Definition, assessment and treatment of wheezing disorders in preschool children: an evidence-based approach

Obstruktive Atemwegserkrankungen

In den folgenden Abschnitten werden die verschiedenen Formen der obstruktiven Atemwegserkrankungen erläutert, die je nach Alter, prädisponierenden Risikofaktoren und auch je nach Art der Auslöser verschiedenartige Ausprägungen und Verlaufsformen (Phänotypen) annehmen können.

Childhood asthma: diagnosis and treatment

Many children suffer from recurrent coughing, wheezing and chest tightness. In preschool children one third of all children have these symptoms before the age of six, but only 40% of these wheezing preschoolers will continue to have asthma. In older school-aged children the majority of the children have asthma. Quality of life is affected by asthma control. Sleep disruption and exercised induced airflow limitation have a negative impact on participation in sports and social activities, and may influence family life. The goal of asthma therapy is to achieve asthma control, but only a limited number of patients are able to reach total control. This may be due to an incorrect diagnosis, co-morbidities or poor inhalation technique, but in the majority of cases non-adherence is the main reason for therapy failures. However, partnership with the parents and the child is important in order to set individually chosen goals of therapy and may be of help to improve control. Non-pharmacological measures aim at avoiding tobacco smoke, and when a child is sensitised, to avoid allergens. In pharmacological management international guidelines such as the GINA guideline and the British Guideline on the Management of Asthma are leading.

A foreign body aspiration in a preschool child mimicking a multitrigger wheezing: a case report and review of the literature

We report a child with a history of recurrent episodes of wheezing. At 3 months of age, the frequency of these episodes began to increase. Wheezing was associated with persistent cough and dyspnea with nocturnal awakening. The skin prick test was positive for pollen and pet dander. Airway endoscopy revealed the presence of a peanut, which obstructed the left main bronchus. Chronic cough and recurrent wheezing with symptoms between acute exacerbations could be signs not only of asthma but also of other disorders. Therefore, coexisting conditions should be evaluated whenever symptoms seem to be unusually severe or frequent.

Environmental exposures and respiratory outcomes in children

Asthma is a complex condition where genetic and environmental interactions occur at critical periods in development. The focus of this review was the role of environmental exposures on asthma causation. Selected studies published in 2010 and 2011 were reviewed to illustrate the challenge in relating environmental exposure(s) on asthma causation and also to focus on some exposures currently thought to be important to asthma pathogenesis. Challenges in understanding how environmental exposures may translate into asthma causation are summarised. Inhaled and ingested exposures are described, including microbial products, swimming pools, diet and antenatal tobacco exposure. A final synthesis summarises what is currently understood about childhood asthma causation and what advice might be given to parents and governments interested in reducing asthma risk.

Fish consumption in infancy and asthma-like symptoms at preschool age

OBJECTIVE

To assess whether timing of introduction of fish and the amount of fish consumption in infancy were associated with asthmalike symptoms at preschool age.

METHODS

This study was embedded in the Generation R study (a population-based birth cohort in Rotterdam, Netherlands). At the age of 12 and 14 months, timing of introduction of fish into the infant's diet was assessed. The amount of fish consumption at 14 months was assessed by a semiquantitative food frequency questionnaire. Presence of asthmalike symptoms in the past year was assessed at the child's age of 36 and 48 months.

RESULTS

Relative to no introduction in the first year of life, introduction between age 6 and 12 months was significantly associated with a lower risk of wheezing at 48 months (odds ratio [OR]: 0.64; 95% CI: 0.43-0.94). When compared with introduction between 6 and 12 months, no introduction in the first year and introduction between 0 and 6 months were associated with an increased risk of wheezing at 48 months (OR: 1.57; 95% CI: 1.07-2.31 and OR: 1.53; 95% CI: 1.07-2.19, respectively). The amount of fish at age 14 months was not associated with asthmalike symptoms (P > .15).

CONCLUSIONS

Introduction of fish between 6 and 12 months but not fish consumption afterward is associated with a lower prevalence of wheezing. A window of exposure between the age of 6 and 12 months might exist in which fish might be associated with a reduced risk of asthma.

