International Study of Asthma and Allergies in Childhood (ISAAC): prevalence of asthma and asthma-related symptoms among Brazilian schoolchildren.

We have studied the prevalence of asthma and its symptoms using a standard written questionnaire (WQ) designed for the International Study of Asthma and Allergies in Children (ISAAC). The WQ (questions 1 through 8 related to asthma) was applied to 13,604 children aged 6-7 years from six Brazilian cities: Porto Alegre (South, N = 2,976), Curitiba (South, N = 1,664), S?o Paulo (Southeast, N = 3,005), Uberlandia (Southeast, N = 3,002), Itabira (Southeast, N = 1,551) and Recife (Northeast, N = 1,406). At the age of 13-14 years the WQ was applied to 20,554 schoolchildren living in Porto Alegre (South, N = 3,198), Curitiba (South, N = 3,008), S?o Paulo (Southeast, N = 3,008), Uberlandia (Southeast, N = 3,001), Itabira (Southeast, N = 2,134), Salvador (Northeast, N = 3,119) and Recife (Northeast, N = 3,086). The parents of the younger children answered the WQ, whereas the adolescents answered the questionnaire themselves. The response rates were 72% and 93% for the 6-7-year-old children and for the 13-14-year-old children, respectively. There was a slight predominance of male children in the population studied. In the group of 6-7-year-olds, the prevalence of physician diagnosed asthma was 7.3% for boys and 4.9% for girls: in the group of 13-14-year-olds the rates were 9.8% and 10.2%, respectively. Asthma severity was similar for both age groups, and wheezing following exercise was more frequent among the adolescents. In keeping with studies from other parts of the world, comparison between reported symptoms and diagnosed asthma revealed a significantly lower frequency of diagnosed asthma, suggesting that in the study population, asthma is underdiagnosed.     

Prevalence of Asthma and Asthma-Like Symptoms in Inner-City Schoolchildren

This study investigates the prevalence of asthma and asthma-related symptoms in New Orleans inner-city schoolchildren. A cross-sectional survey of 1535 elementary, middle, and high schoolchildren (aged 5-18) was conducted by using the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire. Lifetime prevalence of wheezing was 39.4%, and lifetime prevalence of asthma was 24.4%. Wheezing during the previous 12 months was reported by 25.7% of the sample. Twenty-one percent of respondents reported having one or more attacks of wheezing per year, with 5.6% reporting four or more attacks per year. Many participants reported sleep disturbance (15.4%), with 6.2% reporting sleep disturbance more than once a week. The 12-month rate of speech limitation due to asthma exacerbation was 6.6%. Exercise-induced asthma was reported by 16.9% of the students, and nocturnal cough (not associated with cold) was reported by 27.3%. Overall, boys reported higher rates of symptoms than girls, and younger children (aged 6-7) reported greater symptoms than older children (aged 13-14). These findings show that prevalence of asthma in this population is elevated and the ISAAC written questionnaire successfully identified inner-city children at risk for asthma in New Orleans.     

Exercise-Induced Asthma is Associated with Impaired Quality of Life Among Children with Asthma in Japan

BackgroundAsthma is the most common chronic diseases in school-aged children in Japan. It is important to consider health-related quality of life (QoL) among children with chronic diseases when treatment decisions are made.MethodsA school-based survey was conducted in randomly selected public schools in Tokyo by using a KINDL® questionnaire for evaluating QoL and the international study of asthma and allergy on childhood (ISAAC) questionnaire, which is designed for comparing the asthma prevalence in various countries, from May to June in 2005. We recruited approximately 10% of the total children 6–7-years-old and 13–14-years-old living in Tokyo for sampling.ResultsResponse rate of this questionnaire was 86% (22,645 children) in the 6–7-year-old group and 64% (12,879 children) in the 13–14-year-old group. Comparing asthmatics with non-asthmatics in the same age, QoL of children with asthma was significantly impaired. The severity of QoL of children with asthma was significantly impaired. QoL of children with exercise-induced asthma (EIA) were more significantly impaired than ones without EIA and showed lower scores in the categories of physical functioning, emotional and school activities than those without EIA. Of note, QoL was more impaired in the EIA-positive group among severe asthmatics, suggesting that QoL of children with even severe asthma could be improved when EIA is appropriately controlled.ConclusionsExistence of EIA among asthmatic children most strongly impairs their QoL. We should be more cautious about the management of EIA.     

