Racial Differences in Early Introduction of Solid foods, IgE and Incidence of Atopic Dermatitis and Wheeze

Abstract

and Incidence of Atopic Dermatitis and Wheeze C. L. M. Joseph, D. R. Ownby, S. L. Havstad, E. M. Zoratti, C. C. Johnson; Dept of Biostatistics and Research Epidemiology, Henry Ford Hospital & Health System, Detroit, MI, Medical College of Georgia, Augusta, GA, Section of Allergy & Clinical Immunology, Henry Ford Hospital & Health System, Detroit, MI. RATIONALE: African Americans have a higher prevalence of asthma and are known to introduce solid foods earlier than European Americans, which might play a role in risk for early atopic dermatitis (AD) and wheeze. We explored, by race, the relationship of early (<3 months) introduction of solid foods to incidence of AD and wheeze by 6 months, and infant IgE, using a diverse birth cohort known as WHEALS. METHODS: To date, of 724 infant with cord blood samples, 260 infants have 6-month interview data and IgE measures (always presented as geometric means) and 164 have follow up at 12 months. AD/wheeze was defined as mother’s report of physician-diagnosed eczema rash/wheeze. RESULTS: Mean age of cohort mothers was 29.4 years; 53% were African-American. Incidence of 6-month AD and wheeze, and 1-year wheeze, was 2.7%, 6.2%, and 8.0%, respectively, with no race differences. Early solid food, reported by 20.9% of African-Americans vs. 7.5% of European-Americans (p50.01), was a strong predictor of 6-month AD in African-Americans, relative risk (95% confidence interval)55.7(1.033.2), p50.05; but not in European-Americans, RR51.4(0.2-10.1), p50.77. The 6-month IgE was higher for European-Americans with AD than those without (IgE575.0 vs. 6.3, p50.003); but less so for AfricanAmericans (IgE515.8 vs. 8.0, p50.42). Having AD at 6-months increased risk of 1-year wheeze among African-Americans more so than for European-Americans (RR58.3(3.2-21.9), p<0.01 vs. 3.0(0.8-11.1), p50.10). Trends are sustained after adjusting for infant birthweight. CONCLUSIONS: Race modifies the associations of early solid foods to AD and of AD to prevalent/incident wheeze. Involvement of IgE may also differ by race. Funding: NIH