Challenges in treating pediatric asthma in developing countries

Asthma is the most common chronic disease in children in many low- and middle-income countries. In these settings, the burden of childhood asthma is increasing and is associated with severe disease. There are a number of challenges to providing optimal management of childhood asthma in such settings. These include under-diagnosis of childhood asthma, access to care, ability of healthcare workers to manage asthma, availability and affordability of inhaled therapy, environmental control of potential triggers, education of healthcare providers and of the public, and cultural or language issues. International and national guidelines for childhood asthma have been produced, but implementation remains a real challenge. Access to and affordability of essential inhaled asthma drugs, especially low-dose inhaled corticosteroids and short-acting bronchodilators, are major challenges to effective asthma control in many countries. A low-cost spacer made from a plastic bottle is effective for use with a metered-dose inhaler, but use must be included in asthma educational initiatives. Educational programs for healthcare personnel and for the public that are culturally and language appropriate are needed for effective implementation of asthma guidelines. Socioeconomic and structural barriers to care within health services remain obstacles to achieving optimal treatment of asthma for many children.

Assessment of airflow limitation, airway inflammation, and symptoms during virus-induced wheezing episodes in 4- to 6-year-old children

Background

It is disputed whether recurrent episodes of wheeze in preschool-aged children comprise a distinct asthma phenotype.

Objective

We sought to prospectively assess airflow limitation and airway inflammation in children 4 to 6 years old with episodic virus-induced wheeze.

Methods

Ninety-three children 4 to 6 years old with a history of mild, virus-induced episodes of wheeze who were able to perform acceptable fraction of exhaled nitric oxide (Feno) maneuvers and spirometry (with forced expiratory time ≥0.5 seconds) were followed prospectively. Lung function and Feno values were measured every 6 weeks (baseline) within the first 48 hours of an acute wheezing episode (day 0) and 10 and 30 days later. Symptom scores and peak flow measurement were recorded daily.

Results

Forty-three children experienced a wheezing episode. At day 0, Feno values were significantly increased, whereas forced expiratory volume at 0.5 seconds (FEV_0.5) significantly decreased compared with baseline (16 ppb [interquartile range {IQR}, 13-20 ppb] vs 9 ppb IQR, 7-11 ppb] and 0.84 L [IQR, 0.75-0.99 L] vs 0.99 L [IQR, 0.9-1.07 L], respectively; both P < .001). Airflow limitation at day 0 was reversible after bronchodilation. FEV_0.5 and Feno values were significantly associated with each other and with lower and upper respiratory tract symptoms when assessed longitudinally but not cross-sectionally at all time points independently of atopy. Feno and FEV_0.5 values returned to baseline levels within 10 days.

Conclusions

Mild episodes of wheeze in preschoolers are characterized by enhanced airway inflammation, reversible airflow limitation, and asthma-related symptoms. Feno values increase significantly during the first 48 hours and return to personal baseline within 10 days from the initiation of the episode. Longitudinal follow-up suggests that symptoms, inflammation, and lung function correlate well in this phenotype of asthma.

Analyzing atopic and non-atopic asthma

There is a need to better define phenotypes of asthma. However, many studies have data available only on asthma and atopy, so they are often used to define ‘atopic’ and ‘non-atopic’ asthma. We discuss and illustrate the problems of analyzing such outcomes. We used the 31 year follow-up of the Northern Finland Birth Cohort 1966 (n=5,429). ‘Atopic asthma’ and ‘non-atopic asthma’ were defined based on presence or absence of atopy (any skin prick test ≥3 mm) at age 31. Gender and ownership of cat in childhood were used as risk factors. Simple calculations on hypothetical datasets were used to support the conclusions. ‘Atopic asthma’ and ‘non-atopic asthma’, are not well separated disease entities. The association of a risk factor with ‘atopic asthma’ and ‘non-atopic asthma’ is determined both by its association with asthma and with atopy. E.g. if a risk factor is not associated with asthma, but is protective for atopy, this will produce a protective association with ‘atopic asthma’, but an opposite association with ‘non-atopic asthma’. This is the result from the typical analysis, which uses all non-asthmatics as the comparison group. Valid results, unconfounded by atopy, can be gained by comparing asthmatics to nonasthmatics separately among atopics and non-atopics, i.e. by doing the analysis stratified by atopy. If data only on asthma and atopy are available, asthma and atopy should be analyzed at first as separate outcomes. If atopic and nonatopic asthma are used as additional outcomes, valid results can be gained by stratifying the analysis by atopy.

