Adrian M Brooke

Are all wheezing disorders in very young (preschool) children increasing in prevalence

BACKGROUND Distinct wheezing disorders co-exist in young (preschool) children, some of which (early transient wheeze and viral wheeze) are thought to be unrelated to atopy. Investigation of changes in prevalence of wheezing disorders in preschool children could provide important clues about underlying mechanisms responsible for increasing prevalence of asthma in schoolchildren. METHODS Repeated population surveys of the prevalence of respiratory symptoms were done by parent-completed postal questionnaires in random samples of 1650 (1990) and 2600 (1998) caucasian children aged 1-5 years living in the county of Leicestershire, UK. FINDINGS The response rates were 86% (1422 of 1650) in 1990 and 84% (2127 of 2522) in 1998. Between 1990 and 1998, there was a significant increase in the prevalance of reported wheeze ever (16% to 29%, p<0.0001), current wheeze (12% to 26%, p<0.0001), diagnosis of asthma (11% to 19%, p<0.0001), treatment for wheeze (15% to 26%, p<0.0001), and admission for wheeze or other chest trouble (6% to 10%, p<0.0001). The increase occurred both in children with viral wheeze (9% to 19%) and in those with the classic asthma pattern of wheezing with multiple triggers (6% to 10%). There was also an increase in transient early wheezers (3% to 5%), persistent wheezers (5% to 13%), and late-onset wheezers (6% to 8%), and in all severity groups. The increase could not be accounted for by putative household risk factors because these declined between the 2 years. INTERPRETATION The fact that all preschool wheezing disorders increased (including viral wheeze) makes it probable that factors unrelated to atopy are implicated in the changing epidemiology of wheeze in childhood.

Distinguishing phenotypes of childhood wheeze and cough using latent class analysis

Airway disease in childhood comprises a heterogeneous group of disorders. Attempts to distinguish different phenotypes have generally considered few disease dimensions. The present study examines phenotypes of childhood wheeze and chronic cough, by fitting a statistical model to data representing multiple disease dimensions. From a population-based, longitudinal cohort study of 1,650 preschool children, 319 with parent-reported wheeze or chronic cough were included. Phenotypes were identified by latent class analysis using data on symptoms, skin-prick tests, lung function and airway responsiveness from two preschool surveys. These phenotypes were then compared with respect to outcome at school age. The model distinguished three phenotypes of wheeze and two phenotypes of chronic cough. Subsequent wheeze, chronic cough and inhaler use at school age differed clearly between the five phenotypes. The wheeze phenotypes shared features with previously described entities and partly reconciled discrepancies between existing sets of phenotype labels. This novel, multidimensional approach has the potential to identify clinically relevant phenotypes, not only in paediatric disorders but also in adult obstructive airway diseases, where phenotype definition is an equally important issue.

Recurrent cough: Natural history and significance in infancy and early childhood

We investigated the outcome for a sample of children in whom recurrent cough was reported in the preschool years to determine (1) whether they shared the characteristics attributed to cough variant asthma, and (2) the proportion who developed classical wheezy asthma at follow‐up during the early school years. A cohort of children identified as having recurrent cough in the preschool period was reassessed during the early school years. Previously identified asymptomatic preschool children who remained symptom‐free provided a comparison group with respect to current respiratory symptoms, lung function, bronchial reactivity to inhaled methacholine, atopic status, peak flow variability, and recorded night cough.

Wheeze and asthma prevalence and related health-service use in white and south Asian pre-schoolchildren in the United Kingdom.

Background Epidemiological data for south Asian children in the United Kingdom are contradictory, showing a lower prevalence of wheeze, but a higher rate of medical consultations and admissions for asthma compared with white children. These studies have not distinguished different asthma phenotypes or controlled for varying environmental exposures.

Wheeze in preschool children and its relation with doctor diagnosed asthma.

