Epidemiological study of wheeze,doctor diagnosed asthma,and cough in preschool children in Leicestershire.

OBJECTIVE--To determine the cumulative prevalences of wheeze and doctor diagnosed asthma and the point prevalences of recurrent cough and wheeze in children aged 5 years and under. DESIGN--Questionnaire survey of population based random sample of children registered on regional authority''s child health index for immunisation; questionnaire completed by parents. SETTING--Leicestershire. SUBJECTS--1650 white children born in 1985-9 who were surveyed in 1990. MAIN OUTCOME MEASURES--Cumulative prevalences of wheeze and doctor diagnosed asthma and point prevalences of recurrent cough and wheeze by age and sex. RESULTS--There were 1422 replies (86.2%; 726 for boys, 696 for girls). Overall, 11.0% (95% confidence interval 9.4% to 12.6%) of children had formally been diagnosed as having asthma, the cumulative prevalence in boys (12.7%) being somewhat higher than in girls (9.2%) (age adjusted odds ratio 1.47, p = 0.03). As expected, the cumulative prevalence of asthma increased significantly with age (7.5% (13/173) in children under 1 year, 15.9% (61/383) in children of 4 years and over; p < 0.001). The cumulative prevalence of wheeze overall was 15.6% (13.7% to 17.5%), being higher in boys (17.6%) than in girls (13.5%) (odds ratio 1.38, p = 0.03). The overall prevalence of recurrent cough without colds was 21.8% (19.6% to 23.9%), with a non-significant excess in boys (23.1% v 20.4%). The overall prevalence of wheezing attacks during the previous 12 months was 13.0% (11.3% to 14.8%) with a non-significant excess in boys (14.5% v 11.5%). CONCLUSIONS--These findings are baseline results and emphasise the importance of studying the age group of interest rather than relying on the recall of parents of school age children.     

Pet ownership and associated respiratory diseases

Background Studies have shown that pets are very important sensitizing agents in patients with asthma. Respiratory disorders and allergic diseases are common in the State of Qatar. Objective The aim of the present study was to determine whether exposure to pets and domestic animals plays a significant role in the development of asthma and allergic rhinitis among Qatari school children aged 6–14 years. Design A cross-sectional prospective study. Setting Public schools for boys and girls in urban and semi-urban areas. Subjects A total of 3,500 Qatari school boys and girls aged 6–14 years were approached. After exclusion of those who did not give consent for the study and incomplete questionnaires, 3,283 (98.3%) participants were included in the data analysis. Methods A multistage sampling technique was used and different schools from urban and semi-urban areas were selected. A standard questionnaire was distributed to parents of randomly selected school children aged 6–14 years between February 2003 and February 2004. Results The overall prevalence of asthma was 19.8% and the mean age of the children was 9.0 ± 2.0 years. The male and female percentages were 52.3% and 47.7% respectively. Nine hundred and ninety-six families out of 3,283 (30.3%) owned pets. It was found that among children with no family history of asthma, the relative risk (RR) of asthma with pets at home was 1.19 and the 95% confidence interval (CI) was 1.0–1.4 (P = 0.025). The RR of having allergic rhinitis was 1.60 (95% CI = 1.4–1.8; P < 0.001) and risk of having eczema was also significantly higher in participants with pets at home (RR = 1.28; 95% CI = 1.1–1.5; P < 0.001). Conclusion In the present study, the prevalence of asthma, allergic rhinitis, and eczema was significantly more common in families with domestic animals than in those without.     

Factors associated with difference in prevalence of asthma in children from three cities in China: multicentre epidemiological survey

Objective To determine the factors associated with difference in prevalence of asthma in children in different regions of China.Design Multicentre epidemiological survey.Setting Three cities in China.Participants 10 902 schoolchildren aged 10 years.Main outcome measures Asthma and atopic symptoms, atopic sensitisation, and early and current exposure to environmental factors.Results Children from Hong Kong had a significantly higher prevalence of wheeze in the past year than those from Guangzhou and Beijing (odds ratio 1.64, 95% confidence interval 1.35 to 1.99). Factors during the first year of life and currently that were significantly associated with wheeze were cooking with gas (odds ratio 2.04, 1.34 to 3.13), foam pillows (2.58, 1.66 to 3.99), and damp housing (1.89, 1.26 to 2.83). Factors protecting against wheeze were cotton quilts and the consumption of fruit and raw vegetables.Conclusion Environmental factors and diet may explain the differences in prevalence of asthma between children living in different regions of China.     

