Prevalence, natural history, and relationship of wheezy bronchitis and asthma in children. An epidemiological study

Time to Say Goodbye to Bronchiolitis, Viral Wheeze, Reactive Airways Disease, Wheeze Bronchitis and All That

The diagnosis and management of infants and children with a significant viral lower respiratory tract illness remains the subject of much debate and little progress. Over the decades various terms for such illnesses have been in and fallen out of fashion or have evolved to mean different things to different clinicians. Terms such as "bronchiolitis," "reactive airways disease," "viral wheeze," and many more are used to describe the same condition and the same term is frequently used to describe illnesses caused by completely different dominant pathologies. This lack of clarity is due, in large part, to a failure to understand the basic underlying inflammatory and associated processes and, in part, due to the lack of a simple test to identify a condition such as asthma. Moreover, there is a lack of insight into the fact that the same pathology can produce different clinical signs at different ages. The consequence is that terminology and fashions in treatment have tended to go around in circles. As was noted almost 60 years ago, amongst pre-school children with a viral LRTI and airways obstruction there are those with a "viral bronchitis" and those with asthma. In the former group, a neutrophil dominated inflammation response is responsible for the airways' obstruction whilst amongst asthmatics much of the obstruction is attributable to bronchoconstriction. The airways obstruction in the former group is predominantly caused by airways secretions and to some extent mucosal oedema (a "snotty lung"). These patients benefit from good supportive care including supplemental oxygen if required (though those with a pre-existing bacterial bronchitis will also benefit from antibiotics). For those with a viral exacerbation of asthma, characterized by bronchoconstriction combined with impaired b-agonist responsiveness, standard management of an exacerbation of asthma (including the use of steroids to re-establish bronchodilator responsiveness) represents optimal treatment. The difficulty is identifying which group a particular patient falls into. A proposed simplified approach to the nomenclature used to categorize virus associated LRTIs is presented based on an understanding of the underlying pathological processes and how these contribute to the physical signs.

A review on the pathophysiology of asthma remission

Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission. Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.

Fluoride Exposure Induces Inhibition of Sodium-and Potassium-Activated Adenosine Triphosphatase (Na+, K+-ATPase) Enzyme Activity: Molecular Mechanisms and Implications for Public Health

In this study, several lines of evidence are provided to show that Na + , K + -ATPase activity exerts vital roles in normal brain development and function and that loss of enzyme activity is implicated in neurodevelopmental, neuropsychiatric and neurodegenerative disorders, as well as increased risk of cancer, metabolic, pulmonary and cardiovascular disease. Evidence is presented to show that fluoride (F) inhibits Na + , K + -ATPase activity by altering biological pathways through modifying the expression of genes and the activity of glycolytic enzymes, metalloenzymes, hormones, proteins, neuropeptides and cytokines, as well as biological interface interactions that rely on the bioavailability of chemical elements magnesium and manganese to modulate ATP and Na + , K + -ATPase enzyme activity. Taken together, the findings of this study provide unprecedented insights into the molecular mechanisms and biological pathways by which F inhibits Na + , K + -ATPase activity and contributes to the etiology and pathophysiology of diseases associated with impairment of this essential enzyme. Moreover, the findings of this study further suggest that there are windows of susceptibility over the life course where chronic F exposure in pregnancy and early infancy may impair Na + , K + -ATPase activity with both short- and long-term implications for disease and inequalities in health. These findings would warrant considerable attention and potential intervention, not to mention additional research on the potential effects of F intake in contributing to chronic disease.

Cor Triatriatum: Case Report of Emergency Department Diagnosis

Cor triatriatum is a rare, congenital heart defect. When diagnosis does not occur in infancy, primary symptoms in an older patient may mimic reactive airway disease. We report a case of cor triatriatum in an older child, previously diagnosed with asthma, presenting to an emergency department with a chief complaint of wheezing. Initial treatment with bronchodilators and corticosteroids was unsuccessful, prompting thorough evaluation. Subsequent imaging diagnosed cor triatriatum sinister. When presentations consistent with common conditions, such as asthma, do not respond appropriately to classic intervention, emergency physicians must be prepared to consider alternative and rare diagnosis.

Improving the global diagnosis and management of asthma in children

Asthma is the most common chronic condition in children worldwide. It affects daytime activities, sleep and school attendance and causes anxiety to parents, families and other carers. The quality of asthma diagnosis and management globally still needs substantial improvement. From infancy to the teenage years, there are age-specific challenges, including both underdiagnosis and overdiagnosis with stigma-related barriers to treatment in some cultures and in adolescents. Guidelines are increasingly evidence based, but their impact on improving outcomes has been negligible in many parts of the world, often due to lack of implementation. New thinking is needed to enable substantial improvements in outcomes. The disease varies globally and plans will need to differ for individual countries or places where region-specific barriers prevent optimal care. A wide selection of educational activities is needed, including community-targeted initiatives, to engage with families. The Paediatric Asthma Project Plan has been initiated to strengthen diagnosis and management of asthma. This encompasses a vision for the next 10–15 years, building on the knowledge and experience from previous educational projects. It will take into account the educational needs of patients, carers and healthcare professionals as well as the accessibility and affordability of medication, particularly in low and middle-income countries where the prevalence of asthma is rising more rapidly. This overview presents a first step for those involved in the diagnosis and management of childhood asthma to strengthen care for children globally.

Impact of childhood wheezing on lung function in adulthood: A meta-analysis

BACKGROUND

A growing body of evidence shows that childhood wheezing may lead to recurrent or persistent symptoms in adulthood, such that persistent wheezing associated with lung function deficits often have their roots in the first few years of life.

OBJECTIVES

We summarized information from several prospective cohort studies following children with or without wheezing into adulthood, to estimate the effect of childhood wheezing on adulthood lung function.

METHODS

Medical literatures were searched in the Medline, PubMed, ScienceDirect, Web of Science and Embase databases up to October 31, 2016. The adulthood lung function was selected as primary outcome, and chronic obstructive pulmonary disease (COPD) prevalence was selected as secondary outcome. The meta-analysis was performed with the Stata Version 14.0. A random-effects model was applied to estimate standardized mean difference (SMD) of lung function, and relative risk (RR) of COPD.

RESULTS

Six articles enrolling 1141 and 1005 children with and without wheezing, respectively. Meta-analysis showed that childhood wheezing decreased adulthood lung function as compared with no-wheezing subjects (SMD = -0.365, 95% confidence interval (CI): -0.569~-0.161, P = 0.000). Subgroup analyses indicated that childhood atopic wheezing reduced adulthood FEV1/FVC and FEV1%pred when compared with no-wheezing subjects. In addition, childhood atopic wheezing was significantly associated with COPD prevalence (RR = 5.307, 95% CI:1.033~27.271, P = 0.046).

