[Asthma and allergic diseases in Sweden]

Until recently the prevalence of asthma in Sweden was assessed to be 2-3 per cent. An increase in the prevalence of asthma and allergic rhinitis was noted among new conscripts undergoing health work-ups prior to military service with the most marked increase in northern Sweden, were 5 per cent of conscripts were reported to have asthma. In southern Sweden the prevalence remained about 2 per cent. More recent questionnaire studies in mid- and southern Sweden have reported similar rates of respiratory symptoms and use of anti-asthmatic drugs as in northern Sweden, suggesting that there may be no difference in asthma prevalence between the north and the south of the country. The exact prevalence of allergic diseases among Swedish adults is still not clear, but 40 per cent of adults in northern Sweden report that they often have wheezing in the chest, attacks of breathlessness, longstanding cough or sputum production. In questionnaire studies among children about 40 per cent of respondents have reported that they had asthma, allergic rhinitis or other type of hypersensitivity. The absence of generally accepted diagnostic criteria for asthma and allergic disorders in epidemiological studies makes comparison of prevalence difficult. It is thus not possible to be sure that the prevalence of asthma and allergic disorders in Sweden has recently increased. Risk factors for the development of asthma and allergic disorders are under study in Sweden. Several studies report an association in children between urban living and allergic disorders.