Original article Allergic diseases and atopic sensitization in children related to farming and anthroposophic lifestyle – the PARSIFAL study The prevalence of allergic asthma, allergic rhinoconjunc- tivitis and atopic eczema has increased markedly in recent decades, particularly among children (1, 2), although there is some recent evidence that the prevalence rates are stabilizing (3–5). The total costs for the major allergic diseases are estimated to 10 billion Euros for direct costs and 19 billion Euros for indirect costs in Europe (6). For adequate prevention it is important not only to identify risk factors, but also possible protective factors. The PARSIFAL (Prevention of Allergy Risk factors for Sensitization In children related to Farming and An- throposophic Lifestyle) project focuses on two groups of children who have shown a lower prevalence of atopic diseases and sensitization: farm children (7–11) and Background: The prevalence of allergic diseases has increased rapidly in recent decades, particularly in children. For adequate prevention it is important not only to identify risk factors, but also possible protective factors. The aim of this study was to compare the prevalence of allergic diseases and sensitization be- tween farm children, children in anthroposophic families, and reference children, with the aim to identify factors that may protect against allergic disease. Methods: The study was of cross-sectional design and included 14 893 children, aged 5–13 years, from farm families, anthroposophic families (recruited from Steiner schools) and reference children in Austria, Germany, the Netherlands, Sweden and Switzerland. A detailed questionnaire was completed and allergen- specific IgE was measured in blood. Results: Growing up on a farm was found to have a protective effect against all outcomes studied, both self-reported, such as rhinoconjunctivitis, wheezing, atopic eczema and asthma and sensitization (allergen specific IgE ‡0.35 kU/l). The adjusted odds ratio (OR) for current rhinoconjunctivitis symptoms was 0.50 (95% confidence interval (CI) 0.38–0.65) and for atopic sensitization 0.53 (95% CI 0.42–0.67) for the farm children compared to their references. The prevalence of allergic symptoms and sensitization was also lower among Steiner school children compared to reference children, but the difference was less pronounced and not as consistent between countries, adjusted OR for current rhinocon- junctivitis symptoms was 0.69 (95% CI 0.56–0.86) and for atopic sensitization 0.73 (95% CI 0.58–0.92). Conclusions: This study indicates that growing up on a farm, and to a lesser extent leading an anthroposophic life style may confer protection from both sensitization and allergic diseases in childhood. T. AlfvØn 1 , C. Braun-Fahrländer 2 , B. Brunekreef 3 , E. von Mutius 4 , J. Riedler 5 , A. Scheynius 6 , M. van Hage 7 , M. Wickman 8 , M. R. Benz 4 , J. Budde 4 , K. B. Michels 9 , D. Schram 3 , E. Üblagger 10 , M. Waser 2 , G. Pershagen 1 , the PARSIFAL study group* 1 Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; 2 University of Basel, Institute for Social and Preventive Medicine, Basel, Switzerland; 3 Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; 4 Dr von Haunersche Kinderklinik, München, Germany; 5 Kinderspital Schwarzach, Schwarzach, Austria; 6 Department of Medicine, Clinical Allergy Research Unit, Karolinska Institutet and Hospital, Stockholm, Sweden; 7 Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska University Hospital, Stockholm, Sweden; 8 Unit for Environmental Medicine, Karolinska Hospital, Stockholm, Sweden; 9 Department of Epidemiology, Obstetrics and Gynecology Epidemiology Center, Brigham and Women's Hospital, Harvard Medical School, Harvard School of Public Health, Boston, MA, USA; 10 Department of Paediatric Pulmonology and Allergology, Children's Hospital, Salzburg, Austria *The PARSIFAL study group is given in Appendix. Key words: asthma; environment; epidemiology; paedi- atrics; rhinitis. Tobias AlfvØn Institute of Environmental Medicine Box 210 Karolinska Institutet SE-171 77 Stockholm Sweden Accepted for publication 30 May 2005 Allergy 2006: 61: 414–421 Copyright Ó Blackwell Munksgaard 2005 ALLERGY DOI: 10.1111/j.1398-9995.2005.00939.x 414