Underdiagnosis and undertreatment of asthma in childhood.

A total of 179 Tyneside children who had suffered at least one episode of wheeze since school entry were seen at the age of 7. All but 14 had visited a doctor for chest symptoms, but a diagnosis of asthma had been offered to the parents of only 21 children, including three of the 56 children experiencing four to 12 wheezy episodes a year and 11 of the 31 children experiencing more than 12 episodes a year. Bronchodilator treatment was rarely offered in the absence of such a diagnosis, and two thirds of the children had never received a bronchodilator. Of the children experiencing four or more episodes a year, only a third had received bronchodilator drugs regularly, though half had lost more than 50 days from school because of wheeze. School absenteeism fell 10-fold in the 31 children finally offered continuous prophylactic treatment. Although many doctors had feared that use of the word "asthma" would cause anxiety, parents were uniformly relieved when given an explanation of their child''s recurrent wheeze. This study uncovered a disturbing amount of ill health in children that was easily rectified. Probably this same problem exists in other areas.     

Does Pet Ownership in Infancy Lead to Asthma or Allergy at School Age? Pooled Analysis of Individual Participant Data from 11 European Birth Cohorts

Objective

To examine the associations between pet keeping in early childhood and asthma and allergies in children aged 6–10 years.

Design

Pooled analysis of individual participant data of 11 prospective European birth cohorts that recruited a total of over 22,000 children in the 1990s.

Exposure definition

Ownership of only cats, dogs, birds, rodents, or cats/dogs combined during the first 2 years of life.

Outcome definition

Current asthma (primary outcome), allergic asthma, allergic rhinitis and allergic sensitization during 6–10 years of age.

Data synthesis

Three-step approach: (i) Common definition of outcome and exposure variables across cohorts; (ii) calculation of adjusted effect estimates for each cohort; (iii) pooling of effect estimates by using random effects meta-analysis models.

Results

We found no association between furry and feathered pet keeping early in life and asthma in school age. For example, the odds ratio for asthma comparing cat ownership with “no pets” (10 studies, 11489 participants) was 1.00 (95% confidence interval 0.78 to 1.28) (I² = 9%; p = 0.36). The odds ratio for asthma comparing dog ownership with “no pets” (9 studies, 11433 participants) was 0.77 (0.58 to 1.03) (I² = 0%, p = 0.89). Owning both cat(s) and dog(s) compared to “no pets” resulted in an odds ratio of 1.04 (0.59 to 1.84) (I² = 33%, p = 0.18). Similarly, for allergic asthma and for allergic rhinitis we did not find associations regarding any type of pet ownership early in life. However, we found some evidence for an association between ownership of furry pets during the first 2 years of life and reduced likelihood of becoming sensitized to aero-allergens.

Conclusions

Pet ownership in early life did not appear to either increase or reduce the risk of asthma or allergic rhinitis symptoms in children aged 6–10. Advice from health care practitioners to avoid or to specifically acquire pets for primary prevention of asthma or allergic rhinitis in children should not be given.     

The natural history of childhood asthma to adult life.

A randomly selected group of 331 children who had started to wheeze in childhood and a control group of 77 children were prospectively studied clinically and physiologically from 7 to 21 years of age. Most subjects improved during adolescence and about 55% of those whose wheezing had started before 7 years and stopped before adolescence remained wheeze free. Forty-five per cent of subjects who had apparently ceased to wheeze at 14 years had minor recurrences of wheezing between 14 and 21 years of age. Fewer than 20% of those with persistent symptoms in childhood had become totally wheeze free during adolescence, although there was amelioration in symptoms. Girls did less well during adolescence than boys, so that there was no longer an increased preponderance of boys with increasing severity of asthma. Normal growth was achieved in all grades despite the persistence of symptoms in many cases. At 21 years of age features of airways obstruction were often found during an interval phase, especially in those who had more persistent symptoms.     

