Personal and parental nativity as risk factors for food sensitization

Background: Immigrants to developed countries have low rates of aeroallergen sensitization and asthma, but less is known about both food allergy and the role of parental immigration status.

Objective: We sought to evaluate the relationship between personal and parental nativity and the risk of food sensitization.

Methods: Three thousand five hundred fifty subjects less than 21 years old from the Nation Health and Examination Survey 2005-2006 were included. Odds ratios (ORs) were generated by using logistic regression, which adjusted for race/ethnicity, sex, age, and household income and accounted for the complex survey design. Nativity was classified as US-born or foreign-born, and the age of immigration was estimated. Head-of-household nativity was used as a proxy for parental nativity. Food sensitization was defined as at least 1 specific IgE level of 0.35 kU/L or greater to milk, egg, or peanut. Aeroallergen-specific sensitizations and the presence of asthma, allergic rhinitis, or eczema were also assessed.

Results: Compared with those born outside the United States (US), US-born children and adolescents had higher odds of sensitization to any food (OR, 2.05; 95% CI, 1.49-2.83; P < .001). Among the foreign-born group, those who arrived before 2 years of age had higher odds of food sensitization than those who arrived later (OR, 2.68; 95% CI, 1.19-6.08; P = .02). Within the US-born group, in contrast, children of immigrants were at the highest risk (OR, 1.53; 95% CI, 1.05-2.24; P = .02).

Conclusion: Although foreign-born children and adolescents are at lower risk of food sensitization compared with those born in the US, among those born in the US, the children of immigrants are at the highest risk.