The age of eczema onset and multiple food allergies

Atopic dermatitis (AD) is the most common pediatric atopic disease and a risk factor for food allergy (FA) development. Children with AD are prone to developing allergic comorbidities. Its relationship with FA phenotype and timing of onset remains unclear.

To evaluate associations between AD presence and onset timing with FA-related outcomes and atopic comorbidities.

FORWARD is a longitudinal, multicenter study enrolling children younger than 12 years with physician-diagnosed FA between 2017 and 2024. Written informed consent was obtained. Data were collected from baseline survey and electronic medical records. Logistic regression models adjusted for demographic and socioeconomic factors assessed associations between AD with FA number, type of allergens, and atopic comorbidities.

Among 1309 children with physician-diagnosed FA, 77% reported history of AD, with 30.3% between 1 and 3 months, 50.2% at 4 to 12 months, and 19.5% after 12 months. Multiple FAs, asthma, and allergic rhinitis were each associated with higher odds of AD. Late-onset AD was associated to lower odds of multiple FAs compared with early onset AD (odds ratio 0.57, 95% CI 0.38-0.85), including lower odds of milk and egg allergies. Conversely, late-onset AD was associated with higher odds of asthma and allergic rhinitis.

Among children with FAs, 77% report a history of AD, with more than 80% of children with FA developed AD within the first year of life. Children with multiple FAs and those with allergies to milk and egg are more likely to develop AD on earlier age onset, whereas asthma and allergic rhinitis were associated with late-onset AD.