CONCLUSIONS

Our meta-analysis suggests that childhood wheezing may induce ongoing declined lung function that extends into adult life, as well as an increased risk of COPD prevalence when accompanied with atopy.

In Utero Exposure to Aspirin and Risk of Asthma in Childhood

BACKGROUND

Aspirin is widely used in general population and low-dose aspirin is commonly prescribed to prevent recurrent pregnancy loss associated with antiphospholipid syndrome and preeclampsia, often used throughout pregnancy. But aspirin is associated with asthma pathogenesis. We aim to examine whether in utero exposure to aspirin at different fetal stages is associated with asthma in childhood.

METHODS

We used data from the Collaborative Perinatal Project. Maternal exposure to aspirin before and during pregnancy was recorded at each prenatal visit. Children were followed up to 7 years of age. A total of 19,928 singleton children without maternal history of asthma were included. We used multilevel multiple logistic regression models to control for potential confounders.

RESULTS

In utero exposure to aspirin was associated with an increased risk of childhood asthma (adjusted odds ratio [aORs] = 1.3, 95% confidence interval [CI] = 1.1, 1.6). aORs for exposure in first, second, and third trimesters were 1.1 (95% CI = 0.87, 1.3), 1.2 (95% CI = 1.0, 1.4), and 1.4 (95% CI = 1.1, 1.6), respectively. Furthermore, aORs of asthma were 1.3 (95% CI = 1.0, 1.7) and 1.3 (95% CI = 1.0, 1.7) for aspirin use for 2 to 7 days or more than 7 days in third trimester, respectively.

CONCLUSION

In utero exposure to therapeutic dose of aspirin even just briefly in late pregnancy is associated with childhood asthma by 7 years of age. More research is needed to carefully examine the association between low-dose aspirin with extended exposure period and long-term child outcomes.

Atopy in people aged 40 years and over: Relation to airflow limitation

BACKGROUND

Previous studies have reached conflicting conclusions about the role of atopy as a risk factor for COPD. In part, this is attributable to variation in the definitions of airflow limitation and the treatment of people with asthma.

OBJECTIVE

To establish whether there is any independent association between atopy and post-bronchodilator airflow limitation in the general population aged 40 years and over.

METHODS

A cross-sectional survey was conducted in a general population sample of 2415 people aged 40 years and over in Australia. A history of ever being diagnosed with asthma was elicited by questionnaire. Atopy was defined as any skin prick test weal to common aeroallergens ≥4 mm. Airflow limitation was defined as post-bronchodilator spirometric (FEV₁ /FVC) ratio <lower limit of normal. Analyses were adjusted for potential confounding due to age, sex, smoking, race and socio-economic status.

RESULTS

The prevalence of atopy, ever diagnosed asthma and post-bronchodilator airflow obstruction was 44.8%, 19.3% and 7.5%, respectively. In the population as a whole, atopy was associated with lower FEV₁ (adjusted difference -0.068L, 95% confidence interval (CI) -0.104 to -0.032), FVC (adj. difference -0.043L, 95% CI -0.086 to -0.0009) and post-bronchodilator FEV₁/FVC ratio (adj. difference -0.011, 95% CI -0.017 to -0.0055). The effect of atopy on lung function was no longer apparent when participants who reported ever diagnosed asthma were excluded (FEV₁ -0.011L, [95% CI -0.05 to 0.028L], FVC -0.012L [95% CI -0.060 to 0.036] and FEV₁/FVC ratio -0.0012 [95% CI -0.0072 to 0.0047L]).

CONCLUSION AND CLINICAL RELEVANCE

The apparent association between atopy and post-bronchodilator airflow limitation in the general population appears to be explained by the association between atopy and having ever diagnosed asthma and the effect of asthma on lung function.

Childhood asthma is a risk factor for the development of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

This review will catalog the many recent longitudinal studies that have investigated the relationship between asthma and lung function, or the persistence and trajectories of lung function deficits.

RECENT FINDINGS

Recent work has reported on 50-year follow-ups of some prominent population cohorts. A history of asthma confers a 10-30-fold risk of chronic obstructive pulmonary disease. Individuals reaching a reduced maximum growth of forced expiratory volume in 1 s in early adulthood are at risk for early or more severe chronic obstructive pulmonary disease (COPD).

SUMMARY

Taken together, there is a wealth of overlapping cohort studies of lung function, asthma and COPD. These show that asthma is associated with reduced lung function, which may start in infancy or prenatally, persists through childhood and adulthood and predisposes for early or more severe COPD.

Infantile wheeze: rethinking dogma

Wheeze is a common symptom in young children and is usually associated with viral illnesses. It is a major source of morbidity and is responsible for a high consumption of healthcare and economic resources worldwide. A few children have a condition resembling classical asthma. Rarer specific conditions may have a wheezy component and should be considered in the differential diagnosis. Over the last half century, there have been many circular discussions about the best way of managing preschool wheeze. In general, intermittent wheezing should be treated with intermittent bronchodilator therapy, and a controller therapy should be prescribed for a young child with recurrent wheezing only if positively indicated, and only then if carefully monitored for efficacy. Good multidisciplinary support, attention to environmental exposition and education are essential in managing this common condition. This article analyses the pathophysiological basis of wheezing in infancy and critically discusses the evolution of the scientific progress over time in this unique field of respiratory medicine.

Strengths, Pitfalls, and Lessons from Longitudinal Childhood Asthma Cohorts of Children Followed Up into Adult Life

Asthma is a common problem worldwide and longitudinal studies of children followed up into adult life enable the assessment of clinical outcomes, examine the pattern of lung function outcomes, and importantly provide insight into aetiology and prognosis for patients with asthma. The aim of this review is to examine the major childhood asthma cohort studies which have continued into adult life, describing the strengths and weaknesses and the lessons that can be learnt regarding pathophysiology and potential future directions for research.

Childhood asthma and chronic obstructive pulmonary disease: outcomes until the age of 50

PURPOSE OF REVIEW

There has been recent interest in understanding the origins of chronic obstructive pulmonary disease. Epidemiological studies suggest that chronic obstructive pulmonary disease clearly has other causes apart from tobacco smoke.

RECENT FINDINGS

Cross-sectional studies of adult cohorts with chronic obstructive pulmonary disease highlight that childhood asthma is a risk factor. A recent longitudinal childhood cohort study of children from childhood to the age of 50 years describes that children with severe asthma are at increased risk of chronic obstructive pulmonary disease and that the deficit in lung function can be tracked back to early years.

