[Anaphylactic reaction to soy drink in three patients with birch pollen allergy].

Three patients presented with anaphylactic reactions to soy drink. Cross-reactivity of soy protein with birch pollen allergens was identified as the cause for their severe reactions. Because of the rising popularity of soy products and the large number of birch pollen allergic patients, allergologists will be increasingly confronted with these reactions in future. Patients with birch pollen allergy should avoid the intake of soy protein.