International Study of Asthma and Allergies in Childhood (ISAAC): validation of the written questionnaire (eczema component) and prevalence of atopic eczema among Brazilian children.

Although Hanifin and Rajka's criteria have been used for the diagnosis of atopic eczema (AE), there is no instrument destined for epidemiological studies on AE that actually uses them. Written questionnaires (WQ) have generally been used, but when translated into another language they must be validated. The Intemational Study of Asthma and Allergies in Childhood (ISAAC) WQ was previously validated in a comprehensive study, but its validation in Brazil had not been done. Our objective was to validate the eczema component of the self-applicable ISAAC's WQ following its translation into Portuguese. The group of 10 pediatricians and 10 pediatric allergologists graded the questions from 0 to 2 and established the maximum score for each question. The WQ was answered by parents or guardians of children with atopic dermatitis (AE), aged 6-7 years (n = 23) and of non-AE control children of the same age (n = 46) as well as by AE (n = 24) and non-AE (n = 48) adolescents, aged 13-14 years. In order to evaluate the reproducibility of the ISAAC WQ, half of these individuals answered the same questionnaire after 2 to 4 weeks. The maximum possible global scores were 13 for the children aged 6-7 years and 11 for the adolescents, and the cutoff level for both groups was 3. In both age periods the WQ was reproducible (Kappa and McNemar tests) in a significant way (6-7 years, Kw = 0.79; 13-14 years, Kw = 0.73). The prevalence of AE, using the validated WQ, was then studied. The WQ was applied to the parents of 3,005 children aged 6-7 years and to 3008 children aged 13-14 years. Response rates were 72% and 94% for the 6-7-year-old children and the 13-14-year-old children, respectively. There was a slight predominance of male children in the studied population. In the group of the 6-7-year-old children, the cumulative prevalence of AE was 13.2% for boys and for girls; in the group of the 13-14-year-old children, it was 12.5% and 15.4%, respectively. AE severity was similar for both age groups. Using the criteria of global cutoff score, in the group of the 6-7-year-old children, the prevalence of AE was 12.6% for boys and 13.8 for girls; in the group of the 13-14-year-old children, it was 11.7% and 12.4%, respectively. There were no significant differences between them. In conclusion, the AE component of the ISAAC WQ proved to be reproducible, adequate, and able to discriminate between AE and control children. A significant concordance was observed between the criteria utilized in this study (ISAAC x global cutoff score).     

Urbanization and the Risk of Asthma Among Schoolchildren in the Palestinian Authority

The aim of the present survey was to compare the prevalence of symptoms suggestive of asthma in boys and girls aged 6-7 and 13-14 years in a rural and an urban area in the West Bank. For this purpose, the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was issued to 970 schoolchildren in the two regions. The response rate was 92.2%. The prevalences of ever wheezing in the urban and rural areas were 16.4% and 12.0%, respectively (p < 0.05); the 12-month prevalences of wheezing were 10.5% and 5.5%, respectively (p < 0.05); the prevalences of more severe wheeze were 4.5% and 1.7%, respectively (p < 0.05); and prevalences of diagnosed asthma were 4.2% and 2.8%, respectively (p = NS). When controlling for age by stratification, the significant association between prevalence rates and place of residence persisted in the 13-14-year age group. These results also show that the prevalence of asthma among Palestinian children is moderately high in comparison with that reported from developing countries, but lower than those reported from Western countries. This survey, the first epidemiological survey on asthma in the West Bank, demonstrates a marked difference between urban and rural areas. The findings emphasize the need for further study of the environmental determinants of the disease among Palestinian children.     

Asthma prevalence in children living in north Mexico City and a comparison with other Latin American cities and world regions.