SUMMARY

Children with severe asthma are at increased risk of developing chronic obstructive pulmonary disease.

Trends in eczema, rhinitis, and rye grass sensitization in a longitudinal asthma cohort

BACKGROUND

Atopic conditions are prevalent in the Western world, with limited long-term data on atopic trends in patients with asthma.

OBJECTIVE

To describe the trends in eczema, rhinitis, and allergic sensitization in a longitudinal childhood asthma cohort.

METHODS

Four hundred eighty-four patients were recruited at 7 years of age and followed regularly to 50 years of age. Subjects completed an interviewer-administered questionnaire to define current eczema and rhinitis. Skin prick testing to rye grass also was performed.

RESULTS

The participation rate over the past 4 decades has been maintained at 72% to 91%. There was a decrease in the prevalence of eczema in the past 12 months in groups with viral-associated wheeze (21% to 8%, P = .002), asthma (47% to 18%, P < .001), and severe asthma (69% to 28%, P < .001) from 14 to 21 years of age. Conversely, there was an increase in the prevalence of rhinitis in the previous 12 months in groups without asthma (1% to 6%, P = .04; 1% to 20%, P = .008), with viral-associated wheeze (16% to 28%, P = .006; 16% to 49%, P < .001), and with asthma (45% to 56%, P = .2; 45% to 73%, P = .014) from recruitment to 10 and 14 years of age, respectively. There were 2 peaks in prevalence in the sensitization to rye grass in this cohort from 7 to 10 years of age and from 14 to 21 years of age in all groups.

CONCLUSION

The adolescence phase appears to be an important period in the body's response to allergens whereby eczema decreases in prevalence, whereas rhinitis and rye grass sensitization increase in prevalence.

Outcomes of childhood asthma to the age of 50 years

BACKGROUND

In 1964, The Melbourne Asthma Study was established to describe the spectrum and natural history of childhood asthma.

OBJECTIVE

To describe the clinical and lung function outcome of childhood asthma to the age of 50 years.

METHOD

Subjects were invited to complete an interviewer-administered questionnaire, skin prick testing, and measurement of lung function from the age of 7 years to the age of 50 years at 7-year intervals.

RESULTS

Of 458 survivors (from the original 484 subjects at recruitment), 346 subjects (76%) participated, of whom, 197 completed lung function measurement. Asthma remission at the age of 50 years was 64% in those with wheezy bronchitis, 47% for those with persistent asthma, and 15% for those with severe asthma in childhood. Multivariable analysis identified severe asthma in childhood (odds ratio [OR] 11.9 [95% CI, 3.4-41.8]), female sex (OR 2.0 [95% CI, 1.1-3.6]), and childhood hay fever (OR 2.0 [95% CI, 1.0-4.0]) as risk factors for "current asthma" at age 50 years. There was no evidence of a difference in the rate of decline in FEV1 (mL/y, 95% CI) between the severe asthma group (15 mL/y [95% CI, 9-22 mL/y]) and all the other recruitment groups: control (16 mL/y [95% CI, 12-20 mL/y]), mild wheezy bronchitis (14 mL/y [95% CI, 8-19 mL/y]), wheezy bronchitis (16 mL/y [95% CI, 11-20 mL/y]), and persistent asthma (19 mL/y [95% CI, 13-24 mL/y]).

CONCLUSION

The clinical and lung function outcome in adult life is strongly determined by asthma severity in childhood. The reduced lung function seen in adults is established in childhood and does not appear to decline more rapidly in adult years despite continuing symptoms.

Neonatal bilirubin levels and childhood asthma in the US Collaborative Perinatal Project, 1959-1965

Evidence shows that asthma originates in early life. Studies have found that phototherapy and/or neonatal jaundice may be associated with asthma. We investigated the association between neonatal bilirubin levels and childhood asthma without phototherapy intervention in the Collaborative Perinatal Project, a multicenter prospective cohort study conducted in the United States from 1959 to 1965. A total of 54,795 livebirths were included, and 40,063 children were followed up until 7 years of age or older. Total serum bilirubin (TSB) levels were examined at 48 hours postpartum in newborns with birthweights of 2,250 g or more. Information on asthma and other diseases through age 7 years was summarized and confirmed by a group of pediatricians and child neurologists. Among 28,807 term infants, the overall prevalence of asthma was 5.26%. Risks of asthma increased with both maximum TSB levels and TSB levels at 48 hours postpartum (P for trend < 0.01). Neonatal maximum TSB levels greater than 15 mg/dL were associated with a 61% increase in the risk of childhood asthma (odds ratio = 1.61, 95% confidence interval: 1.04, 2.08) after adjustment for confounders. In this prospective cohort study of infants born at a time when phototherapy was unavailable, neonatal hyperbilirubinemia was associated with an increased risk of childhood asthma.

Opening interrupter technique in pre-school children with chronic respiratory diseases: a perspective case-control study in the diagnosis of airway hyperesponsiveness

BACKGROUND

Optimal treatment for pediatric respiratory diseases is strictly related to follow-up evaluations of lung function. The aim of our study was to show the efficacy of the Opening Interrupter Technique in diagnosing the presence of airway obstruction in pre-school children.

MATERIALS AND METHODS

Our study was a prospective case-control study, evaluating 82 patients affected by asthma and/or cystic fibrosis (CF) and 50 healthy pre-school children, as control group. All patients were 3- to 5-years old and they were followed by our Pediatric Department, University of Catania, Italy, from February 2011 to June 2012. Measurements of respiratory resistance (o-Rint) by the opening interrupter technique were made with the MasterScreen PFT device, Jaeger GmbH, Würzburg, Germany, during quiet breathing. The presence of airway obstruction was detected as a value of o-Rint higher than two standard deviations (SD) compared with the theoretical data.

RESULTS

We found higher values of o-Rint in asthmatic patients than in the control group, with a high statistical difference (p < 0.0001). The same results were found when we compared patients with CF and the control group (p < 0.0001). Nevertheless, we did not find any significant statistical difference between respiratory resistances measured in asthmatic and patients with CF (p > 0.05). There was a significant inverse correlation between o-Rint and height only in asthmatic and patients with CF, but not in healthy controls (p < 0.05).

CONCLUSIONS

In our study, the opening interrupter technique was efficient in detecting the presence of obstruction in chronic patients affected by asthma and CF.