Maternal obesity, gestational weight gain, and risk of asthma and atopic disease in offspring: a study within the Danish National Birth Cohort

BACKGROUND

High pre-pregnancy body mass index (BMI) and excessive gestational weight gain (GWG) are suggested to influence risk of asthma and atopic disease in offspring.

OBJECTIVE

We examined the effect of BMI and GWG on risk of asthma, wheezing, atopic eczema (AE), and hay fever in children during the first 7 years of life.

METHODS

This was a cohort study of 38,874 mother-child pairs from the Danish National Birth Cohort (enrollment 1996-2002) with information from the 16th week of pregnancy and at age 6 months, 18 months, and 7 years of the child. Odds ratios (ORs) with 95% CIs were calculated by logistic regression with adjustment for potential confounders.

RESULTS

During the first 7 years of life, 10.4% of children developed doctor-diagnosed asthma, 25.8% AE, and 4.6% hay fever. Maternal BMI and to a lesser extent GWG were associated with doctor-diagnosed asthma ever. In particular, BMI≥35 (adjusted OR, 1.87; 95% CI, 0.95-3.68) and GWG≥25 kg (adjusted OR, 1.97; 95% CI, 1.38-2.83) were associated with current severe asthma at age 7 years. Maternal BMI was also associated with wheezing in offspring, with the strongest association observed between BMI≥35 and late-onset wheezing (adjusted OR, 1.87; 95% CI, 1.28-2.73). Maternal BMI and GWG were not associated with AE or hay fever.

CONCLUSIONS

Maternal obesity during pregnancy was associated with increased risk of asthma and wheezing in offspring but not with AE and hay fever, suggesting that pathways may be nonallergic.

Leukocytes from wheezing infants release lower amounts of IL-12 and IFN-γ compared to non-wheezing infants

OBJECTIVE

This study investigated environmental endotoxin exposure during early life, sensitization to aeroallergens, the production of cytokines by LPS-stimulated leukocytes, and the development of a wheezing phenotype in a prospective cohort of infants with high risk of developing allergic diseases.

MATERIALS AND METHODS

Eighty-four infants were followed from birth until 30 months of age. We assessed endotoxin concentration in house dust of their homes during the first 6 months of life. At age 30 months they were clinically evaluated to determine the development of wheezing and other clinical events, were skin prick tested, and had blood samples collected for the evaluation of cytokine release by LPS-stimulated peripheral blood mononuclear cells (PBMC).

RESULTS

The level of endotoxin exposure during early life was not associated with development of a wheezing phenotype. On the other hand a higher incidence of respiratory infections occurred among recurrent wheezing (RW) infants. PBMC from RW children exposed to higher levels of environmental endotoxin (above 50 EU/mg) released less Interleukin (IL)-12p70 and IFN-γ compared to the non-RW group. TNF-α, IL-10, IL-4, IL-5, and IL17 production by LPS-stimulated PBMC from RW and non-RW children was equivalent in both groups of environmental endotoxin exposure.

CONCLUSION

In this prospective cohort of infants with high risk of developing allergic diseases we observed that RW and non-RW children were exposed to similar levels of endotoxin early in life. LPS-stimulated PBMC from RW infants exposed to higher levels of endotoxin released significantly less IL-12 and IFN-γ compared to non-RW infants.

Risk factors and characteristics of respiratory and allergic phenotypes in early childhood

BACKGROUND

Unsupervised approaches can be used to analyze complex respiratory and allergic disorders.

OBJECTIVE

We investigated the respiratory and allergic phenotypes of children followed in the Pollution and Asthma Risk: An Infant Study (PARIS) birth cohort.

METHODS

Information on respiratory and allergic disorders, medical visits, and medications was collected during medical examinations of children at 18 months of age; biomarker data were also collected (total and allergen-specific IgE levels and eosinophilia). Phenotypes were determined by using latent class analysis. Associated risk factors were determined based on answers to questionnaires about environmental exposures.

