Natural history of food allergy in infants and children in Israel

Background: Knowledge about the natural history of food allergy, especially sesame, is scarce. Objective: To follow the natural history of food allergies in Israel, particularly of sesame allergy. Methods: The Survey was conducted based on clinical records and a detailed questionnaire of children diagnosed as having food allergy. Results: We found 234 children with suspected food allergy. Testing detected 283 allergies in 180 patients (77%) with confirmed diagnosis. The most common allergies were to cow's milk (n = 125), eggs (n = 71), sesame (n = 30), and soy (n 23). Of those with milk allergy, 69% were IgE mediated (group 1) and 31% were non-IgE mediated (group 2). Group I was more likely to have an atopic background than was group 2 (P =.003), whereas group 2 was more likely to have resolution of the allergy (35 of 39 [90%] in group 2 compared with only 32 of 86 [37%] in group 1, P <.001). Allergy to soy was found in 23 children, of whom 87% manifested with gastrointestinal symptoms and 2 1 (91%) were also allergic to cow's milk. In 19 children (83%), the allergy resolved. Thirty children had allergy to sesame, and 73% of them had an atopic background. The allergy resolved in only 9 of these patients (30%) at a mean age of 2.8 years. Conclusions: The distribution of food allergens in Israel differs from that in other countries. Non-IgE-mediated food allergy and particularly milk and soy allergy were likely to resolve completely with time. Sesame allergy was 1 of the most frequent in this cohort, was usually IgE mediated, and tended to resolve in only a few patients.