Phenotypic patterns of allergic comorbidity and associated health outcomes in children and adolescents: A population-based latent class study.

Purpose

Childhood allergic diseases often coexist, but phenotype-based evidence that includes food and drug allergy remains limited. The study aimed to derive potential allergic comorbidity phenotypes across five allergic diseases (eczema, rhinitis, asthma, food allergy, and drug allergy) and examine associations between identified phenotypic clusters and associated health outcomes in children and adolescents.

Methods

In this population-based cross-sectional study, 18,371 children and adolescents aged 3-14 years were enrolled from Beijing and Tangshan. Parent-reported physician diagnoses of eczema, rhinitis, and asthma, together with questionnaire-based food and drug allergy, were analyzed using latent class analysis (LCA). Multinomial and binary logistic regression models were used to identify factors associated with allergic phenotype membership and to assess associations between phenotype membership and related health outcomes, respectively.

Results

Three phenotypes were identified via LCA: low-allergy (13,505, 73.5%), rhinitis-dominant (3147, 17.1%), and multi-allergic (1719, 9.4%). Female sex, higher maternal education, middle household income, and shorter outdoor time were associated with significantly higher odds of both rhinitis-dominant and multi-allergic phenotypes. Early-life factors were mainly associated with the rhinitis-dominant phenotype. Longer sitting time and 1-2/week fast-food intake were associated with the multi-allergic phenotype. Compared with the low-allergy phenotype, rhinitis-dominant and multi-allergic phenotypes showed higher odds of upper respiratory infections (adjusted odds ratio: 4.40 and 3.48) and lower respiratory infections (2.49 and 2.57). Associations with dental caries were relatively weak. Sensitivity analyses supported the respiratory infection findings.

Conclusions

Three distinct allergic comorbidity phenotypes were identified in Chinese children aged 3-14 years, with two adverse phenotypes (rhinitis-dominant and multi-allergic) sharing lifestyle correlates yet differing in early-life exposure associations. Importantly, both phenotypes were independently associated with a higher likelihood of respiratory infections.