RESULTS

Apart from a reference group, which had a low prevalence of respiratory symptoms or allergies (n=1271 [69.4%]), 3 phenotypes were identified. On the basis of clinical signs of severity and use of health care resources, we identified a mild phenotype (n=306 [16.7%]) characterized by occasional mild wheeze and 2 severe phenotypes separated by atopic status. The atopic severe phenotype (n=59 [3.2%]) included 49 (83%) children with wheezing and was characterized by a high prevalence of atopy (61% with allergenic sensitization) and atopic dermatitis (78%). In contrast, atopy was rare among children with the nonatopic severe phenotype (n=195 [11%]); this group included 88% of the children with recurrent wheezing. Risk factors for respiratory disease included parental history of asthma, male sex, siblings, day care attendance, exposure to tobacco smoke or molds, indoor renovations, and being overweight, although these factors did not have similar affects on risk for all phenotypes.

CONCLUSION

Atopy should be taken into account when assessing the risk of severe exacerbations (that require hospital-based care) in wheezing infants; precautions should be taken against respiratory irritants and molds and to prevent children from becoming overweight.

Childhood asthma in low income countries: an invisible killer?

Bacterial pneumonia has hitherto been considered the key cause of the high respiratory morbidity and mortality in children under five years of age (under-5s) in low-income countries, while asthma has not been stated as a significant reason. This paper explores the definitions and concepts of pneumonia and asthma/wheezing/bronchiolitis and examines whether asthma in under-5s may be confused with pneumonia. Over-diagnosing of bacterial pneumonia can be suspected from the limited association between clinical pneumonia and confirmatory test results such as chest x-ray and microbiological findings and poor treatment results using antibiotics. Moreover, children diagnosed with recurrent pneumonia in infancy were often later diagnosed with asthma. Recent studies showed a 10-15% prevalence of preschool asthma in low-income countries, although under-5s with long-term cough and difficulty breathing remain undiagnosed. New studies demonstrate that approximately 50% of acutely admitted under-5s diagnosed with pneumonia according to Integrated Management of Childhood Illnesses could be re-diagnosed with asthma or wheezing when using re-defined diagnostic criteria and treatment. It is hypothesised that untreated asthma may contribute to respiratory mortality since respiratory syncytial virus (RSV) is an important cause of respiratory death in childhood, and asthma in under-5s is often exacerbated by viral infections, including RSV. Furthermore, acute respiratory treatment failures were predominantly seen in under-5s without fever, which suggests the diagnosis of asthma/wheezing rather than bacterial pneumonia. Ultimately, underlying asthma may have contributed to malnutrition and fatal bacterial pneumonia. In conclusion, preschool asthma in low-income countries may be significantly under-diagnosed and misdiagnosed as pneumonia, and may be the cause of much morbidity and mortality.

Role of leukotriene receptor antagonists in the management of pediatric asthma: an update

At present, the main indications for leukotriene receptor antagonists (LTRA) in pediatric asthma are as add-on therapy to inhaled corticosteroids (ICS) and as initial controller therapy in children with mild asthma, especially those who cannot or will not use ICS. LTRA are also useful for patients who have concomitant rhinitis, and patients with viral-induced wheeze and exercise-induced asthma. It should be noted that the benefits of LTRA therapy have been demonstrated in children as young as 6 months of age and recent clinical trials have further proven the benefits of LTRA in acute asthma exacerbations. However, considering the important pro-inflammatory effects that leukotrienes (LT) have in experimental models of asthma, it may seem surprising that LTRA treatment outcomes are not better and that in some clinical trials only a minority of patients could be classified as full responders. This could be explained by potential additional LT receptors that are not affected by LTRA. Such receptors could represent new therapeutic targets in asthma. Furthermore, progress in differentiating between asthma phenotypes that result from different pathogenic mechanisms, some of which may involve LT to a lesser degree, should lead to an improved, personalized use of LTRA for treating asthma.

Quantification of shape of flow-volume loop of healthy preschool children and preschool children with wheezing disorders

BACKGROUND

The earliest change associated with airflow obstruction in small airways is reflected in a concave shape on the maximum expiratory flow-volume loop (MEFVL). The shape of the MEFL changes with age but reference values for curvilinearity indices (CI) for preschool children have not been published. We aimed to describe the normal curvilinearity of healthy preschool MEFVL by CI (the β angle and the ratio of maximum expiratory flow when 50% of forced vital capacity remains to be expired/peak expiratory flow (MEF(50%) /PEF)) and to test their capacity in detecting concavity in preschool children with wheezing disorders.

