Allergy burden score and lung function impairment in children with asthma: a dose-response cross-sectional study

Children with asthma commonly present with multiple allergic comorbidities; however, the quantitative dose-response relationship between cumulative allergic burden and lung function has not been established in pediatric populations. This retrospective cross-sectional study included 264 treatment-naive children with asthma aged 4-16 years. An allergy burden score (ABS) was constructed using a cumulative disease count strategy incorporating allergic rhinitis, atopic dermatitis, food allergy, drug allergy, and family history of allergic disease. Multivariable linear regression and restricted cubic spline (RCS) analyses assessed dose-response relationships between ABS and FEV₁% predicted. Bootstrap-based statistical decomposition examined the contribution of type 2 inflammatory markers, and logistic regression assessed the odds of lung function abnormality. In the fully adjusted model, each 1-point increase in ABS was associated with a 3.03% decrease in FEV₁% predicted (95% CI: - 3.77 to - 2.29; P < 0.001). RCS analysis indicated significant nonlinearity (P for nonlinearity < 0.001), with accelerated decrease at ABS ≥ 3. Type 2 inflammatory markers accounted for only 2.7% of the statistically decomposed total association. Each 1-point increase in ABS was associated with 43% higher odds of lung function abnormality (adjusted OR = 1.43, 95% CI: 1.07-1.94).

A dose-response association exists between cumulative allergic comorbidity burden and lung function impairment in treatment-naive children with asthma. Peripheral type 2 inflammatory markers explain only a small proportion of this association, suggesting additional contributing mechanisms. The ABS may warrant further evaluation as a simple clinical indicator for identifying children with greater lung function impairment, pending prospective multicenter validation.

Not applicable. As a retrospective cross-sectional study, this research analyzed existing medical records without prospective assignment of interventions by the research team, and therefore does not meet the WHO criteria for clinical trial registration.

• Allergic comorbidities are prevalent in children with asthma and associated with worse clinical outcomes. The quantitative dose-response relationship between cumulative allergic burden and lung function has not been established in pediatric populations.

• Each 1-point increase in the Allergy Burden Score (ABS) was associated with a 3.03% decrease in FEV1% predicted, with a nonlinear threshold effect at ABS ≥ 3. Type 2 inflammatory markers collectively accounted for only 2.7% of the total association, suggesting that mechanisms beyond peripheral type 2 inflammation may be involved.