Long-term outcomes of early-onset wheeze and asthma

Evidence from longitudinal cohort studies demonstrates that wheezing that begins in early life and continues into the school years generally persists into adulthood. This persistent wheezing is associated with lung function deficits and airways hyperresponsiveness that appear to be established in the first few years of life. Allergic sensitization early in life, early-life infection with rhinovirus, or colonization with any of a number of bacteria have been associated with increased risk of persistent wheeze. Early life, whether in utero or in the first few years of life, presents a window of vulnerability during which airway injury results in persistent airways dysfunction. Available data further suggest that a second such window of vulnerability might be present in the preadolescent and adolescent years. Lung function growth patterns established by age 6 years generally continue into early adulthood to middle adulthood, typically leaving groups of subjects with wheezing that persists into or relapses during adulthood with a mean FEV(1) of about 10% of predicted value less than their peers who do not wheeze. Subgroups of patients with persistent asthma, however, can have progressive decreases in lung function and enter adulthood with even lower lung function. The concern exists that these deficits in lung function apparent in early adulthood might put subjects at risk for the later development of chronic obstructive pulmonary disease.

Fetal origins of asthma

There is convincing evidence that asthma has its origins in early life. We review the epidemiological and biological evidence for fetal exposures that may have a causal role in asthma development. However, those factors that provoke asthma exacerbations are not necessarily the same as those associated with disease induction. Epidemiological studies have identified many potential exposures linked to asthma but these do not confirm causality and have not been replicated by experiment. Asthma is a heterogeneous disease and there are developmental influences on at least two pathways, airway structure and airway inflammation. The fetus is not immunologically naive and intrauterine exposures can act directly to invoke immunological sensitisation leading postnatally to airway inflammation. Other potential mechanisms include indirect effects on airway and lung growth through fetal nutrition and epigenetic modifications of DNA expression by environmental exposures. Identifying the causal factors will provide the targets for interventions to prevent disease.

Phenotypes of childhood asthma: are they real?

It has been suggested that there are several distinct phenotypes of childhood asthma or childhood wheezing. Here, we review the research relating to these phenotypes, with a focus on the methods used to define and validate them. Childhood wheezing disorders manifest themselves in a range of observable (phenotypic) features such as lung function, bronchial responsiveness, atopy and a highly variable time course (prognosis). The underlying causes are not sufficiently understood to define disease entities based on aetiology. Nevertheless, there is a need for a classification that would (i) facilitate research into aetiology and pathophysiology, (ii) allow targeted treatment and preventive measures and (iii) improve the prediction of long-term outcome. Classical attempts to define phenotypes have been one-dimensional, relying on few or single features such as triggers (exclusive viral wheeze vs. multiple trigger wheeze) or time course (early transient wheeze, persistent and late onset wheeze). These definitions are simple but essentially subjective. Recently, a multi-dimensional approach has been adopted. This approach is based on a wide range of features and relies on multivariate methods such as cluster or latent class analysis. Phenotypes identified in this manner are more complex but arguably more objective. Although phenotypes have an undisputed standing in current research on childhood asthma and wheezing, there is confusion about the meaning of the term 'phenotype' causing much circular debate. If phenotypes are meant to represent 'real' underlying disease entities rather than superficial features, there is a need for validation and harmonization of definitions. The multi-dimensional approach allows validation by replication across different populations and may contribute to a more reliable classification of childhood wheezing disorders and to improved precision of research relying on phenotype recognition, particularly in genetics. Ultimately, the underlying pathophysiology and aetiology will need to be understood to properly characterize the diseases causing recurrent wheeze in children.

Is there a link between wheezing in early childhood and adverse birth outcomes? A systematic review

We aimed to provide a summary of the existing published knowledge on the association between adverse birth outcomes and the development of wheezing during the first two years of life. We carried out a systematic review of epidemiological studies within the MEDLINE database. Epidemiological studies on human subjects, published in English, were included in the review. A comprehensive literature search yielded 72 studies for further consideration. Following the application of the eligibility criteria we identified nine studies. A positive association and an excess risk of wheezing during the first two years of life were revealed for adverse birth outcomes.

Childhood respiratory illness and lung function at ages 14 and 50 years: childhood respiratory illness and lung function

BACKGROUND

Although childhood respiratory tract infections and low birth weight have both been associated with reduced adult lung function, little is known about the timing of these associations during life. We used data from the Newcastle Thousand Families Study to examine how these and other factors influenced FEV(1) at age 14 years and between 14 and 49 to 51 years.

METHODS

Detailed information was collected prospectively during childhood. At age 14 years, 252 members of the cohort were recruited into a case-control study of respiratory health, which included measurement of FEV(1). One hundred twenty-two of these were measured again at age 49 to 51 years. Linear regression models were used to examine cross-sectional and longitudinal influences on FEV(1).

RESULTS

Lower height (P < .001), lower BMI (P < .001), being breast fed for less than 4 weeks (P = .028), childhood history of severe respiratory illness (P = .014), childhood history of asthma (P = .004), childhood history of TB (P = .023), and birth into a lower social class (P = .049) were all significant independent predictors of lower FEV(1) at 14 years of age. Correspondingly, being a women (P < .001), and having a higher FEV(1) at age 14 years (P < .001), a lower standardized birth weight (P = .025), a greater lifetime number of cigarettes smoked (P = .007), and a childhood history of severe respiratory illness (P = .047) were all independently associated with a greater decline (or a smaller increase) in FEV(1) between age 14 and 49 to 51 years.

CONCLUSIONS

This study suggests that the change in FEV(1) between youth and middle age depends on several factors acting throughout life, including FEV(1) in adolescence, sex, cigarette smoking, birth weight, and childhood respiratory health.

What have we learned from prospective cohort studies of asthma in children?

Prospective cohort studies have provided a useful tool for the study of the natural history of asthma and lung function and for the development of concepts of asthma phenotypes during childhood. However, although observational epidemiology has indicated a large number of credible associations between environmental variables and asthma onset in childhood, it can be argued that it has yet to fulfill the promise of identifying modifiable, causal risk factors that are amenable to intervention for the primary or secondary prevention of disease. The development of efficient, high-throughput genotyping that can be applied to large, longitudinal cohorts with detailed data on exposures and phenotypic outcomes, opens the way for studies of genetic effects and gene-environment interactions that may come closer to identifying causal pathways between exposure and disease. Therefore, there continues to be an important role for large-scale, observational studies with careful attention to definition and evaluation of outcomes and plausible risk factors.