METHODS

Spirometric data were obtained from 132 healthy preschool children and 171 3-to-5-year-old preschool children with wheezing disorders and reference values for CI calculated.

RESULTS

Mean (SD) β angle of healthy children was 203° (16°) and mean MEF(50%) /PEF of healthy children was 0.71 (0.12) indicating convexity of MEFVL, both decreased with increasing age (P = 10(-4) ). Children with wheezing disorders had lower z-score values of CI (P ≤ 10(-6) ) indicating more concave MEFVL. Among the two CI, MEF(50%) /PEF allowed for the best discrimination between healthy children and children with wheezing disorders (Wilks' lambda = 0.898, P = 10(-7) ).

CONCLUSION

These CI can detect and quantify the concavity of the descending limb of the MEFVL in preschool children with wheezing disorders, MEF(50%) /PEF having the highest sensitivity in detecting the concavity.

High physician adherence to phenotype-specific asthma guidelines, but large variability in phenotype assessment in children

BACKGROUND

The implementation of international pediatric asthma guidelines hinges on the distinction between intermittent and persistent phenotypes and the prescription of recommended phenotype-specific pharmacotherapy.

OBJECTIVES

To ascertain key factors associated with specialist-confirmed phenotype and document physicians' adherence to practice recommendations in an academic pediatric asthma center.

DESIGN/METHODS

Using electronic health records, we identified a cohort of children aged 1-17 years who presented to a tertiary-care asthma center between 2002 and 2007 and received a diagnosis of asthma from a pediatric specialist. Outcomes included: determinants of phenotypes and conformity with phenotype-specific treatment recommendations.

RESULTS

Of the 3490 eligible children (11,119 visits), most (47%) were preschoolers, 35% were 6-11 years and 18%, 13-17 years. Of children with confirmed asthma, 59% were classified on presentation as having intermittent, 41% as persistent, asthma. The within-patient phenotype varied over time with a consistency index of 0.76 (best=1); the latter was significantly lower in preschoolers than older children (p<0.0001). The persistent phenotype was highly physician-dependent; it was also positively associated with child's age, asthma severity, multiple triggers, calendar year, and duration of follow-up. Compared to 33% of children with intermittent asthma, 82% of those with persistent asthma were prescribed a maintenance controller, most as monotherapy; combination therapy was usually prescribed after a trial of monotherapy.

CONCLUSION

Pediatric asthma specialists were highly adherent to phenotype-specific pharmacotherapy. However, even in an academic center, the notable degree of intra-patient and between-physician variation in phenotype, particularly in preschoolers, was an important impediment to prescribing a maintenance controller. The findings underline the importance of developing validated and standardized means of assessing phenotypes, applicable to the whole pediatric age spectrum.

'Recurrent lower respiratory tract infections' - going around in circles, respiratory medicine style

Recurrent lower respiratory tract infections are very common in childhood, particularly the pre-school years. The term lower respiratory tract infection [LTRI] is, as with many terms used in respiratory medicine, used very loosely and carries little more information than the often decried term 'chest infections'. LRTIs should more accurately be characterised by the type of infection [viral or bacterial], the site of infection [conducting airways, or respiratory compartment or both - bronchitis/pneumonia/bronchopneumonia], the nature of the episode [acute or acute on chronic (exacerbation)], the interaction with co-morbidities such as asthma. The limited nature of the responses of the lower airways to any insult whether it is infective or irritation due to inhaled or aspirated chemicals means that almost any aetiology can lead to cough, shortness of breath and noisy breathing. We lack good non-invasive techniques to study the nature of the inflammation in the lower airways and hence the cause of chronic and recurrent symptoms in patients is frequently mis-diagnosed.

Evaluating the child with recurrent lower respiratory tract infections

We review the limited available evidence on underlying causes of recurrent pneumonia in children, supplemented by our own clinical experience. Diagnosing recurrent pneumonia in children is difficult. Diagnostic confusion is possible with recurrent upper respiratory tract infections and asthma. In our series of children with recurrent pneumonia, we never identified asthma as an underlying cause. Because the frequency or severity of recurrent pneumonia does not always justify additional invasive investigations, the diagnostic work-up may be incomplete in a number of cases. This may help to explain why an underlying cause for recurrent pneumonia cannot be found in approximately 30% of cases. Finally, the paradigm that recurrent pneumonia in the same lung lobe has a differential diagnosis different from those recurring in multiple lobes was not borne out in our case series. A stepwise and pragmatic approach to evaluating children with recurrent lower respiratory tract infections is recommended.

