Background

Relations between natural history of allergic sensitization and development of allergic diseases in childhood need to be clarified.

Objectives

This study aimed to identify patterns of allergic sensitization and of allergic morbidity during the first 8 years of life.

Methods

The study was conducted in the on-going population-based prospective Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. Sensitization profiles based on allergen-specific IgE levels measured twice in childhood (at ages 18 months and 8/9 years) and morbidity profiles based on symptoms, symptom severity, treatments, and lifetime doctor-diagnoses of asthma, allergic rhinitis, and atopic dermatitis and on lower respiratory infections before 2 years, were identified by unsupervised clustering.

Results

Five sensitization and 5 allergic morbidity patterns were established in 714 children. Thus, children not sensitized, or with isolated and low allergen-specific sensitization were grouped together (76.8%). Children strongly sensitized (?3.5 kUA/L) to house dust mite at 8/9 years (9.0%) had the highest risk of asthma and allergic rhinitis. Children early and persistently sensitized (4.1%) had an increased risk of atopic dermatitis and respiratory allergic diseases.

Conclusions

Allergic disease risk assessment should rely on earliness and multiplicity of sensitization, involved allergens, and allergen-specific IgE levels, and not only on allergen-specific sensitization considered as a dichotomous variable.