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Objective: To assess asthma among Brazilian pediatric population applying the International Study of Asthma and Allergies in Childhood (ISAAC), an internationally standardized and validated protocol. Data sources: ISAAC was conceived to maximize the value of epidemiologic studies on asthma and allergic diseases, establishing a standardized method (self-applicable written questionnaire and/or video questionnaire) capable to facilitate the international collaboration. Designed to be carried out in three successive and dependent phases, the ISAAC gathered a casuistic hitherto unimaginable in the world and in Brazil. This review included data gathered from ISAAC official Brazilian centers and others who used this method. Data synthesis: At the end of the first phase, it has been documented that the prevalence of asthma among Brazilian schoolchildren was the eighth among all centers participating all over the world. Few centers participated in the second phase and investigated possible etiological factors, especially those suggested by the first phase, and brought forth many conjectures. The third phase, repeated seven years later, assessed the evolutionary trend of asthma and allergic diseases prevalence in centers that participated simultaneously in phases I and III and in other centers not involved in phase I. Conclusions: In Brazil, the ISAAC study showed that asthma is a disease of high prevalence and impact in children and adolescents and should be seen as a Public Health problem. Important regional variations, not well understood yet, and several risk factors were found, which makes us wonder: is there only one or many asthmas in Brazil?

The aim of this study was to evaluate the prevalence of rhinitis-related symptoms among children living in different parts of Latin America (LA) considering all centers involved in ISAAC Phase Three (Ph3). 93,851 children (6-7 yr-old) from 35 centers in 14 LA countries and 165,917 adolescents (13-14 yr-old) from 56 centers in 17 LA countries were enrolled. The mean prevalence rate of current rhinoconjunctivitis was 12.7% and ranged from 5.5% in Rosario City (Argentina) to 21.2% in Caracas (Venezuela) for the schoolchildren. The mean prevalence rate of current rhinoconjunctivitis was 18.5% and ranged from 7.1% in Cuernavaca (México) to 45.1% in Asunción (Paraguay) for the adolescents. These indexes were among the higher observed during ISAAC Ph3. In general the prevalence of rhinitis-related symptoms was higher among the Spanish speaking centers. Environmental risk factors must be evaluated in order to explain the differences observed even in centers from the same country.

The prevalence of asthma, rhinitis and atopic eczema in Brazil varies considerably. Higher prevalence rates, especially of asthma and eczema, were found at centers located closer to the equator.

The objective of this study was to evaluate the role of rhinitis (R) and atopic eczema (E) on asthma severity among asthmatic (A) schoolchildren identified by the International Study of Asthma and Allergies in Childhood written questionnaire (WQ). WQ was applied to parents of 6-7-yr-old schoolchildren (SC, n=3033), and to adolescents (AD, 13-14 yr old, n=3487), living in Sao Paulo, Brazil. An affirmative response to 'has your child/have you had wheezing/whistling in the last year' identified those with A, and an affirmative response to 'the last 12 months has your child/have you had sneezing/runny/blocked nose when he/she you did not have a cold/flu?' identified those with R. Subjects with an affirmative response to 'has your child/have you had this itchy rash at any time in the past 12 months?' were identified as having E. Subjects who had R associated with A were identified as AR and those with A associated with R and E as ARE. A who had at least two affirmative responses to questions for asthma severity: speech disturbance, more than four acute attacks, sleep disturbance, and wheezing with exercise were defined as having severe asthma. 22.1% AD and 24.3% SC were identified as A; 47.1% of those AD and 42.0% SC had AR and 10.0% of those AD and 12.8% of SC had ARE. Considering ARE, AR and A groups, speech disturbance during an acute episode of asthma was significantly higher among ARE AD (20.0% vs. 11.5% vs. 8.7%, p<0.05), and ARE SC (22.1% vs. 13.9% vs. 10.5%, p<0.05) in comparison with A. Likewise, more than four acute attacks in the last year was significantly higher among ARE AD (24.0% vs. 14.0% vs. 10.5%, p<0.05) and ARE SC (32.6% vs. 19.4% vs. 12.8%, p<0.05) as the frequency of sleep disturbance due to wheezing, for AD (61.3% vs. 42.0% vs. 38.4%, p<0.05) and SC (77.9% vs. 67.3% vs. 58.4%, p<0.001) and for 'wheezing associated with exercise' for AD (72.0% vs. 47.5% vs. 39.9%, p<0.001) and SC (36.8% vs. 31.4% vs. 14.1%, p<0.001). Prevalence of severe asthma was higher among ARE AD (57.3% vs. 31.9% vs. 27.0%, p<0.05) and ARE SC (52.6% vs. 36.9% vs. 22.5%). In patients with A, the presence of R or E are risk factors for severe asthma, and both together (R and E) are a higher risk.