Association between obesity and asthma in Japanese preschool children

Obesity may increase the risk of subsequent asthma. We have previously reported that there is a clear association between obesity and asthma in Japanese school-aged children. To evaluate whether a similar association exists in younger children, a nationwide cross-sectional questionnaire-based survey was performed focusing on children aged 4-5 yr. A child who had experienced wheezing during the past 12 months and had ever been diagnosed with asthma by a physician was defined as having current asthma. Overweight and underweight were defined as BMI ≥90th percentile and ≤10th percentile, respectively, according to the reference values for Japanese children from 1978 to 1981. After excluding 2547 children because of incomplete data, 34,699 children were analyzed. Current asthma was significantly more prevalent in overweight children compared with underweight and normal weight children (13.2% for overweight vs. 10.5% for underweight and 11.1% for normal weight; both p < 0.001). Even after adjusting for other variables, such as gender, other coexisting allergic diseases, and parental history of asthma, there was an association between overweight and current asthma (adjusted odds ratio: 1.23, 95% CI: 1.10-1.38, p < 0.001). Even in preschool children, obesity is already associated with asthma, and there was no gender effect on this association. Physicians should consider the impact of obesity when managing asthma in younger children.

Assessment of controversial pediatric asthma management options using GRADE

OBJECTIVES

To develop explicit and transparent recommendations on controversial asthma management issues in children and to illustrate the usefulness of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach in rating the quality of evidence and strength of recommendations.

METHODS

Health care questions were formulated for 3 controversies in clinical practice: what is the most effective treatment in asthma not under control with standard-dose inhaled corticosteroids (ICS; step 3), the use of leukotriene receptor antagonist for viral wheeze, and the role of extra fine particle aerosols. GRADE was used to rate the quality of evidence and strength of recommendations after performing systematic literature searches. We provide evidence profiles and considerations about benefit and harm, preferences and values, and resource use, all of which played a role in formulating final recommendations.

RESULTS

By applying GRADE and focusing on outcomes that are important to patients and explicit other considerations, our recommendations differ from those in other international guidelines. We prefer to double the dose of ICS instead of adding a long-acting β-agonist in step 3; ICS instead of leukotriene receptor antagonist are the first choice in preschool wheeze, and extra fine particle ICS formulations are not first-line treatment in children with asthma. Recommendations are weak and based on low-quality evidence for critical outcomes.

CONCLUSIONS

We provide systematically and transparently developed recommendations about controversial asthma management options. Using GRADE for guideline development may change recommendations, enhance guideline implementation, and define remaining research gaps.

Severe chronic allergic (and related) diseases: a uniform approach--a MeDALL--GA2LEN--ARIA position paper

Concepts of disease severity, activity, control and responsiveness to treatment are linked but different. Severity refers to the loss of function of the organs induced by the disease process or to the occurrence of severe acute exacerbations. Severity may vary over time and needs regular follow-up. Control is the degree to which therapy goals are currently met. These concepts have evolved over time for asthma in guidelines, task forces or consensus meetings. The aim of this paper is to generalize the approach of the uniform definition of severe asthma presented to WHO for chronic allergic and associated diseases (rhinitis, chronic rhinosinusitis, chronic urticaria and atopic dermatitis) in order to have a uniform definition of severity, control and risk, usable in most situations. It is based on the appropriate diagnosis, availability and accessibility of treatments, treatment responsiveness and associated factors such as comorbidities and risk factors. This uniform definition will allow a better definition of the phenotypes of severe allergic (and related) diseases for clinical practice, research (including epidemiology), public health purposes, education and the discovery of novel therapies.

International consensus on (ICON) pediatric asthma

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Diet for the prevention of asthma and allergies in early childhood: much ado about something?

