Allergic Rhinitis and Allergic Sensitization in Pediatric Otitis Media with Effusion: A Systematic Review and Meta-Analysis with Narrative Synthesis of Eustachian Tube Dysfunction

Background: Otitis media with effusion (OME) is a common pediatric middle-ear disorder with multifactorial pathogenesis. Allergic rhinitis and allergic sensitization have been proposed as contributing factors, but previous evidence remains heterogeneous. This systematic review and meta-analysis aimed to clarify the association between allergic rhinitis, allergic sensitization, and pediatric OME, while separately considering Eustachian tube dysfunction (ETD) and middle-ear dysfunction. Methods: A systematic search was conducted in PubMed/MEDLINE, Scopus, and the Cochrane Library. Observational studies evaluating allergic rhinitis, rhinitis, atopy, IgE sensitization, or allergy-related symptoms in relation to OME, ETD, abnormal tympanometry, or middle-ear dysfunction were considered eligible. Random-effects meta-analyses were performed separately for allergic rhinitis/rhinitis–OME and atopy/IgE sensitization–OME. ETD and middle-ear dysfunction outcomes were synthesized narratively because of methodological heterogeneity. Results: After removal of duplicates, 956 records were screened, 46 reports were assessed for eligibility, and 21 studies were included in the qualitative or narrative synthesis. Nine studies contributed to at least one pooled quantitative synthesis, while one additional birth-cohort study contributed adjusted estimates to the narrative sensitivity interpretation. Allergic rhinitis/rhinitis was significantly associated with OME in the primary meta-analysis (OR = 3.73, 95% CI 1.79–7.74, p < 0.001; I2 = 69.7%). The association remained significant in an expanded sensitivity analysis including one additional community-based study (OR = 3.46, 95% CI 1.92–6.23, p < 0.001; I2 = 63.7%). Atopy/IgE sensitization was also associated with OME (OR = 5.45, 95% CI 1.33–22.35, p = 0.018; I2 = 86.0%), although this analysis included only two studies. Most pooled estimates were derived from crude data and should therefore be interpreted as associations rather than causal effects. Conclusions: Allergic rhinitis/rhinitis and allergic sensitization are associated with increased odds of pediatric OME. However, the available evidence is mainly observational and heterogeneous. Allergic disease should be considered a potential contributing factor in selected pediatric OME phenotypes, rather than a universal or isolated cause. A phenotype-based approach involving both otolaryngology and allergy/immunology may be clinically useful.