Food allergy is a matter of geography after all: sesame as a major cause of severe IgE-mediated food allergic reactions among infants and young children in Israel

Objective: To determine the prevalence, importance, and the order of frequency of IgE-mediated food allergens among infants and young children in Israel. Study design and patients: In a cross-sectional study, the prevalence of IgE-mediated food allergy was investigated in 9070 infants and young children (0-2 years) who were followed-up at 23 Family Health Centers (FHCs) in central Israel. Patients with suspected IgE-mediated food allergic reactions, were recruited for further evaluation (detailed questionnaire and skin-prick test (SPT)). Results: We identified 150 out of 9070 (1.7%) patients with suspected IgE-mediated food allergy. Among them, 102/150 (67%) [59 males, 43 females; mean age 10.3 months] completed a detailed questionnaire and underwent SPT. Evaluation revealed 131 positive SPTs in 78/102 (76.5%) patients. Twenty-seven positive SPTs in 18 patients were considered clinically irrelevant based on previous consumption of the relevant foods without clinical symptoms. Thus, there were 104 relevant positive SPTs in 78 patients. The overall prevalence of clinically relevant IgE-mediated food allergic reactions among these patients is estimated to be 1.2% (104/9070). The most common food allergens were egg, cow's milk, and sesame. Anaphylaxis was the presenting symptom in 14/78 (18%) including six sesame-induced cases. A history of other atopic diseases was reported in 27 (35%) patients. In addition, 22 (28%) had a history of atopy in first-degree family members. Conclusions: We found sesame to be a major cause of IgE-mediated food allergy in Israel. In fact, it is second only to cow's milk as a cause of anaphylaxis. We recommend that testing for food allergens be tailored to each community based on local experience and should include sesame in appropriate populations.