Reports of previous studies done without following the international guidelines in different cities of Mexico showed a decrease in asthma prevalence. The aim of this study was to determine the prevalence and severity of asthma symptoms in children and teenagers living in north Mexico City and compare them with those of other Latin American cities and world regions. The cross-sectional survey followed the protocol of the International Study of Asthma and Allergies in Childhood IIIb phase survey. The study population included children 6-7 years old and teenagers 13-14 years old from randomly selected primary and secondary schools. There were 1629 boys and 1582 girls in the group of 6- to 7-year-old children and 2039 boys and 1860 girls in the 13- to 14-year-old group. "Wheezing or whistling in the chest at any time in the past" was present in 19.2% (95% confidence interval [CI], 17.9, 20.6) of the children and in 17.0% (95% CI, 15.8, 18.1) of the teenagers; "wheezing or whistling in the chest in the last 12 months" was reported in 6.8% (95% CI, 5.9, 7.6) of the children and 9.9% (95% CI, 9.0, 10.8) of the teenagers; "asthma ever" was claimed in 4.5% (95% CI, 3.8, 5.2) of the children and 8.0% (95% CI, 7.1, 8.8) of the teenagers. These prevalences were low compared with other ISAAC Latin American surveys and intermediate in comparison with worldwide regional prevalences reported by ISAAC surveys. The prevalence of asthma is low in Mexico City in comparison with other surveyed locations, but the number of patients with asthma makes it an important issue for Mexican public health programs.     

Identification of asthma risk factors in Mexico City in an International Study of Asthma and Allergy in Childhood survey.

The International Study of Asthma and Allergy in Childhood (ISAAC) has assessed the prevalence of asthma, as well as the factors related to the disease in different countries. The aim of this study was to identify asthma risks factors in Mexico City. Data were obtained from questionnaires of children participating in a phase 3b ISAAC survey. Two thousand ninety-eight boys and 2008 girls were recruited in the 6- to 7-year-old group and 3243 boy and 3333 girls were recruited in the 13- to 14-year-old group. Logistic regression was used to determine the asthma risks factors. In the logistic regression for cumulative and current asthma prevalence, the variables allergic rhinitis and atopic dermatitis were the most important risk factors with the highest odds ratios (OR > 1.5; p < 0.05). The use of antibiotics and paracetamol in the first 12 months of life were related to cumulative asthma in both genders in the 6- to 7-year-old group. Contact of pregnant mother with farm animals was positively related with cumulative asthma in boys in the 6- to 7-year-old group. The main factors associated with the cumulative and current prevalence of asthma in both age groups were atopic dermatitis and allergic rhinitis. Future interventions for the prevention and early diagnosis and treatment could be focused in the natural history of the atopic march.     

Urbanization and the risk of asthma among schoolchildren in the Palestinian Authority.

The aim of the present survey was to compare the prevalence of symptoms suggestive of asthma in boys and girls aged 6-7 and 13-14 years in a rural and an urban area in the West Bank. For this purpose, the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was issued to 970 schoolchildren in the two regions. The response rate was 92.2%. The prevalences of ever wheezing in the urban and rural areas were 16.4% and 12.0%, respectively (p < 0.05); the 12-month prevalences of wheezing were 10.5% and 5.5%, respectively (p < 0.05); the prevalences of more severe wheeze were 4.5% and 1.7%, respectively (p < 0.05); and prevalences of diagnosed asthma were 4.2% and 2.8%, respectively (p = NS). When controlling for age by stratification, the significant association between prevalence rates and place of residence persisted in the 13-14-year age group. These results also show that the prevalence of asthma among Palestinian children is moderately high in comparison with that reported from developing countries, but lower than those reported from Western countries. This survey, the first epidemiological survey on asthma in the West Bank, demonstrates a marked difference between urban and rural areas. The findings emphasize the need for further study of the environmental determinants of the disease among Palestinian children.     

Environmental Noise and Asthma in Children: Sex-Specific Differences

Objective. There is evidence that stress increases the risk of asthma. Chronic noise exposure is known to act as an unspecific stressor, but little is known about its effect on the risk of asthma in children. The aim of this study was to compare subjectively reported noise annoyance in 12-year-old asthmatic and non-asthmatic children with special regard to sex-specific differences. Subjects and methods. In a German multi-center birth cohort study we assessed the annoyance by different sources of environmental noise, doctor-diagnosed asthma, and potential confounders by questionnaire. The comparisons between asthmatic and non-asthmatic children were stratified by sex. Results. A total of 336 boys and 316 girls were included in the analysis. Prevalence of doctor-diagnosed asthma was 13% in boys and 5% in girls; 73% of the boys and 74% of the girls reported at least some degree of noise annoyance during the day and night time. In girls, asthma was associated with a significantly increased total noise annoyance at night (adjusted odds ratio aOR 1.5, 95%CI 1.1;2.1), for noise within the home/apartment (aOR 3.5, 95%CI 1.5;8.0), and in or around the house (aOR 3.3, 95%CI 1.7;6.3). No statistical significant effects were seen in boys. Conclusions. Noise annoyance, particularly at night or caused by domestic sources, is associated with increased asthma prevalence in girls but not boys. Further research is needed to identify underlying mechanisms of these sex-specific differences.     

