Eosinophilic Oesophagitis Beyond the Oesophagus: High Prevalence of Chronic Rhinosinusitis‐Type Symptoms and Their Impact on Symptom Severity in Swiss <scp>EoE</scp> Cohort Study Patients

BACKGROUND: Both eosinophilic oesophagitis (EoE) and chronic rhinosinusitis (CRS) are type 2 inflammatory conditions sharing pathogenic mechanisms, therapeutic responses and atopic associations. Data on the prevalence of CRS in EoE patients is missing. AIMS: Our aim was to assess the prevalence of CRS-type symptoms in EoE patients, the quality of life and shared characteristics of patients with both diseases. METHODS: We assessed the point prevalence of CRS in Swiss Eosinophilic Esophagitis Cohort Study patients using a validated screening questionnaire comprising four symptom-based diagnostic criteria. CRS was defined based on symptoms only (definition A) and including self-reported CRS diagnosis by a physician (definition B). Point prevalence was tested against population prevalence using two-sided binomial tests. Secondary outcomes were compared between patients with and without CRS. Multivariable logistic regression models were built to adjust for confounders. RESULTS: 211 patients (54%) answered our questionnaire. Prevalence of CRS-type symptoms was 21.8% (definition A) or 25.1% (definition B), compared to 8.71% in the general population (p < 0.0001). CRS status was associated with increased EoE symptom severity. This association persisted after adjustment in multivariable logistic models, most consistently under definition A. 25% reported that their CRS symptoms were more debilitating than their EoE symptoms. CONCLUSION: CRS-type symptoms are two- to three times more prevalent in EoE patients than in the general population and substantially impact quality of life. Our findings indicate that CRS may be under-diagnosed in EoE and support routine CRS screening in EoE patients and cross-speciality collaboration, particularly as both conditions benefit from therapeutic strategies targeting type 2 inflammation.