Prevalence and spectrum of asthma in childhood.

All the 7 year old schoolchildren in North Tyneside were screened for wheeze with a questionnaire followed by selective clinical assessment: 9.3% of the children had had episodic wheeze within the past year and all those followed up subsequently responded to one or more of the drugs used for asthma. A further 1.8% had had similar symptoms since starting school, though they had not wheezed in the past year. Frequently of symptoms in the 11% of children with features of asthma varied widely and correlated with bronchial reactivity on histamine challenge, but it was not possible to separate children with frequent wheeze from asymptomatic controls by their response to histamine. It was concluded that all these wheezy children had symptoms of a common basic disorder and that they should all be treated as asthmatic.     

Respiratory symptoms and atopy in Aberdeen schoolchildren: evidence from two surveys 25 years apart.

OBJECTIVE--To estimate changes in the prevalence of respiratory symptoms and the reported diagnoses of asthma, eczema, and hay fever in primary school children in Aberdeen between 1964 and 1989. DESIGN--Determination of incidence prevalence and prevalence from survey data. SETTING--Aberdeen, Scotland. PARTICIPANTS--2743 primary school children (aged 8-13) from 1964 and 4003 [corrected] from 1989. MAIN OUTCOME MEASURES--Survey data on whether, according to the parent or guardian, the child wheezed or was troubled with shortness of breath; the number of episodes of breathlessness in the past year; and whether asthma, eczema, or hay fever had ever been diagnosed. RESULTS--Questionnaires were completed by the parents of 2510 children in 1964 and 3403 children in 1989. The prevalence of wheeze rose from 10.4% in 1964 to 19.8% in 1989, and the prevalence of episodes of shortness of breath increased from 5.4% to 10.0%. In both surveys wheeze and shortness of breath were more prevalent in boys than in girls. The reported diagnosis of asthma rose from 4.1% to 10.2%, hay fever from 3.2% to 11.9%, and eczema from 5.3% to 12%. The proportion of boys suffering from eczema rose from 47.7% to 60.0%. Hay fever showed a similar increase, from 49.4% to 60.1%, in boys over the 25 year period. Though the parents of a higher proportion of children with wheeze were aware of the diagnosis of asthma in 1989, because of the increased prevalence of wheeze the absolute number of parents of wheezy children who were not aware of a diagnosis of asthma increased from 7.4% to 9.6% of the population studied. CONCLUSION--The higher diagnosis rate for asthma is due not simply to changes in diagnostic fashion but reflects an increase over the past 25 years in the prevalence of respiratory symptoms, which in turn may reflect a more general change in the prevalence of atopy, the increase in which was particularly noticeable in boys. This increase explains some of the increase in hospital admission rates for children with asthma.     

Prevalence of asthma in Melbourne schoolchildren: changes over 26 years.

OBJECTIVES--To determine the prevalence of asthma in the past 12 months in Melbourne schoolchildren aged 7, 12, and 15 years and to compare the prevalence of a history of asthma with that of 26 years ago. DESIGN--A questionnaire on respiratory symptoms was distributed to children for completion by parents and return to the school. Subjects were selected by a stratified cluster design. SETTING--Government and non-government schools in the greater Melbourne area, Australia. SUBJECTS--10,981 children. Parents completed questionnaires for 3324 children aged 7, 2899 aged 12, and 2968 aged 15. The overall response rate was 90%. MAIN OUTCOME MEASURES--History of wheeze or asthma in the past 12 months and in lifetime. RESULTS--The prevalences of wheeze in the past 12 months were 23.1%, 21.7%, and 18.6% for 7, 12, and 15 year olds respectively. A history of wheeze was more common in boys than in girls at age 7 (443/1711 v 324/1614) and 12 (418/1767 v 322/1718) but not at age 15. Overall, 78% (1548) of those reporting wheeze also reported a history of asthma and 83% (1611) had used a bronchodilator. The prevalence of a history of asthma among 7 year olds was 46% compared with 19.1% in the 1964 survey, an increase of 141%. CONCLUSIONS--The current prevalence of asthma in Melbourne schoolchildren is high and has risen substantially over the past 26 years.     

