[Molecular aspects of allergy to plant products. Part I. Class I and II allergens and crossreactivity of IgE antibodies].

Food allergies are adverse immunologic reactions that might be due to IgE--or none IgE-mediated immune mechanisms or mixed. One of the more common and typically most mild forms of IgE- mediated food allergy is the so-called oral allergy syndrome (OAS), although systemic symptoms after ingesting a particular fruit or vegetable can occur. Pollen food syndrome is the most common food allergy in adolescents and adults. It develops as a consequence of shared epitopes in the primary and tertiary structures of pollen and food allergens. The authors describe class I and class II allergens, as well as molecularly determined IgE-crossreactivity phenomenon. Also the problem of symptom-free consumed pollen-related food allergens, which might cause T cell-mediated late-phase skin reactions in patients with pollen allergy and atopic dermatitis, is taken up.