OBJECTIVE--To describe the characteristics of wheeze and its relation with doctor diagnosed asthma in children aged 5 years and under. DESIGN--Questionnaire survey of population based random sample of children registered on Leicestershire Health Authoritys child health index for immunisation; questionnaire completed by parents. SUBJECTS--1650 white children born in 1985 to 1989 who were surveyed in 1990. MAIN OUTCOME MEASURES--Age distribution, severity, precipitants, seasonal characteristics, and diurnal variation of wheeze, family history of asthma/atopy, and their association(s) with doctor diagnosed asthma. RESULTS--There were 1422 replies (86.2%). Two hundred and twenty two (15.6%) were reported to have wheezed and of these 121 (8.6%) had formally been diagnosed as having asthma. More than 80% of the former had recurrences of wheeze and 40% (72) had three or more episodes in the preceding 12 months. Age, number of episodes per year, the severity of shortness of breath with attacks, and precipitants other than colds were the major factors determining the probability that a wheezy child will be diagnosed as having asthma. The data also suggest that despite the strong association of symptom based criteria with the label asthma, asthma was not diagnosed by these same severity criteria in one quarter of cases. CONCLUSIONS--Clinical and physiological follow up studies of children identified as asthmatic by the above criteria during the preschool years should validate or refute the predictive value of these measures of wheeze severity.

Night cough in a population-based sample of children: characteristics, relation to symptoms and associations with measures of asthma severity

Nocturnal cough in asthma is a common but poorly understood phenomenon. The aims of this study were to determine the relationship between recorded night cough, reported night cough and current wheeze in a population-based sample of children previously identified as wheezy, and to examine the relationship of nocturnal cough to current symptoms, markers of asthma severity and environmental exposure. Children were reassessed in the early school years by measuring current symptoms, ventilatory function, bronchial reactivity, peak flow variability, respiratory symptom diaries and home monitoring of overnight cough, transcutaneous arterial oxygen saturation, room temperature and humidity. Night studies were performed on 59 asymptomatic children and 41 children with current wheeze. Cough occurred more frequently in current wheezers compared to asymptomatic children (16 out of 41 (39%) vs 11 out of 59 (19%)), and more cough episodes were recorded (median 3.5 vs 2.0). Night cough was not associated with bronchial reactivity, peak flow variability, degree of morning dip, mean overnight arterial oxygen saturation, ventilatory function, maternal smoking or treatment of asthma. However, it was associated with lower overnight air temperature. Although night cough is more common in current wheezers, there is poor agreement between recorded and reported night cough. Objective tests of asthma severity are of little use in predicting its presence in this age group. The sleeping environment deserves further study.

Health for all children, 4th edition

Edited by David Hall, David Elliman. . Oxford: Published by Oxford University Press, 2006, £21.95 (paperback), 422. This 400-page volume has proved quite a difficult book to review. The ‘Health for all children’ books are a cornerstone of child health practice when considering broad populations of children. The publication of each edition is keenly awaited and goes on to influence both the organisation and prosecution of child health services throughout the UK and beyond. This revision of the fourth edition is due to the publication of several important documents concerning the health and welfare of children in the UK, namely the National service framework for children and Every child matters . Emerging data from SureStart programmes are also starting to shape the future direction of …

Vaccinations as risk factors for wheezing disorders

if we included only children with onset of wheeze after age 1 year (eg, after full primary immunisation) or only children with positive family history of atopy. We cannot definitely rule out a small positive or negative effect of childhood immunisations on the prevalence of atopy in individual children, but changed immunisation schemes do not explain the rise in reported preschool wheeze between 1990 and 1998 in Leicestershire. Our results add to the evidence from other large surveys that do not confirm an increased risk of wheeze in immunised children. In a large crosssectional population survey of nearly 10 000 children and in a randomised clinical trial in Sweden, there was no effect of pertussis vaccination on the prevalence of atopic disease. At present, scientific evidence does certainly not support the withholding of childhood immunisations from children at risk of atopic disease.