Association between childhood atopic disease and parental atopic disease in a population with high consanguinity

The aim of the study was to investigate the association between asthma, allergic rhinitis, and eczema in Qatari schoolchildren with allergic conditions in their parents. A cross-sectional study was conducted among 3500 Qatari schoolchildren aged 6-14 years in period: February, 2003-February, 2004. A questionnaire was used to collect the clinical history of asthma and allergic rhinitis in their parents and siblings. It was found that 21.6% of asthmatic children had mothers with asthma and 18.2% fathers with asthma. This contrasted with 6.8% of non-asthmatic children who had fathers with asthma and 9.4% mothers with asthma. As for allergic rhinitis, 26.5% of asthmatic children had mothers with allergic rhinitis and 25.3% fathers with allergic rhinitis. The frequency of either parent of the asthmatic children having allergic rhinitis was 41.8% and for both parents was 10.0%. The frequency of siblings having asthma was 36.6%, allergic rhinitis 16.4%, and eczema 29.1%. The present study revealed a strong association between respiratory allergies and eczema in parents, and their asthmatic children.     

The Urban Environment and Childhood Asthma (URECA) birth cohort study: design, methods, and study population

Background

The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA) study, which was established to investigate the immunologic causes of asthma among inner-city children.

Methods and Results

URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses) that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated ex vivo are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years.

Conclusion

The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.     

Long term prognosis in preschool children with wheeze: longitudinal postal questionnaire study 1993-2004

Objectives To follow a population of preschool children with and without parent reported wheeze over a period of 6-11 years to determine prognosis and its important predictive factors.Design Longitudinal series of five postal surveys based on the international study of asthma and allergies in childhood questionnaire carried out between 1993 and 2004.Setting Two general practice populations, south Manchester.Participants 628 children aged less than 5 years at recruitment and those with at least six years’ follow-up data.Main outcome measures Parent completed questionnaire data for respiratory symptoms and associated features.Results Of 628 children included in the study, 201 (32%) had parent reported wheeze at the first observation (baseline), of whom 27% also reported the symptom on the second occasion (persistent asthma). The only important baseline predictors of persistent asthma were exercise induced wheeze (odds ratio 3.94, 95% confidence interval 1.72 to 9.00) and a history of atopic disorders (4.44, 1.94 to 10.13). The presence of both predictors indicated a likelihood of 53.2% of developing asthma; if only one feature was present this decreased to 17.2%, whereas if neither was present the likelihood was 10.9%. Family history of asthma was not predictive of persistent asthma among children with preschool wheeze.Conclusion Using two simple predictive factors (baseline parent reported exercise induced wheeze and a history of atopic disorders), it is possible to estimate the likelihood of future asthma in children presenting with preschool wheeze. The absence of baseline exercise induced wheeze and a history of atopic disorders reduces the likelihood of subsequent asthma by a factor of five.     

Wheeze in preschool age is associated with pulmonary bacterial infection and resolves after antibiotic therapy

Background

Neonates with airways colonized by Haemophilus influenzae, Streptococcus pneumoniae or Moraxella catarrhalis are at increased risk for recurrent wheeze which may resemble asthma early in life. It is not clear whether chronic colonization by these pathogens is causative for severe persistent wheeze in some preschool children and whether these children might benefit from antibiotic treatment. We assessed the relevance of bacterial colonization and chronic airway infection in preschool children with severe persistent wheezing and evaluated the outcome of long-time antibiotic treatment on the clinical course in such children.

