Project Summary: Food allergy affects approximately 5-10% of young children, with highest incidence in the first year of life. Food allergy accounts for almost $25 billion per year in U.S. costs. Atopic dermatitis [AD] (also known as eczema) is a major risk factor for food allergy and other allergic diseases, and also has a significant intrinsic impact on child health. AD affects approximately 13% of U.S. children, of whom approximately 1/3 have moderate to severe disease. AD is a chronic disease characterized by skin barrier disruption and inflammation, with ongoing major effects on the quality of life of children and families. Currently, there is no reliable way to identify those infants destined to develop atopic disease who would benefit from targeted prevention strategies. The goal of this study is to establish a birth cohort that collects prenatal and early life environmental and bio-samples and rigorously phenotypes young children for food allergy and AD to identify prenatal and early life markers of high risk for food allergy and AD.