Allergic Rhinitis as an Independent Risk Factor for Pneumonia in Children: A Large-Scale Database Analysis

Background: While allergic rhinitis (AR) is linked to upper airway complications, its independent association with pneumonia, particularly after excluding asthma, remains insufficiently characterized in large pediatric populations. Objective: To evaluate the risk of pneumonia in children with AR and assess the independent effect of AR by accounting for asthma and other comorbidities. Methods: Using the TriNetX global research network, we conducted a retrospective cohort study of children aged 2–18 years newly diagnosed with AR. A control group without AR was matched 1:1 using propensity score matching (PSM) for demographics and comorbidities. The primary outcome was pneumonia incidence during 3–12 month and 1–3 year follow-up windows. Subgroup analyses were performed for non-asthmatic cohorts and regional networks (US and APAC). Results: Each cohort included 163,149 matched patients. Children with AR faced a significantly higher risk of pneumonia compared to controls at 3–12 months (HR 3.70; 95% CI 3.37–4.07) and 1–3 years (HR 2.98; 95% CI 2.77–3.20). Notably, in the non-asthmatic subgroup, the risk was even more pronounced (HR 4.56 at 3–12 months). Within the AR cohort, comorbid asthma further increased pneumonia risk (HR 1.54). Results remained consistent in sensitivity analyses using elevated IgE levels and across both US and APAC networks. Conclusion: Allergic rhinitis is a potent independent risk factor for pneumonia in children, regardless of asthma status. These findings underscore the importance of early AR management to potentially mitigate lower respiratory complications.