In 2184 young children aged 13-24 months with atopic dermatitis (SCORAD 5-59) serum IgE antibodies to a standard panel of food and inhalant allergens were assayed. The frequency of positive IgE responses (>0.35 kU/l) increased with greater severity of skin disease. A significant minority of infants had levels of IgE antibody to foods to suggest they were at risk of acute reaction to those foods (7% to hen's egg, 3% to cow's milk, 4% to peanut). Our findings indicate that the frequency of positive IgE responses is related to disease severity and suggest that differences in the time course of the development of IgE responses to food, which are at maximum prevalence within the first year of life, while inhalant allergies, are still developing between 1 and 2 yr and beyond.