Anaphylaxis to buckwheat in an atopic child: a risk factor for severe allergy to nuts and seeds?

Common buckwheat (Fagopyrum esculentum) is known to cause severe anaphylactic reactions in adult individuals. However, type I allergy to buckwheat is rarely seen in children. We report on a 7-year-old boy who developed a grade III anaphylactic reaction after consumption of a cake containing buckwheat flour. Prior to this incident, the boy had developed severe allergic reactions to hazelnuts and suffered from an oral allergy syndrome to poppy seed. Analysis of the patient's IgE reactivity by immunoblotting experiments revealed that he was sensitized to members of the 2S albumin and 11S globulin protein families in buckwheat. Additionally, cross-reactivity was found between the 11S globulins in buckwheat, poppy and hazelnut. IgE inhibition experiments indicated that the 11S globulin in buckwheat was the initial sensitizing protein. We conclude that 11S globulins in buckwheat have the potential to induce IgE antibodies cross-reactive with 11S globulins in other, botanically unrelated foods and may induce anaphylactic reactions.