Adolescent respiratory symptoms--girls are at risk: the Young-HUNT study, Norway

The objective was to study sex differences in adolescence regarding prevalence of asthma and current wheeze and to explore the association between respiratory symptoms and hereditary, lifestyle and socioeconomic factors. Young-HUNT included data comprehensive questionnaire on health, disease, lifestyle and social factors from 8817 teenagers 13-19 years conducted in 1995/97 (89% response rate). Questionnaire on respiratory symptoms was based on the International Study of Asthma and Allergy in Childhood (ISAAC). In age groups 13-16 and 17-19 years, current wheeze was reported by 29.0% and 33.5% among girls and 20.4% and 22.1% among boys, whilst the corresponding figures for asthma were 8.5% and 12.2% among girls and 7.1% and 7.0% among boys. Both wheeze and asthma were significantly more prevalent and increased with age in girls compared to boys. Heredity was associated with asthma, but the association was strongest between parents and children of the same sex. Environmental smoking was associated with asthma and wheeze in girls only. Girls reported more asthma and wheeze in association with overweight compared to boys. Girls reported more wheeze and asthma than boys and seemed more susceptible to risk factors such as environmental smoking and overweight than boys. Moreover, girls with mothers having asthma were more likely to be diagnosed as asthmatics themselves.     

Prevalence of asthma among Qatari schoolchildren: International Study of Asthma and Allergies in Childhood, Qatar

The aim of the present study is to determine the prevalence of asthma and allergic diseases among schoolchildren aged 6-14 years in the State of Qatar, based on a questionnaire designed by the International Study of Asthma and Allergy in Childhood (ISAAC). A cross-sectional study of 3,283 school children living in both urban and rural areas (average age, 9.03 +/- 1.99 years; 52.3% boys and 47.7% girls) was conducted between February 2003-February 2004. The population sample had a high prevalence of diagnosed asthma (19.8%), allergic rhinitis (30.5%), eczema (22.5%), and chest infection (11.9%). The frequency of asthma, allergic rhinitis, and eczema among parents reflected the same pattern as seen in their children. Overall, males had more asthma, allergic rhinitis, and chest infections than females. In general, the prevalence rate of asthma and allergic rhinitis decreased with age. The prevalence rate of asthma was significantly higher in mothers (11.8%) than in fathers (9.0%), but the frequency of allergic rhinitis symptoms was comparable (mothers, 18.5%; fathers, 17.5%). The prevalence rate of asthma (19.8%) in Qatari schoolchildren is very close to that in the neighboring Gulf country, Oman (20.7%), and higher than in some developing countries. Genetic factors related to the high rates of consanguinity may play an important role in the high prevalence rates noted in the Qatari population, but changes in lifestyle and environmental factors cannot be discounted as possible causes of the high prevalence noted in this study.     