Pediatric asthma and related allergic and nonallergic diseases: patient-oriented evidence-based essentials that matter

Asthma is the most common medical diagnosis among hospitalized children. In the USA, asthma has accounted for approximately 15% of nonsurgical admissions to hospital in the pediatric age group. Asthma is also one of the leading causes for emergency care requirements, one of the leading causes for missed school, and a cause for considerable morbidity, disability and occasional mortality at all ages. Despite these discouraging statistics, convincing data indicate that this failure of asthma management is not the result of inadequate therapeutic potential, but instead represents ineffective delivery of medical care. Management of asthma and its major co-morbidities, allergic and nonallergic rhinitis, and atopic dermatitis requires a knowledge of the alternative therapies, natural history, and educational techniques for providing patients and families with the ability to manage these troublesome chronic disorders.

Ciclesonide versus other inhaled steroids for chronic asthma in children and adults

BACKGROUND

Inhaled corticosteroids (ICS) are an integral part of asthma management, and act as an anti-inflammatory agent in the airways of the lung. These agents confer both significant benefit in terms of symptom management and improvement in lung function, but may also cause harm in terms of local and systemic side-effects. Ciclesonide is a novel steroid that is metabolised to its active component in the lung, making it a potentially useful for reducing local side effects.

OBJECTIVES

To assess the efficacy and adverse effects of ciclesonide relative to those of other inhaled corticosteroids in the management of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group register of trials with pre-defined terms. Additional searches of PubMed and Clinicalstudyresults.org were undertaken. The literature searches for this review are current up to June 2007.

SELECTION CRITERIA

Randomised parallel or crossover studies were eligible for the review. We included studies comparing ciclesonide with other steroids both at nominally equivalent dose or lower doses of ciclesonide.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Twenty one trials involving 7243 participants were included. Equal daily doses of ciclesonide and beclomethasone (BDP) or budesonide (BUD) gave similar results for peak expiratory flow rates (PEF), although forced vital capacity (FVC) was higher with ciclesonide. Data on forced expired volume in one second (FEV1) were inconsistent. Withdrawal data and symptoms were similar between treatments. Compared with the same dose of fluticasone (FP), data on lung function parameters (FEV1, FVC and PEF) did not differ significantly. Paediatric quality of life score favoured ciclesonide. Candidiasis was less frequent with ciclesonide, although other side-effect outcomes did not give significant differences in favour of either treatment. When lower doses of ciclesonide were compared to BDP or BUD, the difference in FEV1 did not reach significance but we cannot exclude a significant effect in favour of BDP/BUD. Other lung function outcomes did not give significant differences between treatments. Paediatric quality of life scores did not differ between treatments. Adverse events occurred with similar frequency between ciclesonide and BDP/BUD. Comparison with FP at half the nominal dose was undertaken in three studies, which indicated that FEV1 was not significantly different, but was not equivalent between the treatments (per protocol: -0.05 L 95% confidence intervals -0.11 to 0.01).

AUTHORS' CONCLUSIONS

The results of this review give some support to ciclesonide as an equivalent therapy to other ICS at similar nominal doses. The studies assessed low doses of steroids, in patients whose asthma required treatment with low doses of steroids. At half the dose of FP and BDP/BUD, the effects of ciclesonide were more inconsistent The effect on candidiasis may be of importance to people who find this to be problematic. The role of ciclesonide in the management of asthma requires further study, especially in paediatric patients. Further assessment against FP at a dose ratio of 1:2 is a priority.

Ciclesonide versus placebo for chronic asthma in adults and children

BACKGROUND

Inhaled corticosteroids are an integral part of asthma management, and act as an anti-inflammatory agent in the airways of the lung. These agents confer significant benefit in terms of symptom management and improvement in lung function, but may also cause harm in terms of local and systemic side-effects. Ciclesonide is a novel steroid that has efficient distribution and release properties that mean it can be taken once daily, making it potentially useful in ongoing asthma management.

OBJECTIVES

To assess the efficacy of inhaled ciclesonide in adults and children with chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group register of trials with pre-defined terms. Additional searches of CENTRAL and PubMed were undertaken. The literature searches for this review are current up to June 2007.

SELECTION CRITERIA

Randomised parallel or crossover studies were eligible for the review. We included studies comparing ciclesonide with placebo, and we also included studies comparing ciclesonide at different doses.

DATA COLLECTION AND ANALYSIS

Two authors assessed studies for inclusion in the review, extracted data independently and checked each others' work. We contacted study investigators in order to obtain additional data. Extracted data were entered into RevMan 4.2 and analysed as fixed effect mean differences for continuous data, and fixed effect risk ratios for dichotomous data.

MAIN RESULTS

Eighteen trials (reporting 20 study comparisons) met the review entry criteria. We report findings from 18 group comparisons where data were available (6343 participants, of whom 1692 were children). Ciclesonide versus placebo: The short duration of the included studies means that there is a lack of data with respect to the impact of ciclesonide on asthma exacerbations. At doses of 100 mcg/d or less up to 400 mcg/d in mild to moderate asthma, ciclesonide improved lung function, asthma symptoms and rescue inhaler use, compared with placebo.Dose response outcomes: Comparisons of 100 versus 200 mcg/d, 100 versus 400 mcg/d and 400 versus 800 mcg/d did not yield significant differences in lung function outcomes. Adverse event data were not available in sufficient detail to permit assessment of the safety profile of this drug.

AUTHORS' CONCLUSIONS

Ciclesonide was more effective than placebo, in the short term, in improving lung function in patients with mild to moderate asthma previously treated with inhaled corticosteroids. There remain questions as to dose response, and the lack of data on the longer term impact on exacerbations and safety profile should be addressed in future studies.

Two main subtypes of wheezing illness? Evidence from the 2004 Aberdeen schools asthma survey