Methodology/Principal Findings

Preschool children (n = 42) with severe persistent wheeze but no symptoms of acute pulmonary infection were investigated by bronchoscopy and bronchoalveolar lavage (BAL). Differential cell counts and microbiological and virological analyses were performed on BAL samples. Patients diagnosed with bacterial infection were treated with antibiotics for 2–16 weeks (n = 29). A modified ISAAC questionnaire was used for follow-up assessment of children at least 6 months after bronchoscopy. Of the 42 children with severe wheezing, 34 (81%) showed a neutrophilic inflammation and 20 (59%) of this subgroup had elevated bacterial counts (≥10⁴ colony forming units per milliliter) suggesting infection. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were the most frequently isolated species. After treatment with appropriate antibiotics 92% of patients showed a marked improvement of symptoms upon follow-up examination.

Conclusions/Significance

Chronic bacterial infections are relevant in a subgroup of preschool children with persistent wheezing and such children benefit significantly from antibiotic therapy.     

Trends in prevalence and severity of childhood asthma.

OBJECTIVE--To test the null hypothesis that there has been no change in the prevalence or severity of childhood asthma over recent years. DESIGN--Repeated population prevalence survey with questionnaires completed by parents followed by home interviews with parents. SETTING--London borough of Croydon, 1978 and 1991. SUBJECTS--All children in one year of state and private primary schools aged 7 1/2 to 8 1/2 years at screening survey. MAIN OUTCOME MEASURES--Trends in symptoms, acute severe attacks, and chronic disability. RESULTS--For 1978 and 1991 respectively, the response rates were 4147/4763 and 3070/3786, and home interviews were obtained from 273/288 and 319/395 parents of currently wheezy children. Between 1978 and 1991 there were significant relative increases in prevalence ratios in the 12 month prevalence of attacks of wheezing or asthma (1.16; 95% confidence interval 1.02 to 1.31), the one month prevalence of wheezing episodes (1.78; 1.15 to 2.74), and the one month prevalence of night waking (1.81; 1.01 to 3.23) but not in frequent (> or = 5) attacks over the past year (1.05; 0.79 to 1.40). There were substantial and significant decreases in the 12 month prevalence of absence from school of more than 10 days due to wheezing (0.52; 0.30 to 0.90), any days in bed (0.67; 0.44 to 1.01), and restriction of activities at home (0.51; 0.31 to 0.83) and an equivalent but not significant fall in speech limiting attacks (0.51; 0.24 to 1.11). CONCLUSION--The small increase in the prevalence of wheezy children and relatively greater increase in persistent wheezing suggests a change in the environmental determinants of asthma. In contrast and paradoxically the frequency of wheezing attacks remains unchanged and there are indications that severe attacks and chronic disability have fallen by about half; this may be due to an improvement in treatment received by wheezy children.     

Prevalence of asthma and allergic disorders among children in united Germany: a descriptive comparison.

OBJECTIVES--To compare the prevalence of asthma and allergic disorders among children in Munich, western Germany, and Leipzig, eastern Germany, where environmental exposure, particularly air concentrations of sulphur dioxide and particulate matter, and living conditions have differed over the past 45 years. DESIGN--Prevalence surveys among school-children aged 9-11 years in Leipzig and Munich. Self completion of written questionnaire by the children''s parents and lung function measurements. SUBJECTS--1051 children in Leipzig and 5030 in Munich. SETTING--Primary schools. MAIN OUTCOME MEASURES--Reported lifetime prevalence of asthma and allergic disorders, and bronchial hyperresponsiveness assessed by cold air inhalation challenge. RESULTS--The lifetime prevalence of asthma diagnosed by a doctor was 7.3% (72) in Leipzig and 9.3% (435) in Munich; prevalence of wheezing were 20% (191) and 17% (786) respectively. The prevalence of diagnosed bronchitis was higher in Leipzig than Munich (30.9% (303) v 15.9% (739); p < 0.01). A significant drop in forced expiratory volume (> 9%) after cold air challenge was measured in 6.4% (57) of children in Leipzig and in 7.7% (345) of those in Munich. Hay fever (2.4% (24) v 8.6% (410); p < 0.01) and typical symptoms of rhinitis (16.6% (171) v 19.7% (961); p < 0.05) were reported less often in Leipzig than in Munich. CONCLUSIONS--No significant differences were seen in the lifetime prevalence of asthma, wheezing, and bronchial hyperresponsiveness between children in Leipzig and Munich. The lifetime prevalence of bronchitis was higher in Leipzig than in Munich. The lower prevalence rates of allergic disorders in Leipzig could point toward aetiological factors that are associated with Western lifestyle and living conditions.     