Prevalence of Asthma and Other Childhood Allergies in Brazilian Schoolchildren

We determined the prevalence of asthma, rhinitis, and eczema among Brazilian children using the standardized protocol of the International Study on Asthma and Allergies in Childhood (ISAAC) to facilitate the comparison of our results with other studies using the ISAAC methodology. We conducted a cross-sectional study from June to October 1994 to determine the prevalence of asthma, rhinitis, and eczema in 5182 school children aged 7-8 years and 13-14 years residing in the Brazilian towns of Santa Maria and Itabira (iron-mining cities located in Minas Gerais). Parents completed questionnaires at their child's school in the presence of trained interviewers. The cumulative prevalence of doctor-diagnosed asthma was 4.6% for all ages with no significant difference between the age groups. In general, there was a higher prevalence of symptoms in the younger age group than the older. The prevalence of wheezing in the previous 12 months was 14.3% (7-8 years old) and 9.3% (13-14 years old) (p ≤ 0.01), of chronic cough in the previous 12 months was 25.6% (7-8 years old) and 22.1% (13-14 years old) (p ≤ 0.01), and of nighttime cough in the previous 12 months was 22.3% (7-8 years old) and 19.4% (13-14 years old) (p ≤ 0.05). Overall the prevalences of asthma and wheezing symptoms in the previous 12 months were higher for boys than girls (5.2% vs. 3.9% for asthma, p ≤ 0.01, and 13.2% vs. 10.6% for wheezing, p ≤ 0.01, respectively). These results suggest that asthma-related respiratory illnesses affect a substantial part of the childhood population in Itabira and Santa Maria, Minas Gerais. Some factors such as male gender and younger age may be associated with an increase risk for chronic respiratory symptoms. Prevalences of asthma and allergic diseases in these Brazilian cities on the basis of self-reporting of symptoms and of one's medical history may more accurately portray the true prevalence of asthma than the use of medical records.     

International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire: validation of the asthma component among Brazilian children.

Written questionnaires have been widely used in epidemiological studies of asthma. However, when translated to another language, they must be validated. The International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire had been previously validated by a comprehensive study, but this had not been done in Brazil. Our objective was to validate the asthma component of the ISAAC self-applicable written questionnaire following its translation to Portuguese. A group of 10 pediatricians and 10 pediatric allergists graded the questions from 0 to 2, and established a maximum score for each question. The questionnaire was answered by parents or guardians of asthmatic children, aged 6 to 7 years old (n = 26) and of nonasthmatic control children of the same age (n = 26); and by asthmatic (n = 33) and nonasthmatic (n = 33) adolescents, aged 13 to 14 years. Half of these individuals responded to the same questionnaire after 2 to 4 weeks. This second response allowed the evaluation of the reproducibility of the ISAAC questionnaire. The maximum global score possible was 14, and cut-off levels of 5 and 6 were found for the groups of 6 to 7 and 13 to 14 year olds, respectively. There was significant agreement between the adolescents' responses to the questionnaire and those from their parents or guardians (74.3%); however, significant discordance was observed for individual questions including "wheezing with exercise." In both age periods the questionnaire was significantly reproducible (Kappa test) (6 to 7 year olds Kw = 1; 13 to 14 year olds Kw = 0.89). In conclusion, the asthma component of the ISAAC written questionnaire was proven to be reproducible, adequate and able to differentiate between asthmatics and controls. Adolescents answered the questionnaire appropriately, however the results suggest that adolescents' parents or guardians underestimate asthma symptoms which interfere little with the adolescent's daily activities.     

Breastfeeding and Asthma Among Brazilian Children

We examined the association of breastfeeding and the presence of chronic respiratory symptoms among 5182 Brazilian schoolchildren 7-14 years of age who were participants in the International Study on Asthma and Allergies in Childhood (ISAAC). The prevalence of medically diagnosed asthma and current wheeze were respectively 4.6% (95% confidence interval [CI] 4.0%-5.2%) and 11.9% (95% CI 11.0%-12.8%). Ninety percent of the mothers in our study population had breastfed their child. After adjusting for potential confounding factors, we found that children who had not been breastfed were more likely to have a medical diagnosis of asthma (odds ration [OR] = 1.51, 95% CI 1.00-2.51), experience current wheeze (OR = 1.29, 95% CI 0.96-1.74), and wheeze after exercise (OR = 1.51, 95% CI 1.01-2.27) than children who had been breastfed for more than 6 months. This effect was only present among children with no family history of asthma (OR = 1.54, 95% CI 0.90-2.42 for medical diagnosis of asthma; OR = 1.27, 95% CI 0.93-1.75 for current wheezing; and OR = 1.74, 95% CI 1.12-2.6 for wheeze after exercise). We conclude that the low prevalence of asthma and wheeze observed in our population may be partly related to the high level of breastfeeding.     

