Epidemiology of food allergy/food intolerance in adults:: associations with other manifestations of atopy

Background: Food allergy and food intolerance (FA/FI) are believed to be frequent medical problems; however, information from epidemiologic studies in adults is scarce. The objective was to determine the frequency of FA/FI and allergic sensitization to food in a large adult sample. Furthermore. the associations between FA/FI and other outcomes of atopy were studied. Methods: Within a population-based, nested, case-control study, a standardized interview was performed to obtain detailed information on FA/FI and the history of atopic diseases. In addition, a skin prick test with 10 common food and nine aeroallergens was performed. Results: Overall, 20.8% of the 1537 Studied Subjects (50.4% female, age median 50 years) reported FA/FI (women 27.5%, men 14.0%; OR 2.35 CI 1.80 3.08). Nuts, fruits, and milk most frequently led to adverse effects. and the sites or manifestation were oral (42.9%), skin (28.7%), gastrointestinal (13.0%), systemic (3.2%), and multiple (12.2%). One-quarter of the subjects (25.1%) were sensitized to at least one food allergen in the prick test, with hazelnut ( 17.8%). celery (14.6%), and peanut (11.1%) accounting for most of the positive reactions. The corresponding frequency estimates for the representative Study base (n = 4178) were 15.5% for reported adverse reactions and 16.8% for allergic sensitization. Relevant concomitant sensitization to food and aeroallergens was observed. Food-allergic Subjects (positive history and sensitization to corresponding allergen) Suffered significantly more often from urticaria. asthma, atopic eczema. and especially hay fever (73.1%) than controls (3.0%). Furthermore, hay fever was treated significantly more often in subjects who Suffered from concomitant food allergy. Conclusions: FA/FI in adults is frequently reported and associated with other manifestations of atopy. Hay fever in conjunction with FA/FI tends to be clinically more severe since therapeutic needs are enhanced.