Beer-induced anaphylaxis: identification of allergens

Background: We report on a 21-year-old atopic woman who developed urticaria, angioedema of the face, and wheezy dyspnea shortly after drinking beer and after eating a corn-made snack. Methods: Skin prick tests and specific IgE determinations to beer ingredients and cereal extracts were performed. Immunoblotting inhibition assays were carried out to investigate possible common allergens shared by barley and malt with corn. Results: Skin prick tests and specific IgE measurements with beer, barley, malt, wheat, corn, rye, rice, and oat flour were positive. Ten pollen-allergic patients showed negative skin tests to beer. Double-blind, placebo-controlled, oral challenge tests with sodium metabisulfite and wheat flour were negative. Immunoblotting demonstrated several IgE-binding bands at 31–56 kDa in malt and barley extracts, and a major band at 38 kDa in the beer extract. Immunoblot inhibition assays showed that malt extract was able to inhibit most of the IgE-binding bands in wheat and corn extracts, whereas corn did not produce significant inhibition to barley and malt extracts. Conclusions: This patient developed type I hypersensitivity to barley/malt and corn. Although she also showed IgE reactivity to wheat and other cereals, no symptoms were elicited upon ingestion of these cereals, probably indicating latent sensitization to them.