Poverty,dirt, infections and non-atopic wheezing in children from a Brazilian urban center

Background

The causation of asthma is poorly understood. Risk factors for atopic and non-atopic asthma may be different. This study aimed to analyze the associations between markers of poverty, dirt and infections and wheezing in atopic and non-atopic children.

Methods

1445 children were recruited from a population-based cohort in Salvador, Brazil. Wheezing was assessed using the ISAAC questionnaire and atopy defined as allergen-specific IgE ≥0.70 kU/L. Relevant social factors, environmental exposures and serological markers for childhood infections were investigated as risk factors using multivariate multinomial logistic regression.

Results

Common risk factors for wheezing in atopic and non-atopic children, respectively, were parental asthma and respiratory infection in early childhood. No other factor was associated with wheezing in atopic children. Factors associated with wheezing in non-atopics were low maternal educational level (OR 1.49, 95% CI 0.98-2.38), low frequency of room cleaning (OR 2.49, 95% CI 1.27-4.90), presence of rodents in the house (OR 1.48, 95% CI 1.06-2.09), and day care attendance (OR 1.52, 95% CI 1.01-2.29).

Conclusions

Non-atopic wheezing was associated with risk factors indicative of poverty, dirt and infections. Further research is required to more precisely define the mediating exposures and the mechanisms by which they may cause non-atopic wheeze.     

A Disease Model for Wheezing Disorders in Preschool Children Based on Clinicians' Perceptions

Background

Wheezing disorders in childhood vary widely in clinical presentation and disease course. During the last years, several ways to classify wheezing children into different disease phenotypes have been proposed and are increasingly used for clinical guidance, but validation of these hypothetical entities is difficult.

Methodology/Principal Findings

The aim of this study was to develop a testable disease model which reflects the full spectrum of wheezing illness in preschool children. We performed a qualitative study among a panel of 7 experienced clinicians from 4 European countries working in primary, secondary and tertiary paediatric care. In a series of questionnaire surveys and structured discussions, we found a general consensus that preschool wheezing disorders consist of several phenotypes, with a great heterogeneity of specific disease concepts between clinicians. Initially, 24 disease entities were described among the 7 physicians. In structured discussions, these could be narrowed down to three entities which were linked to proposed mechanisms: a) allergic wheeze, b) non-allergic wheeze due to structural airway narrowing and c) non-allergic wheeze due to increased immune response to viral infections. This disease model will serve to create an artificial dataset that allows the validation of data-driven multidimensional methods, such as cluster analysis, which have been proposed for identification of wheezing phenotypes in children.

Conclusions/Significance

While there appears to be wide agreement among clinicians that wheezing disorders consist of several diseases, there is less agreement regarding their number and nature. A great diversity of disease concepts exist but a unified phenotype classification reflecting underlying disease mechanisms is lacking. We propose a disease model which may help guide future research so that proposed mechanisms are measured at the right time and their role in disease heterogeneity can be studied.     

Can morbidity associated with untreated asthma in primary school children be reduced?: a controlled intervention study.