Asthma prevalence in European, Maori, and Pacific children in New Zealand: ISAAC study

The International Study of Asthma and Allergies in Childhood (ISAAC) demonstrated that the highest prevalence of asthma in the world is in English-speaking countries, including New Zealand. In this paper, we compare asthma symptom prevalence in the three major ethnic groups (Maori, Pacific, and European) in the six participating centers in New Zealand. Hospital admission rates for asthma are higher among Maori and Pacific children compared to European children. The working hypothesis was that there were important differences in prevalence of asthma symptoms or diagnosis between ethnic groups which might explain these observed differences in asthma morbidity. In each center in 1992-1993, we sampled approximately 3000 children at each of the age brackets 6-7 years and 13-14 years. There were 37592 participants. Maori children had higher rates of diagnosed asthma and reported asthma symptoms than Pacific children in both age groups (diagnosed asthma in 6-7-year-olds: Maori, 31.7%; Pacific, 21.2%; 95% confidence interval on difference (CID), 7.2, 13.8; P < 0.001; 13-14-year-olds: Maori, 24.7%; Pacific, 19.2%; CID 2.5, 8.5; P < 0.001; recent wheeze in 6-7-year-olds: Maori, 27.6%; Pacific, 22.0%; CID, 2.6, 8.6; P < 0.001; 13-14-year-olds: Maori, 30.8%; Pacific, 21.1%; CID, 4.8, 14.5; P < 0.001;). European children had rates intermediate between those of Maori and Pacific children (6-7-year-olds) or similar to those of Maori children (13-14-year-olds), but had the lowest prevalence of night waking with wheeze in both age groups (e.g., 6-7-year-olds: European, 2.6%; Maori, 5.8%; Pacific, 5.7%; European-Maori CID: -4.2, -2.2, P < 0.001; European-Pacific CID: -4.7, -1.7, P < 0.001; Maori-Pacific CID: -1.7, 1.8, P = 1.0). The pattern of differences closely resembled that in a 1985 Auckland study, despite a 1.5-1.7-fold overall increase in prevalence. In conclusion, there are important differences in asthma prevalence among Maori, Pacific, and European children. These differences are small compared to worldwide variation, but their pattern is stable over time. The higher rate of severe asthma symptoms that Maori and Pacific children report may be one reason for the increased asthma morbidity in these groups. Further studies are needed to determine the reasons for these apparent differences in asthma severity.     

Prevalence,Demographics, and Health Outcomes of Comorbid Asthma and Overweight in Urban Children

Background. Asthma and overweight are epidemic in urban children but the relationship between these conditions is not fully understood. This study presents demographic and risk profiles of comorbidity for overweight asthmatic children, characterizes morbidity by comparing health outcomes among overweight asthmatics and healthy weight asthmatics, and examines socioeconomic factors associated with comorbidity. Objective. To construct a demographic profile of overweight asthmatic children in an urban setting and identify factors that contribute to prevalence. Method. Cross-sectional study of 5250 children in New York City public elementary schools using a parent-report questionnaire on body mass index, socioeconomic status, asthma, and asthma-related outcomes. Results. Prevalence of overweight (body mass index ≥ 85th percentile for age and gender) was 50.9%. The prevalence of overweight and ever being diagnosed with asthma was 10.9%. The prevalence of overweight with current asthma was 6.2%. Overweight current asthmatics had more night symptoms, missed school days, and asthma medication use than healthy weight asthmatics. Almost 50% of overweight current asthmatic children reported emergency department visits for asthma compared with 30% of healthy weight asthmatics. Comorbidity was most prevalent among males, Latinos, and children in low-income households, with the highest prevalence among Puerto Ricans. In multivariate analysis stratified by gender, the most significant factors associated with comorbidity among girls were low income and minority race/ethnicity, while among boys significant factors were parental education and parental history of asthma. Interestingly, there were few underweight children (7.8%) but they had high prevalence of asthma (13.8%). Conclusions. The comorbidity of overweight and asthma has a large impact on urban populations, causing greater disease burden than asthma alone. Overweight asthmatics show more uncontrolled asthma, evidenced by emergency department visits, quick-relief medication use, and days with asthma symptoms. The relationship between socioeconomic factors and the asthma–obesity comorbidity may vary by gender and requires further study to identify successful interventions to reduce disease in children.     

