60 children aged 3 months to 5 years (mean age 2 years) with early onset symptoms (cutaneous, respiratory or gastrointestinal) after ingestion of cow's milk, egg or fish, were investigated with skin prick tests, dosage of total IgE and specific IgE against these 3 food antigens. The case finding criteria used was positive elimination and challenge tests with the offending foods. In those instances in which intolerance to more than one food was suspected, cow's milk, egg and fish were reintroduced separately after remissions of symptoms with food exclusion. Specific IgE (Phadebas RAST) against the offending foods were found in 70% of cases, with early onset symptoms. RAST higher than 0.35 PRU were considered positive. Results showed that specific IgE antibodies in the serum tend to diminish with time: faster with cow's milk than with egg and specially fish. A sample of 15 children out of the 42 patients with positive RAST was followed up during a period of 3 years. 20 of them were treated with Nalcron, five with Ketotifen, and seventeen with both drugs. Eleven children were greatly improved or improved (74%) there was no clinical change in 4 (26%). Three groups can be considered: - One group with normal IgE levels after 2 years with no clinical symptoms/and no relapse after food challenge. - A second group with no symptom or mild symptoms with positive low levels of IgE. - The third group with resisting allergy to foods remains RAST positive. We conclude that frequency of positive RAST against food allergens is relatively high. High concentrations of IgE antibodies are almost exclusively seen in infants with an atopic disease.