Prevalence of sensitization to food allergens in adult Swedes Eythor Bjo¨rnsson, MD,PhD*; Christer Janson, MD,PhD*; Peter Plaschke, MD†; Eva Norrman, MD‡; and Olof Sjo¨berg, MD, PhD§ Background: The results from a population study on respiratory symptoms and bronchial hyperresponsiveness in relation to symptoms of food intolerance and sensitization to food allergens are reported. Methods: The study included 1,812 men and women, aged 20 to 44 years and residents in three areas of Sweden who participated in the European Community Respiratory Health Survey. The prevalence of IgE sensitization to egg white, fish, wheat, peanut, soy,and milk was assayed by CAP-RAST and the prevalence of symptoms of food intolerance was determined by a standardized questionnaire. Results: The study group included a random sample of 1,397 subjects from the general population at the three centers. Of these, 85 (6%) had specific IgE antibodies to one of the food allergens and 345 (25%) reported symptoms of food intolerance. After enrichment with subjects suffering from symptoms of asthma, the sample included a total of 1,812 individuals of which 144 subjects had specific IgE antibodies to one or more of the food allergens studied. Of these 144, 52% reported food intolerance but only 16% related the symptoms to any of the food allergens in the panel. Sensitization to food allergens was more common in atopic subjects, subjects reporting current asthma, and subjects with bronchial hyperresponsiveness (P ⬍ .001).These associations remained significant after adjustment for the degree of allergic sensitization, whether defined as the number of positive skin prick tests or as total serum IgE levels. Conclusions: Although sensitization to food allergens is not uncommon in adults, the correlation to specific symptoms of food intolerance is weak. Sensitization to food allergens may have special relevance to asthma and bronchial hyperresponsiveness. Ann Allergy Asthma Immunol 1996;77:327–32. INTRODUCTION Adverse reactions to food are com- mon.Population studies suggest that 12% to 20% of the adult population in Western countries experience symp- toms of food intolerance. 1,2 The causes of these symptoms comprise a heter- ogenous group of disorders 3 and,al- though there is some confusion regard- ing terminology, the term food allergy has usually been reserved for reactions that are thought to be IgE mediated. In the diagnostic work-up of sus- pected food allergy, skin prick tests, radioallergosorbent tests (RAST) and, subsequently, foodchallengeswith suspected agents, are often performed. With these procedures, food allergy can be confirmed in 1% to 3% of the population. 2,4 Foods that are often implicated in food allergies include eggs, milk, nuts, wheat, soy,and fish. 5 Sensitization to these agents is usually acquired during childhood and the duration of clinical symptoms can vary depending on the allergen; 50% to 90% of symptoms caused by eggs, milk,and soybeans disappear within 3 to 5 years. 6 When sensitization occurs after the age of 10 years,fruits and vegetables appear to be the main causative agents. 7 Reportsindicate that food allergy may induceacuteasthma 8 but the mechanisms by which this is triggered are obscure. James etal 9 found that airway symptoms were common after food challenge in atopic children but studies of the effect of food challenges on bronchial hyperresponsiveness are contradictory. 10,11 We have used the opportunity pro- vided by the participation of three Swedish centers in the European Com- munity Respiratory Health Survey to address two aspects of food-related ill- nesses. First,the prevalence of food allergen sensitization and food intoler- ance symptoms in Sweden and, sec- ond,the possibleinfluenceof food sensitization upon the expression of asthma and bronchial hyperresponsive- ness. MATERIAL AND METHODS The European Community Respiratory HealthSurvey 12 was conducted in three areas of Sweden in 1991 to 1992. Thethreecenterscomprisedfrom north to south: the southern and west- ern parts of the county of Va¨sterbotten (Umeå and Lycksele health care dis- tricts),the municipality of Uppsala, and the island of Hisingen a part of Go¨teborg. Demographic characteris- This study was made possible by grants from The Swedish Heart & Lung Foundation, The Swedish Medical Research Council, The Swed- ish Association against Asthma and Allergy, The Association against Asthma and Allergy in Upp- sala,The Herman Kreftings Foundation, The BrorHjerpstedts Foundation and The County Councilof Uppsala. The reagents for the IgE analysis were kindly supplied by Pharmacia Di- agnostics, Pharmacia, Uppsala, Sweden. * Department of Lung Medicine and Asthma Research Centre, Akademiska sjukhuset, Upp- sala, Sweden. † Asthma and Allergy Research Centre, Sahl- gren’s Hospital, University of Go¨teborg, Go¨te- borg,Sweden. ‡ Department of Pulmonary Medicine and Allergology, University Hospital of Northern Sweden, Umeå, Sweden. § Department of ClinicalImmunology and Transfusion Medicine, Akademiska sjukhuset, Uppsala, Sweden. Received for publication November 3, 1995. Accepted for publication in revised form Feb- ruary 15, 1996. VOLUME 77,OCTOBER,1996 327