OBJECTIVE--To determine whether an intervention programme based on existing school and community resources can reduce school absence and improve participation in games lessons and sport in children with unrecognised or undertreated asthma. DESIGN--Parallel group controlled intervention study. SETTING--102 primary schools in Nottingham: 49 were randomised to receive the intervention and 53 to be control schools. SUBJECTS--All children aged 5 to 10 years with parent reported absence from school because of wheezing in the previous year and taking no treatment or beta agonists only. INTERVENTIONS--Children with asthma were referred to their general practitioner for assessment of symptoms and treatment. Teachers were given education on asthma by the school nurse in 44 of the 49 intervention schools. MAIN OUTCOME MEASURES--Changes in school absence and missed games and swimming lessons because of wheezing, and schools'' policy towards management of asthma in school. RESULTS--Of 17,432 children screened, 451 met the entry criteria--228 in intervention schools and 223 in control schools. 152 (67%) children in intervention schools visited their general practitioner, of whom 39 (26%) were given a new diagnosis of asthma and 58 (38%) had treatment for asthma increased or changed. Over the next academic year mean (SE) parent reported school absence due to wheezing fell significantly, but to a similar extent, in both intervention and control schools (0.82 (0.11) and 1.09 (0.21) weeks respectively). There was little change in school recorded absence or participation in games lessons and swimming lessons in either group. At the end of the study intervention schools were more likely to have improved aspects of management of asthma in school. CONCLUSION--The intervention resulted in a majority of children being assessed by their general practitioner and improved teachers'' understanding and management of asthma, but it did not result in any appreciable reduction in morbidity.     

Community study of role of viral infections in exacerbations of asthma in 9-11 year old children.

OBJECTIVE--To study the association between upper and lower respiratory viral infections and acute exacerbations of asthma in schoolchildren in the community. DESIGN--Community based 13 month longitudinal study using diary card respiratory symptom and peak expiratory flow monitoring to allow early sampling for viruses. SUBJECTS--108 Children aged 9-11 years who had reported wheeze or cough, or both, in a questionnaire. SETTING--Southampton and surrounding community. MAIN OUTCOME MEASURES--Upper and lower respiratory viral infections detected by polymerase chain reaction or conventional methods, reported exacerbations of asthma, computer identified episodes of respiratory tract symptoms or peak flow reductions. RESULTS--Viruses were detected in 80% of reported episodes of reduced peak expiratory flow, 80% of reported episodes of wheeze, and in 85% of reported episodes of upper respiratory symptoms, cough, wheeze, and a fall in peak expiratory flow. The median duration of reported falls in peak expiratory flow was 14 days, and the median maximum fall in peak expiratory flow was 81 l/min. The most commonly identified virus type was rhinovirus. CONCLUSIONS--This study supports the hypothesis that upper respiratory viral infections are associated with 80-85% of asthma exacerbations in school age children.     

Prenatal and Postnatal Exposure to Phthalate Esters and Asthma: A 9-Year Follow-Up Study of a Taiwanese Birth Cohort

Previous studies have shown that phthalate exposure in childhood is associated with the development of respiratory problems. However, few studies have assessed the relative impact of prenatal and postnatal exposure to phthalates on the development of asthma later in childhood. Therefore, we assessed the impact of prenatal and postnatal phthalate exposure on the development of asthma and wheezing using a Taiwanese birth cohort. A total of 430 pregnant women were recruited, and 171 (39.8%) of them had their children followed when they were aged 2, 5, and 8 years. The International Study of Asthma and Allergies in Childhood questionnaire was used to assess asthma and wheezing symptoms and serum total immunoglobulin E levels were measured at 8 years of age. Urine samples were obtained from 136 women during their third trimester of pregnancy, 99 children at 2 years of age, and 110 children at 5 years. Four common phthalate monoester metabolites in maternal and children’s urine were measured using liquid chromatography-electrospray ionization-tandem mass spectrometry. Maternal urinary mono-benzyl phthalate [MBzP] concentrations were associated with an increased occurrence of wheezing in boys at 8 years of age (odds ratio [OR] = 4.95 (95% CI 1.08–22.63)), for upper quintile compared to the others) after controlling for parental allergies and family members'' smoking status. Urinary mono-2-ethylhexyl phthalate [MEHP] levels over the quintile at 2-year-old were associated with increased asthma occurrence (adjusted OR = 6.14 (1.17–32.13)) in boys. Similarly, the sum of di-2-ethyl-hexyl phthalate [DEHP] metabolites at 5 years was associated with asthma in boys (adjusted OR = 4.36 (1.01–18.86)). Urinary MEHP in maternal and 5-year-old children urine were significantly associated with increased IgE in allergic children at 8 years. Prenatal and postnatal exposure to phthalate was associated with the occurrence of asthma in children, particularly for boys.