To compare risk factors for wheezy bronchitis (WB) and multi-trigger wheeze (MTW) in pre-pubertal children along the spectrum of disease severity. Cross-sectional survey of children aged 7-12 yr in Aberdeen city primary schools in 2004 using parent-completed questionnaires as used in surveys in 1964, 1989, 1994, and 1999. Children were grouped into five categories: no wheeze in the past three years, non-severe wheeze triggered only by a cold (non-severe WB), non-severe wheeze triggered by other factors (non-severe MTW), severe WB, or severe MTW. Severe wheeze was defined as greater than four wheezing attacks, greater than or equal to one disturbed night per week, or speech limitation in the last 12 months. Questionnaires were returned by 3271 children (57.3%), of whom 7.4% had WB (6.1% non-severe and 1.3% severe) and 17.2% had MTW (9.4% non-severe and 7.8% severe). Severe disease was more frequent in children with MTW (31.8%) than in those with WB (5.1%). Whereas the prevalence of MTW had increased since 1964, the prevalence of WB had remained stable over this period. After adjustment for confounders, age had no influence on either wheeze type, and male sex was only associated with non-severe WB [OR 1.44, 95% confidence intervals (1.03-2.02)]. In the WB group eczema or/and hay fever in the child were more strongly associated with severe wheeze [OR 3.28(1.49-7.23) vs. OR 1.84(1.31-2.60)]. In the MTW group, this association was noticeably higher than in the WB group, but did not differ much between non-severe and severe wheeze [OR 5.46(3.70-7.20) and OR 6.01(4.1-8.75) respectively]. The presence of any allergic diseases in either parent increased the odds for non-severe and severe MTW at the same level of magnitude [OR 1.92(1.38-2.68) and OR 1.92(1.34-2.76) respectively], and statistically non-significantly for severe WB [OR 1.75(0.78-3.94)]. Living in a deprived area increased both severe WB and severe MTW, reaching statistical significance only for severe MTW [OR 1.96(1.39-2.78)]. Smoking in the house was associated with increased risk of WB and MTW of any severity. WB and MTW differ in prevalence trends and severity. Within severity levels, the influence of age, allergic diseases in children and parents also differed between these two wheezing subtypes.

Variations in genetic influences on the development of asthma throughout childhood, adolescence and early adult life

PURPOSE OF REVIEW

Asthma is likely to be due to many aetiological factors, the effect of each varying considerably with age. Now that there are well established candidate genes for asthma, using genetics to examine age-related susceptibility to asthma offers a new approach to understanding the basic underlying mechanisms.

RECENT FINDINGS

Since few long-term, longitudinal asthma studies exist, opportunities to examine age-related genetic susceptibility have been limited, but have produced some specific findings. The CCR5Delta32 polymorphism renders the chemokine receptor nonfunctional and is associated with reduced asthma susceptibility in children but not adults. In CD14 C-159T, the -159C allele has been associated with increased atopy in mid-childhood, but not in young adults. IL-12beta is a promoter polymorphism associated with reduced lung function in girls but not boys in mid-childhood only. Regarding the beta(2)adrenoceptor, results from three studies suggest that Arg16 can be associated with impaired airway function in infancy and Gly16 with asthma and wheeze in mid-childhood.

SUMMARY

Age-related genetic susceptibility studies are likely to make a major contribution to understanding basic mechanisms in asthma, but the limited number of suitable cohorts has meant that to date few studies have been reported.

Perennial allergen sensitisation early in life and chronic asthma in children: a birth cohort study

BACKGROUND

Reduced lung function is a feature of chronic asthma, which becomes apparent at school age. Unknown factors between birth and school age determine the progressive loss of pulmonary function in children with persistent asthma. We investigated the role of allergic sensitisation and allergen exposure early in life.

METHODS

The German Multicentre Allergy Study followed 1314 children from birth to 13 years of age. We regularly interviewed parents about their child's asthma and measured IgE levels. Allergen exposure was assessed at age 6 months, 18 months, and at 3, 4, and 5 years; lung function was assessed at 7, 10, and 13 years; post-bronchodilator response at 10 and 13 years; and a bronchial histamine challenge was done at 7 years.

RESULTS

90% of children with wheeze but no atopy lost their symptoms at school age and retained normal lung function at puberty. By contrast, sensitisation to perennial allergens (eg, house dust mite, cat and dog hair) developing in the first 3 years of life was associated with a loss of lung function at school age. Concomitant exposure to high levels of perennial allergens early in life aggravated this process: forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio was 87.4 (SD 7.4) for those sensitised and with high exposure compared with 92.6 (6.0) for those not sensitised, p<0.0001; and maximal expiratory flow at 50% (MEF50) 86.4 (25.1) for sensitised and with high exposure compared with 101.5 (23.2; p=0.0031) for those not sensitised. Such exposure also enhanced the development of airway hyper-responsiveness in sensitised children with wheeze. Sensitisation and exposure later in life had much weaker effects and sensitisation to seasonal allergens did not play a part.

INTERPRETATION

The chronic course of asthma characterised by airway hyper-responsiveness and impairment of lung function at school age is determined by continuing allergic airway inflammation beginning in the first 3 years of life. However, children with a non-atopic wheezing phenotype lose their symptoms over school age and retain normal lung function at puberty.

A comparison of virus-associated and multi-trigger wheeze in school children

To examine differences between virus-associated wheeze and wheeze associated with other triggers (multi-trigger wheeze) in elementary school children, we performed a cross-sectional school-based questionnaire study of 5,998 children mainly 7 to 12 years of age, with outliers 6 and 13 years of age. Using parent-completed questionnaires, we identified 522 children who wheezed only during upper respiratory tract infections (virus-associated wheeze), 1,186 children who wheezed on other occasions (multi-trigger wheeze), and 4,290 children with no wheeze. In comparison with children who had multi-trigger wheeze, children with virus-associated wheeze were more likely to be male, to be younger, and to have less frequent wheezy episodes. They were less likely to have night cough, shortness of breath or chest tightness, to have a personal or parental history of atopic disorders, to have a diagnosis of asthma, or to be receiving asthma treatment. Both types of wheeze were associated with social deprivation, a relationship that persisted after controlling for family smoking. Virus-associated wheeze is a common but diminishing problem in this age group, and the differences between virus-associated wheeze and multi-trigger wheeze already noted in pre-school children persist in this older age group.

Inhaled corticosteroids for non-specific chronic cough in children

BACKGROUND

Cough in isolation of other clinical features is known as non-specific cough, which has been defined as non-productive cough in the absence of identifiable respiratory disease or any known aetiology. In children with non-specific cough the possibility of asthma being the underlying disorder is often raised (so called cough variant asthma). The proponents of cough variant asthma suggest a therapeutic trial of medications usually used to treat asthma.

OBJECTIVES

To determine the efficacy of inhaled corticosteroids in non-specific cough in children over the age of two years.

SEARCH STRATEGY

Searches were conducted on Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Searches were current as of March 2004.

SELECTION CRITERIA

All randomised (randomised and quasi-randomised) controlled clinical trials in which an inhaled corticosteroid (beclomethasone (BDP), fluticasone (FP), triamcinalone (TAA) or any other corticosteroid) were given for cough in children over two years of age were included. Two review authors independently assessed articles for inclusion and methodological quality.

DATA COLLECTION AND ANALYSIS

Data from trials was extracted by both review authors and entered into the Cochrane Collaboration software program RevMan Analyses 1.0.2.