In the last decades there has been an increase in allergic disease throughout the world, particularly in children. Attempts have been made to identify the causes of this "allergy epidemic" in environmental changes and changes in population hygiene, lifestyle, socioeconomic level, and eating habits that would exert epigenetic effects. Dietetic hypotheses have been mainly focussed in long-chain polyunsaturated fatty acids, vitamin D, antioxidants, Mediterranean diet, and fruits, vegetables and fish consumption. Although the data suggest a certain association between diet and the development of asthma/allergy, there is no evidence that diet has an impact upon the prevalence of such diseases after early infancy. If indeed there is such an impact, it is likely to be confined to the prenatal period and the first months of life - when it is still possible to modulate the development of the respiratory, digestive and immune systems. Thus, once the most appropriate preventive measures have been defined, these should be implemented during pregnancy and lactation. The existing scientific evidence is unable to recommend any primary preventive measure in the general population or in different population subgroups. Special or restrictive diets in pregnant or nursing women are not indicated. Exclusive breastfeeding for six months is questioned, since solid foods should begin to be introduced at around four months of age. Once the atopic process has started, no nutritional strategies have been found to be effective as secondary or tertiary preventive measures. Longitudinal studies in cohorts of pregnant women or newborn infants could help clarify these issues.

Farming environments and childhood atopy, wheeze, lung function, and exhaled nitric oxide

BACKGROUND

Previous studies have demonstrated that children raised on farms are protected from asthma and allergies. It is unknown whether the farming effect is solely mediated by atopy or also affects nonatopic wheeze phenotypes.

OBJECTIVE

We sought to study the farm effect on wheeze phenotypes and objective markers, such as lung function and exhaled nitric oxide, and their interrelation with atopy in children.

METHODS

The GABRIEL Advanced Studies are cross-sectional, multiphase, population-based surveys of the farm effect on asthma and allergic disease in children aged 6 to 12 years. Detailed data on wheeze, farming exposure, and IgE levels were collected from a random sample of 8023 children stratified for farm exposure. Of those, another random subsample of 858 children was invited for spirometry, including bronchodilator tests and exhaled nitric oxide measurements.

RESULTS

We found effects of exposure to farming environments on the prevalence and degree of atopy, on the prevalence of transient wheeze (adjusted odds ratio, 0.78; 95% CI, 0.64-0.96), and on the prevalence of current wheeze among nonatopic subjects (adjusted odds ratio, 0.45; 95% CI, 0.32-0.63). There was no farm effect on lung function and exhaled nitric oxide levels in the general study population.

CONCLUSIONS

Children living on farms are protected against wheeze independently of atopy. This farm effect is not attributable to improved airway size and lung mechanics. These findings imply as yet unknown protective mechanisms. They might include alterations of immune response and susceptibility to triggers of wheeze, such as viral infections.

Update on leukotriene receptor antagonists in preschool children wheezing disorders

Asthma is the most common chronic disease in young children. About 40% of all preschool children regularly wheeze during common cold infections. The heterogeneity of wheezing phenotypes early in life and various anatomical and emotional factors unique to young children present significant challenges in the clinical management of this problem. Anti-inflammatory therapy, mainly consisting of inhaled corticosteroids (ICS), is the cornerstone of asthma management. Since Leukotrienes (LTs) are chemical mediators of airway inflammation in asthma, the leukotriene receptor antagonists (LTRAs) are traditionally used as potent anti-inflammatory drugs in the long-term treatment of asthma in adults, adolescents, and school-age children. In particular, montelukast decreases airway inflammation, and has also a bronchoprotective effect. The main guidelines on asthma management have confirmed the clinical utility of LTRAs in children older than five years. In the present review we describe the most recent advances on the use of LTRAs in the treatment of preschool wheezing disorders. LTRAs are effective in young children with virus-induced wheeze and with multiple-trigger disease. Conflicting data do not allow to reach definitive conclusions on LTRAs efficacy in bronchiolitis or post-bronchiolitis wheeze, and in acute asthma. The excellent safety profile of montelukast and the possibility of oral administration, that entails better compliance from young children, represent the main strengths of its use in preschool children. Montelukast is a valid alternative to ICS especially in poorly compliant preschool children, or in subjects who show adverse effects related to long-term steroid therapy.

Pediatric asthma phenotypes

PURPOSE OF REVIEW

There is currently limited ability to identify which infants and young children with recurrent wheezing will ultimately develop persistent asthma. In addition, it is not clear how risk factors influence the development of asthma in later childhood and adulthood. This review will discuss efforts to categorize these children with recurrent wheezing and develop asthma-predictive tools.

