Pandemic-Associated Sensitization Patterns and Burden in Chinese Children with Allergic Rhinitis: A Retrospective Phase-Stratified Study.

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic and associated non-pharmaceutical interventions may have altered children's indoor, outdoor, and dietary exposures. However, phase-specific data on allergen sensitization patterns in pediatric allergic rhinitis (AR) remain limited.

Objective: To assess phase-specific changes in serum allergen-specific immunoglobulin E (sIgE) sensitization patterns, intensity, co-sensitization, and burden in children with AR in Eastern China.

Methods: We analyzed 12,702 children aged 0-18 years with clinically diagnosed AR who underwent sIgE testing for 19 inhalant and food allergens in Eastern China from 2018 to 2024. Sensitization was compared across pre-pandemic (2018-2019), lockdown (2020-2022), and post-lockdown (2023-2024) phases using Pearson's χ² -test or Fisher's exact test and multivariable logistic regression adjusted for age group, sex, and season. Strong sensitization was defined as sIgE ≥3.51 IU/mL, and co-sensitization as concurrent sensitization to both allergens in a pair.

Results: Compared with the pre-pandemic phase, the lockdown and post-lockdown phases showed divergent sensitization trajectories, with higher sensitization to several inhalant allergens and lower sensitization to selected food allergens, although selected seafood allergens increased in later phases. Post-lockdown, adjusted analyses showed higher odds for selected indoor, outdoor, and seafood allergens, while other allergens remained stable or showed non-monotonic patterns. Strong-positive responses, selected co-sensitization patterns, and ≥4 sensitizations were also more common post-lockdown.

Conclusion: Across the pre-pandemic, lockdown, and post-lockdown periods, children with AR showed divergent trajectories of inhalant and food allergen sensitization, as well as greater post-lockdown sensitization intensity and complexity. These findings reflect phase-specific associations rather than direct causal effects of the pandemic. They may help inform post-pandemic risk stratification in pediatric AR, with greater attention to inhalant allergen control and more cautious interpretation of food sIgE positivity in clinical context.