Frequency of food allergies over time - longitudinal statistics from 1978-1988

The frequency of allergies to particular foods in adults has never been documented over time. Therefore, it is not possible to give evidence about a possible shift in the spectrum of food allergens over the years. There are periodic analyses of the patients of the Allergy Unit of the Department for Dermatology at the University Hospital of Zurich that were diagnosed with food allergies between 1978 - 1998. Detailed data about food allergens are taken from previous published data. In order to detect trends in food allergens, the yearly frequency of food, responsible for systemic allergic reactions among food allergic patients diagnosed in these publications, is calculated for the observation period. Between 1978 - 1982: 173, between 1983 1987: 229, between 1990 - 1994: 383 and in the year 1998: 87 patients have been evaluated to have a food allergy. Over the entire observation period of 20 years, celery root was the most frequent allergen. The frequency of carot allergy was stable, but - in respect to celery - over all relatively low. Since the 90s, a marked increase of the following food allergies can be observed: allergies to peanuts and soy, which are both "legumes", as well as to nuts (hazelnuts and almonds), exotic fruits (kiwis and bananas), and, in the year 1998, to crustaceans. The possible explanations for these findings, for example an increase of pollen allergies and, consequently, of pollen-associated food allergies (birch fruits vegetables nuts syndrome, mugwort celery spices syndrom), the "latex fruit syndrome", the fast advancing and globalization of the American fast food culture (peanuts), among others are discussed.