MAIN RESULTS

Two trials met the inclusion criteria (123 participants). One compared inhaled beclomethasone dipropionate (400 micrograms per day) with placebo and the other compared fluticasone propionate (2 mg per day for 3 days followed by 1 mg per day for 11 days) with placebo. Both studies used metered dose inhalers via a spacer. With the lower dose of inhaled corticosteroid there was no significant difference between the beclomethasone and placebo groups. With the higher dose there was a significant improvement in nocturnal cough frequency after two weeks in children presenting with persistent nocturnal cough. However, a significant but smaller improvement was also seen with placebo.

AUTHORS' CONCLUSIONS

In one study beclomethasone dipropionate (400 micrograms per day) was no different from placebo in reducing the frequency of cough measured objectively or scored subjectively. There might be a small improvement with very high-dose inhaled corticosteroid but the clinical impact of this is unlikely to beneficial.

Infectious triggers of asthma

There is abundant evidence that asthma is frequently exacerbated by infectious agents. Several viruses have been implicated in the inception and exacerbation of asthma. Recent attention has been directed at the role of infections with the atypical bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae as agents capable of triggering asthma exacerbations and potentially as inciting agents for asthma. This article examines the evidence for interaction between specific infectious agents and exacerbations of asthma, including the immunopathology of infection-triggered asthma, and the current therapeutic options for management.

Classifying asthma severity in children: mismatch between symptoms, medication use, and lung function

Current guidelines for asthma care categorize asthma severity based on the frequency of asthma symptoms, medication use, and lung function measures. The objective of this study was to determine whether lung function measures are consistent with levels of asthma severity as defined by the National Asthma Education and Prevention Program/Expert Panel Report 2 Guidelines. Parents of children aged 5-18 years with asthma seen in two outpatient subspecialty clinics completed questionnaires regarding asthma medication use and symptom frequency over the preceding 1 and 4 weeks, respectively. All children performed spirometry. When asthma severity was based on the higher severity of asthma symptom frequency or medication use, asthma was mild intermittent in 6.9% of participants, mild persistent in 27.9%, moderate persistent in 22.4%, and severe persistent in 42.9%. FEV(1) % predicted did not differ by level of asthma severity. FEV(1)/FVC decreased as asthma severity increased (p < 0.0001) and was abnormal in 33% of the participants, and a greater percentage of participants had an abnormal FEV(1)/FVC as asthma severity increased (p = 0.0001). In children, asthma severity classified by symptom frequency and medication usage does not correlate with FEV(1) categories defined by National Asthma Education and Prevention Program Guidelines. FEV(1) is generally normal, even in severe persistent childhood asthma, whereas FEV(1)/FVC declines as asthma severity increases.

Associations of the IL12B promoter polymorphism in longitudinal data from asthmatic patients 7 to 42 years of age

BACKGROUND

The IL12B gene encodes the p40 chain of IL-12, a proinflammatory cytokine that antagonizes TH2 expression and hence may play a critical role in the pathogenesis of airway inflammation observed in asthma. A promoter polymorphism of the gene was recently shown to be associated with asthma severity in children but only in heterozygotes.

OBJECTIVE

The aim of the present study was to test the hypothesis that the IL12B promoter polymorphism is associated with asthma susceptibility, severity, and related phenotypes in a cohort with longitudinal phenotypic data, from childhood to adulthood.

METHODS

Four hundred one 7-year-old children (106 control children, 295 asthmatic children) and 83 10-year-old children with severe asthma were recruited from a 1957 birth cohort. Atopic status and respiratory functions were determined at ages 7, 10, 14, 21, 28, 35, and 42 years. At age 42 years, blood samples were taken from 244 individuals for genotyping and the determination of plasma IgE levels and PHA- and house dust mite-induced IFN-gamma responses. Genotyping was done by the PCR restriction fragment length polymorphism method, using Alu I, and confirmed in 10% of the samples by direct sequencing.

RESULTS

The IL12B genotypes were not associated with asthma susceptibility, severity, or atopy at ages 7 and 42 years. Total serum IgE levels at age 42 of men with at least one CTCTAA allele were higher than those homozygous for the GC allele (P = .042), whereas no difference was observed for women. At all ages, female subjects with at least 1 copy of the CTCTAA allele had lower mean percent predicted levels of FEV1 and FVC compared with those without this allele; these differences were significant at ages 10 and 14 years (P < .05) and in the asthmatic subgroup at age 7 years (P = .001).

CONCLUSIONS

In this long-term study of asthmatic subjects with comprehensive data on asthma severity, we found no evidence to support the presence of a heterozygote effect of the IL12B promoter polymorphism on the level of asthma in early childhood or adulthood. The polymorphism was also not associated with asthma susceptibility, but the CTCTAA allele may have been associated with elevated serum IgE levels in male subjects and reduced pulmonary function in female subjects in early childhood.

Development of pediatric pulmonology in the United Kingdom, Europe, and Australasia

The organization of medicine in Europe, the UK and the Commonwealth countries was always much less formal than in the USA for many years and pediatricians interested in pediatric lung disease and asthma often started off as adult internists or specialists in adult pulmonary medicine. The early leaders in developing a special interest in the breathing of children during the 1940s and 1950s were predominantly physiologists and clinicians who began to apply physiological techniques to the study lung function in healthy and sick infants and children. A major contribution to our understanding of the epidemiology of wheezing in children was the early establishment of a cohort study in Australia which is still yielding important information. It was during the early 1970s that pediatric pulmonary "politics" began to emerge in the UK when pediatricians interested in lung diseases began to arrange an informal society and meet regularly under the auspices of the British Paediatric Association. In fairly characteristic fashion, pulmonology in Europe was represented for a while by several different societies but due to the efforts of some dedicated enthusiasts there finally emerged the Paediatric Assembly of the European Respiratory Society (ERS) and its first Head, Max Zach, went to become President of the ERS itself. Despite some early doubts abut the future for pediatric pulmonology as a specialty in Europe and Australasia it is clearly flourishing as shown by the rising membership of the professional societies and the constant stream of high quality basic science and clinical publications.

Wheezy bronchitis in childhood: a distinct clinical entity with lifelong significance?

BACKGROUND

Historically, clinicians have recognized the existence of the clinical syndrome of childhood wheezy bronchitis. In the late 1960s, children with this syndrome were relabeled as having asthma, and the term wheezy bronchitis was abandoned. In a 1989 study of a cohort that originally had been studied in 1964, we reported that those who had childhood wheezy bronchitis had as adults attained lung function similar to that of healthy control subjects and had less significant symptoms than did those who had experienced childhood asthma, in whom lung function was reduced. In this study, we reexamined these subjects 12 years later to determine whether the improved outcome of the wheezy bronchitis group had been maintained.

