I In nt te er rn na at ti io on na al l s st tu ud dy y o of f a as st th hm ma a a an nd d a al ll le er rg gi ie es s i in n c ch hi il ld dh ho oo od d ( (I ISIts specific aims are: 1) to describe the prevalence and severity of asthma, rhinitis and eczema in children living in different centres, and to make comparisons within and between countries; 2) to obtain baseline measures for assessment of future trends in the prevalence and severity of these diseases; and 3) to provide a framework for further aetiological research into genetic, lifestyle, environmental, and medical care factors affecting these diseases.The ISAAC design comprises three phases. Phase 1 uses core questionnaires designed to assess the prevalence and severity of asthma and allergic disease in defined populations. Phase 2 will investigate possible aetiological factors, particularly those suggested by the findings of Phase 1. Phase 3 will be a repetition of Phase 1 to assess trends in prevalence.

The level of agreement between 14 physicians as to what constitutes a case of atopic dermatitis was tested on 15 selected patients with a range of diagnoses. Between-observer agreement was good, with a mean pair agreement index (P0) of 0.94, and a chance corrected index (kappa) of 0.78. Between-observer agreement in the recording of 18 separate physical signs of atopic dermatitis was then tested by asking the 14 physicians to note the presence or absence of each sign in a different group of patients to those seen in the first part of the exercise. Substantial between-observer agreement (kappa > 0.61) was only present for truncal dermatitis. Most signs showed only fair to moderate agreement (kappa 0.21-0.60), and some signs, such as keratosis pilaris, xerosis, orbital pigmentation, fine hair, and extensor dermatitis, showed poor agreement (kappa 0.01-0.20). The findings were similar when the responses of two independent observers from the national study outlined in Paper I were compared for each sign. Within-observer variation for the recording of physical signs was substantially better than between-observer variation. Physicians interested in atopic dermatitis agree reasonably well on what constitutes a typical case of atopic dermatitis. Between-observer variation with regard to some physical signs of atopic dermatitis is of a magnitude which argues against their continued use in clinical and epidemiological studies.

Background The increasing prevalence of asthma and allergy might be related to diet, particularly in Western countries. A study was undertaken to assess the association between dietary factors, asthma and allergy in a large international study including objective measurements of atopy. Methods Between 1995 and 2005, cross-sectional studies were performed in 29 centres in 20 countries. Parental questionnaires were used to collect information on allergic diseases and exposure factors and data from 50 004 randomly selected schoolchildren (8e12 years, 29 579 with skin prick testing) were analysed. Random effect models for meta-analysis were applied to calculate combined ORs. Results Fruit intake was associated with a low prevalence of current wheeze in affluent (OR adj 0.86, 95% CI 0.73 to 1.02) and non-affluent countries (OR adj 0.71, 95% CI 0.57 to 0.88). Consumption of fish in affluent countries (OR adj 0.85, 95% CI 0.74 to 0.97) and of cooked green vegetables in non-affluent countries (OR adj 0.78, 95% CI 0.65 to 0.95) was associated with a lower prevalence of current wheeze.