in Sweden study, a validated cohort of gastrointestinal pathology reports from all 28 pathology centers in Sweden. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals for antecedent infections from patients seen at hospital‐based outpatient clinics or inpatients. In secondary analyses, we compared EoE patients with their full siblings to further reduce residual confounding. RESULTS: 564 (35.7%) EoE patients and 1793 (23.4%) matched controls had an earlier record of infection. This corresponded to a 2‐fold increased risk of infections in EoE patients (OR 2.01; 95%CI: 1.78–2.27). ORs for earlier gastrointestinal or respiratory infection were 2.73 (n = 128 EoE, 268 control; 95%CI: 2.17–3.41) and 1.89 (n = 305 EoE, 960 control; 95%CI: 1.63–2.20), respectively. Having an EoE diagnosis was linked to a 3.39‐fold increased odds of sepsis (n = 14 EoE, 21 control; 95%CI: 1.68–6.65). Individuals with EoE were also more likely to have had an infection compared to their non‐EoE siblings (n = 427 EoE, 593 control; OR = 1.57; 95%CI = 1.30–1.89). CONCLUSION: In this nationwide cohort study, prior infection, was associated with subsequent EoE. Risks were particularly high after sepsis, and gastrointestinal or respiratory infections.