METHODS

In 2001, we followed up the 283 participants of the 1989 study, who were now aged 45 to 50 years. In interviews, respiratory symptoms and smoking status were assessed. Spirometry was measured.

RESULTS

One hundred seventy-seven subjects (63%) completed the study. After adjusting for age, height, gender, socioeconomic status, smoking status, and number of pack-years smoked, the current FEV(1) in the childhood asthma group (mean, 2.45 L; 95% confidence interval, 2.29 to 2.62) was significantly lower than the wheezy bronchitis group (2.78 L, 95% confidence interval, 2.64 to 2.91; p < 0.01) and the control group (2.96 L; 95% confidence interval, 2.83 to 3.1; p < 0.01). The difference between the wheezy bronchitis group and the control subjects was not significant (p = 0.06). Between 1989 and 2001, both the childhood wheezy bronchitis group (p < 0.01) and the childhood asthma group (p = 0.01) had greater declines in FEV(1) than did the control group (asthma group decline, - 0.75 L [95% confidence interval, - 0.66 to - 0.84]; wheezy bronchitis group decline, - 0.75 L [95% confidence interval, - 0.68 to - 0.83]; control group decline, - 0.59 L [95% confidence interval, - 0.52 to - 0.67]). In 2001, the asthma group had more symptoms than did the wheezy bronchitis group (p < 0.01), who were more symptomatic than the control group (p < 0.01).

CONCLUSION

Those with childhood wheezy bronchitis, having achieved normal lung function in earlier adulthood, now show a more rapid decline in lung function than did control subjects. If this rate of decline persists, these subjects may develop obstructive airways disease in later life.

Natural history of asthma

For some children, asthma is a disease whose symptoms seem to remit with time. Numerous children, however, develop disease that is persistent throughout their lifetimes and is associated with more severe symptoms, increased airway reactivity, and loss of lung function. These children typically have a family history of asthma and demonstrate increased airways reactivity and atopy in childhood. A clearer picture of the natural history of asthma in the developing child has been derived from the results of several longitudinal studies. Although some questions have been clarified, several questions still remain. Now that the incidence and severity of asthma seem to be increasing, children born in the last 10 years may experience more severe disease or a different pathophysiology than those born 30 to 40 years ago. New cohort studies are needed to assess this possibility. Additional investigations into the genetics of asthma causation will help elucidate the different phenotypic expressions of this complex disease. Once these different phenotypic groups can be identified early in life, further studies can be performed to explore the impact of therapeutic intervention on the severity of asthma symptoms and loss of lung function.

[Risk factors for early bronchiolitis at asthma during childhood: case-control study of asthmatics aged 4 to 12 years]

The group of general paediatrics of the French Paediatrics Society conducted a case-control study in order to verify the link between the occurrence of an acute bronchiolitis early during the first year of life, more specifically during the first trimester, and asthma during later childhood.

METHODS

Parents of 4-to-12-year-old children answered a questionnaire during a general paediatrics visit. Exposition was attested by a diagnosis of bronchiolitis mentioned on the personal health record of the child. Environmental factors and medical history, obtained from the parents and by checking the health record of the child, were studied using multivariate analysis.

RESULTS

Nineteen paediatricians included 80 children with asthma and 160 controls. Fifty-four per cent of asthmatic children had a medical history of bronchiolitis during the first year of life versus 17% of control children (P < 0.001). Mean age of bronchiolitis occurrence was 6.6 months in both groups (P = 0.98). Multivariate analysis showed that occurrence of bronchiolitis during the first year of life was significantly more frequent in asthmatic children (P < 0.001, OR = 5.6, IC95 = [2.6-11.6]) but this effect was not observed during the first trimester of life.

CONCLUSION

Bronchiolitis during the first year of life was significantly related to later asthma in 4-to-12-year-old children treated by general paediatricians. On the other hand, a very early bronchiolitis during the first trimester of life did not appear, in our set of data, as a contributive factor to explain asthma in later childhood.

Long-term outcome of childhood asthma

What we know: The outcome of childhood asthma is dependent on the pattern of asthma through childhood. Episodic asthma in childhood tends to resolve in adolescence and through mid-adult years, with no impairment of lung function. Persistent asthma in childhood is more likely to persist into adult years, with modest impairment of lung function. The impairment of lung function occurs early in the disease process and is not progressive, despite continuing symptoms. What we need to know: Are there clearly identifiable phenotypes of childhood asthma that have different aetiologies, response to treatment, genotypes and natural history? Does early treatment with anti-inflammatory agents prevent impairment of lung function? Can an algorithm be developed to predict the likelihood of persistent asthma on first presentation?

Angiogenesis in paediatric airway disease

A number of characteristic changes occur in the bronchial wall in paediatric airway diseases. The process of remodelling is usually associated with specific changes to the vasculature, resulting in an increase in vessel numbers, vasodilatation, vessel leakage and cellular margination with transmigration to target tissues. This combined action in conditions such as asthma, cystic fibrosis and bronchiolitis lead to airway wall thickening and reduced airflow. Each component of the vascular response has been shown to be controlled by a range of inflammatory mediators and growth factors. These factors are regulated by a complex process involving gene expression, transcription and translation at the molecular level, protein release, binding to matrix elements and receptors on endothelial cells, then the endothelial response itself. A number of commonly used airway medications are potentially capable of modulating the vascular response to inflammatory stimuli. New therapies may be able to improve airflow through better regulation of vessel growth, dilatation and leakage in the airway wall.

The Melbourne Asthma Study: 1964-1999

A group of children with a past history of wheezing was randomly selected from the Melbourne community at the age of 7 years in 1964, and a further group of children with severe wheezing was selected from the same birth cohort at the age of 10 years. These subjects have been followed prospectively at 7-year intervals, with the last review in 1999, when their average age was 42 years. Eighty-seven percent of the original cohort who were still alive participated in the 1999 review. This study showed that the majority of children who had only a few episodes of wheezing associated with symptoms of a respiratory infection had a benign course, with many ceasing to wheeze by adult life. Most who continued with symptoms into adult life were little troubled by them. Conversely, those children with asthma mostly continued with significant wheezing into adult life, and the more troubled they were in childhood, the more likely symptoms continued. There was a loss in lung function by the age of 14 years in those with severe asthma, but the loss did not progress in adult life. The childhood asthma had been treated before the availability of inhaled steroids. There was no significant loss of lung function in those with milder symptoms.