Soja in der veganen Ernährung - Lifestyleprodukte mit Gefahrenpotenzial für Birkenpollenallergiker?

About 10% of birch pollen allergic subjects have been reported to suffer from soy allergy, typically in form of an oral allergy syndrome. We report about 4 patients (1 male, 3 female, 50-72 years) with primary birch pollen allergy, who developed severe allergic reactions after intake of soy milk or soy drink. These patients suffered from allergic rhinoconjunctivitis in spring and from other pollen-associated food allergies. Skin prick tests to soy products were positive. In 3 out of 4 patients the soy allergy was demonstrated only by specific IgE to the birch pollen homologous PR-10 protein Gly m 4, but not to the total soy extract (<0,35KU/l). In one patient with previous tolerance to all soy products the soy allergy was only detected by the oral provocation testing. All patients developed secondary birch pollen-associated severe reactions to soy after intake of large amounts of unprocessed soy products (soy milk or soy drink). This is a risk for birch pollen allergic subjects with IgE-mediated allergies to both the birch pollen allergen Bet v 1 and to its homologous Gly m 4 in the soybean due to cross reaction.