Frequency of Allergic Rhinitis in School-age Children (7-18 Years) in Tehran

Allergic Rhinitis (AR) is one of the most common allergic disorders of childhood. In order to determine the frequency of AR among school-age children, a cross-sectional study was performed. One thousand, nine hundred and thirty-two children (931 boys and 1001 girls), aged 7-18 years, from 30 systematic randomly selected schools of Tehran, the capital of Iran, were investigated in this study. Screening was made on the basis of the questionnaire according to International Study of Asthma and Allergies in Childhood protocol. Diagnosis was confirmed by history and physical examination. Four hundred and fifty-five (240 boys and 215 girls) out of 1932 screened children had AR (23.5%). Seasonal AR and perennial forms were detected in 329 and 126 cases, respectively. The symptoms of seasonal AR were noted at spring (68.7%), summer (15.8%), and fall and winter (15.5%). The total prevalence of asthma was 3.5% according to questionnaire, which was lower than the prevalence (7.2%) in the AR subjects. The prevalence of cutaneous allergy also was 35.8% in children with AR. The positive history of atopy (AR, asthma, or cutaneous allergy) in the first degree relatives was detected in 47.9% in AR cases. Moreover, the history of contact with animals was positive in 35.4% of cases with AR. AR is common among school-age children in Tehran. Coincidence of AR with asthma or cutaneous allergy is significant. Family history of allergy and history of contact with animals and cockroaches are important risk factors in the incidence of AR.     

Prevalence of asthma symptoms in Latin America: the International Study of Asthma and Allergies in Childhood (ISAAC)

The prevalence of respiratory symptoms indicative of asthma in children from Latin America has been largely ignored. As part of the International Study of Asthma and Allergies in Childhood (ISAAC), 17 centers in 9 different Latin American countries participated in the study, and data from 52,549 written questionnaires (WQ) in children aged 13-14 years and from 36,264 WQ in 6-7 year olds are described here. In children aged 13-14 years, the prevalence of asthma ever ranged from 5.5-28%, and the prevalence of wheezing in the last 12 months from 6.6-27%. In children aged 6-7 years, the prevalence of asthma ever ranged from 4.1-26.9%, and the prevalence of wheezing in the last 12 months ranged from 8.6-32.1%. The lower prevalence in centers with higher levels of atmospheric pollution suggests that chronic inhalation of polluted air in children does not contribute to asthma. Furthermore, the high figures for asthma in a region with a high level of gastrointestinal parasite infestation, and a high burden of acute respiratory infections occurring early in life, suggest that these factors, considered as protective in other regions, do not have the same effect in this region. The present study indicates that the prevalence of asthma and related symptoms in Latin America is as high and variable as described in industrialized or developed regions of the world.     

Prevalence of atopic eczema and related symptoms in Brazilian schoolchildren: results from the International Study of Asthma and Allergies in Childhood (ISAAC) phase 3.

BACKGROUND: International comparisons of the prevalence of atopic eczema and related symptoms are scarce. The standardized protocol of the International Study of Asthma and Allergies in Childhood (ISAAC) facilitates investigation of prevalence all over the world. OBJECTIVE: To apply the ISAAC written questionnaire to evaluate the prevalence of atopic eczema and related symptoms among 6-7 year-old children and 13-14 year-old adolescents living in 20 Brazilian cities. METHODS: The ISAAC written questionnaire was filled in by 23,422 children aged 6-7 years and 58,144 adolescents aged 13-14 years living in 2 population centers in the north, 8 in the northeast, 1 in the midwest, 5 in the southeast, and 5 in the south. RESULTS: The prevalence of flexural eczema (itchy rash ever in characteristic places in the last 12 months) ranged from 5.3% to 13.0% for children and was lower among the adolescents (range, 3.4%-7.9%). Among children, the highest rates were observed in population centers in the northeast, mainly along the coast. Among adolescents the highest rates were observed in the north and northeast, mainly in Natal, Aracaju, and Vitória da Conquista. The northeastern countryside had higher prevalence rates of severe eczema (kept awake at night by this itchy rash in the last 12 months) in comparison to northeastern coastal centers. There was a significant correlation between the prevalence of flexural eczema and severe eczema for both age groups, separately (6-7 year-olds, prho= 0.756, P<.004; 13-14 year-olds, rho=0.874, P<.0001) or grouped (6-7 plus 13-14 years-olds, rho=0.696, P<.0001). CONCLUSION: The prevalence of eczema and related symptoms is variable in Brazil, where the highest prevalence is found in the north and northeast; on the other hand, a higher prevalence of severe eczema was observed in Brazilian centers in the south.