Clinical phenotypes of childhood food allergies based on immune mechanisms: A multicenter study

Background: Food allergies (FA) are an important public health concern that place a major burden on the lives of children and their families. The complex pathogenesis of FAs results in multisystemic and heterogenous clinical presentations. Objective: To evaluate, according to immune mechanisms, the characteristics and risk factors of childhood FA in Turkey. Methods: This descriptive multicenter study included 1248 children with FA, aged < 18 years,, who were evaluated by pediatric allergists in 26 different centers. Results: Immune mechanisms of FA were immunoglobulin E (IgE) mediated in 71.8%, non-IgE mediated in 15.5%, and mixed IgE/non-IgE mediated in 12.7% of the patients. An episode of anaphylaxis had occurred in 17.6% of IgE-mediated FA. The most common food allergens were classified into five categories (in order of decreasing frequency): cow's milk, egg, tree nuts and/or peanut, wheat, and seafood. Allergies to cow's milk and egg declined significantly with age, whereas tree nuts and/or peanut allergies increased with age. The 0-2 year age group accounted for 62.5% of the cases. The most frequent cause of FA and food anaphylaxis was cow's milk before age 13 years and tree nuts and/or peanut during adolescence (ages 13-18 years). Compared with other phenotypes, male sex (odds ratio [OR] 1.486; p = 0.032), sibling(s) (OR 1.581; p = 0.021), and maternal atopy (OR 1.531; p = 0.045) increased the likelihood of IgE-mediated FA, whereas high household income (OR 1.862; p = 0.026) increased the likelihood of non-IgE-mediated FA in multivariate regression analysis. Conclusion: This study showed that the clinical findings of FA were highly variable, depending on age and underlying immune mechanism. Knowing the population characteristics will enable better management of FA in children.