ABSTRACT
There is no doubt that fruits and vegetables belong to the most important elicitors of food allergy in adults and adolescents. However, all food allergens that have been identified and characterized so far are natural molecules, i.e., proteins or glycoproteins. The overwhelming majority of hypersensitivity reactions against fruits and vegetables is highly associated with several pollen allergies. At the molecular level, this phenomenon is based on cross-reactions of human antibodies which are directed against pollen allergens. Cross-reactivity of allergen-specific antibodies is a well known phenomenon in food allergy. These cross-reactions often include phylogenetically unrelated species, for example birch and kiwi. In many cases, respiratory uptake of inhalant allergens is thought to be the causative factor for development of food hypersensitivities. Allergy to celery, carrot, and umbelliferous spices has originally been described as being mainly associated with mugwort pollen allergy.
