IgE-mediated food allergies including oral allergy syndrome in 383 patients

383 predominantly adult patients (66.4% females, 33.6% males) with proved IgE-mediated food allergies (FA), including the oral allergy syndrome (OAS), were seen at the Allergy Unit of the Department of Dermatology in Zurich during the years 1990 - 1994. 63.2% of them had additional manifestations, predominantly a pollen allergy (60.3%). The FA manifested earlier in males (36.4% before 20 years old) than in females (17.7%). The organ manifestation of symptoms of FA was most often the skin (60%) with urticaria and angioedema and the oro-gastrointestinal tract (60%), if the OAS was included. 40% had respiratory symptoms (rhinitis, asthma) and 7.6% symptoms of the cardiovascular system (anaphylactic shock). Usually, the patients showed involvement of two or more organs. 44.4% had exclusively skin symptoms, 28.7% isolated OAS and 9.1% isolated gastrointestinal manifestations. Only 6.3% had chronic symptoms of a FA, the most common symptomatology was acute (30.5%) or recurrent (63.2%). Hazelnut (36.8%), celery (celery tuber or celeriac) (36.3%), apple (25.6%) and carrot (24.8%) were found to be the most frequent food allergens: hazelnut and apple elicited mostly an GAS, whereas celery caused generalized symptoms such as acute urticaria, asthma or anaphylactic shock. These food allergens belong to the so-called pollen-associated food allergens with sensitization mainly to birch. but also to mugwort pollens. Among the food non cross-reacting with pollens, an allergy was seen to peanut (12.8%), soja (9.1%), milk(10.7%), fish (9.7%), hen's egg (5.7%) and beef meat (2.9%). These observations confirm again that in adults the type I allergic reactions to plant-derived food is commonly by a consequence of primary aero-sensitization to pollen allergens. A primary ingestive sensitization in non-atopic people is rare in adults.