Risk factors for allergic rhinitis in children: an umbrella review of systematic review and meta-analysis

BACKGROUND: This study evaluates the quality of study design, potential biases, and evidence strength for childhood risk factors associated with allergic rhinitis (AR), while summarizing the key identified factors. METHODS: The protocol for this review was registered in PROSPERO (CRD420251248436). Relevant literature was systematically retrieved from PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews, covering the period from inception to May 2025. Methodological quality and evidence certainty were independently evaluated using AMSTAR and GRADE. RESULTS: This review identified 75 risk factors: 22 were linked to a higher risk of AR in children, 7 were protective, and 46 showed insufficient evidence to determine an association. Overall, evidence quality was low or very low, with only one factor supported by moderate-quality evidence. Key findings indicate that early-life antibiotic use, cesarean section, smoking during pregnancy, air pollution, ADHD diagnosis, ASD diagnosis, Kawasaki disease and maternal OCP exposure were associated with higher risk, while pet exposure, raw milk and fish consumption, birth order ≥ 2, and number of siblings ≥ 2 are associated with reduced risk. CONCLUSION: This first umbrella review systematically compiles all available meta-analytic data on pediatric AR risk factors, offering a provisional evidence map that prioritizes candidate modifiable targets for future research. Earlylife food sensitization is the only factor with moderate certainty. However, the generally low certainty of evidence underscores an urgent need for more rigorous and standardized primary studies and meta-analyses to strengthen the foundation for clinical and public health interventions. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD420251248436.