Objective: To investigate variations in the prevalence of self reported symptoms, diagnosis, and treatment of asthma in 12-14 year old children. Design: Self completion questionnaire. Setting: Great Britain.

Background-Respiratory diseases are common in childhood and may lead to chronic disease in adult life; environmental factors probably play an important part in their causation. Methods-A survey of respiratory symptoms in children aged 12-14 years was conducted throughout Great Britain as part of the International Study of Asthma and Allergies in Childhood (ISAAC). Information was obtained on certain aspects of the home environment in order to assess their importance as risk factors. Results-The response rate was 79.3%, and 25 393 children in 93 schools participated. In a multiple regression analysis, wheeze was reported more often in nonmetropolitan areas and in association with active smoking, passive smoking, the presence of a furry pet, bottled gas, paraffin, and other unusual heating fuels; small regional diVerences persisted. Current smoking, previous smoking, and passive smoking accounted for 10.4%, 6.8%, and 6.5%, respectively, of wheezing in the past 12 months, and furry pets accounted for 5.0%. Cough and phlegm were associated with active and passive smoking and with the miscellaneous fuels; similar associations were found for rhinitis, but were less consistent for rhinitis occurring in spring and summer. Gas cooking showed little association with respiratory symptoms. Conclusions-Passive as well as active smoking is an important cause of respiratory symptoms in adolescence. Pets seem to increase the risk of wheeze and rhinitis, and fumes from certain unusual heating fuels may have adverse eVects. Home environment and geographical location have independent eVects on the prevalence of respiratory symptoms.

Objectives-To describe the prevalence of atopic symptoms in children throughout the UK. Method-A questionnaire survey of 12-14 year olds throughout England, Wales, Scotland, and the Scottish Islands using the international study of asthma and allergies in childhood (ISAAC) protocol. Results-A total of 27 507 (86%) children took part. Recent rhinoconjunctivitis was reported by 18.2%, with 6.2% reporting symptoms between March and September; 16.4% reported itchy flexural rash in the past 12 months. The prevalence of atopic symptoms was higher in girls and subjects born within the UK. The prevalence of severe wheeze was highest in subjects reporting perennial rhinoconjunctivitis, as opposed to summertime only symptoms. Winter rhinoconjunctivitis was associated with severe wheeze and severe flexural rash. One or more current symptoms were reported by 47.6% of all children and 4% reported all three symptoms. Conclusion-In general, geographical variations were small but the prevalence of symptoms was significantly higher in Scotland and northern England. The study demonstrates the importance of atopic diseases both in their own right and in association with asthma. (Arch Dis Child 1999;81:225-230) Keywords: international study of asthma and allergies in childhood; hay fever; eczema; epidemiology; atopic diseaseThe prevalence of childhood hay fever shows wide variation throughout the world, ranging from 1.4% to 39.7%.1 The literature suggests that the prevalence of atopy has increased throughout the UK over the past five decades. In terms of eczema, the national British birth cohort study showed a rise in prevalence from 5.1% in 6 year olds born in 1946 to 12.2% for children born in 1970 and assessed at 5 years of age, 2 whereas data from the Welsh study of 12 year olds by Burr et al showed a rise from 5% in 1973 to 16% in 1988. 3 Similarly, the prevalence of hay fever in the same Welsh study rose from 9% to 15% over the 15 year period, whereas for Scottish children Russell reported a rise over a 25 year period from 3.2% in 1964 to 12.7% in 1994. 4 5 Ross and Fleming examined general practice data, which showed that the prevalence of hay fever was maximal in the age group 5-14 years and did not show any significant diVerences in geographical distribution throughout England or Wales. 6 Prevalence studies in diVerent geographical areas are often diYcult to compare because of variations in methodology. In addition, the term atopy, meaning a predisposition to develop type I hypersensitivity demonstrated by skin prick testing and assay of IgE, is often used in relation to atopic diseases such as hay fever and eczema. Many of these diYculties have been overcome by the protocol developed for the international study of asthma and allergies in childhood (ISAAC), which standardises both methodology and terminology. The distribution of hay fever and eczema are of interest not only in their own right, but also as an indicator of the pattern of atopy, which contributes to the burden of asthma. The literature demons...