RECENT FINDINGS

Transient and persistent wheezing phenotypes have been identified with atopy, reduced lung function, and viral and bacterial respiratory infection as major risk factors for persistence of asthma. Children with severe asthma tend to have greater magnitude of atopy and lower lung function than those with mild-moderate asthma. These phenotypes and risk factors have been described in previous studies and are supported by the recent literature.

SUMMARY

Heterogeneity of wheezing phenotypes may account for different responses to treatment and varied outcomes. Overlap in phenotypes and instability over time also add additional challenges to defining discrete groups of children with specific outcomes. Further studies are needed to determine combinations of variables that may improve phenotype designation with the goal of improving asthma prevention and treatment as well as predicting outcomes and understanding the pathogenesis of asthma.

Hypertonic saline and acute wheezing in preschool children

BACKGROUND

Most acute wheezing episodes in preschool children are associated with rhinovirus. Rhinovirus decreases extracellular adenosine triphosphate levels, leading to airway surface liquid dehydration. This, along with submucosal edema, mucus plaques, and inflammation, causes failure of mucus clearance. These preschool children do not respond well to available treatments, even oral steroids. This calls for pro-mucus clearance and prohydration treatments such as hypertonic saline in wheezing preschool children.

METHODS

Randomized, controlled, double-blind study. Forty-one children (mean age 31.9 ± 17.4 months, range 1-6 years) presented with wheezing to the emergency department were randomized after 1 albuterol inhalation to receive either 4 mL of hypertonic saline 5% (HS) (n = 16) or 4 mL of normal saline (NS) (n = 25), both with 0.5 mL albuterol, twice every 20 minutes in the emergency department and 4 times a day thereafter if hospitalized. The primary outcome measured was length of stay (LOS) and the secondary outcomes were admission rate (AR) and clinical severity score.

RESULTS

The LOS was significantly shorter in the HS than in the NS group: median 2 days (range 0-6) versus 3 days (range 0-5) days (P = .027). The AR was significantly lower in the HS than the NS group: 62.2% versus 92%. Clinical severity score improved significantly in both groups but did not reach significance between them.

CONCLUSIONS

Using HS inhalations significantly shortens LOS and lowers AR in preschool children presenting with an acute wheezing episode to the emergency department.

Salmeterol and fluticasone in young children with multiple-trigger wheeze

BACKGROUND

Treatment guidelines recommend using an inhaled corticosteroid (ICS) plus a long-acting β(2)-agonist (LABA) for childhood asthma when the symptoms are not controlled by ICS alone, but the appropriate use of LABAs in children continues to be debated.

OBJECTIVE

To compare the efficacy of an inhaled salmeterol and fluticasone propionate combination, 50/100 μg twice daily, with fluticasone propionate, 100 μg twice daily, or salmeterol, 50 μg twice daily, in children with multiple-trigger wheeze.

METHODS

A total of 105 children 4 to 7 years of age with multiple-trigger wheezing based on respiratory symptoms and bronchodilator responsiveness and/or exercise-induced bronchoconstriction without a viral cold were randomized to salmeterol-fluticasone, fluticasone propionate alone, or salmeterol alone via a metered-dose inhaler and a spacer device for 8 weeks. The primary efficacy outcome was exhaled nitric oxide level. Secondary outcomes were lung function measurements via impulse oscillometry, respiratory symptoms, and rescue medication use.

RESULTS

The exhaled nitric oxide levels decreased after all treatments, significantly more so after salmeterol-fluticasone and fluticasone than with salmeterol (adjusted geometric means at 8 weeks: salmeterol-fluticasone, 9.4 ppb; fluticasone, 9.3 ppb; salmeterol, 13.9 ppb; salmeterol-fluticasone vs salmeterol, P = .02; fluticasone vs salmeterol, P = .01). No treatment differences were found with respect to respiratory symptoms or median rescue use. Salmeterol-fluticasone resulted in a small but statistically significant improvement in baseline lung function compared with fluticasone. All treatments were equally well tolerated.

CONCLUSION

The effects of salmeterol-fluticasone and fluticasone were comparable, although lung function improvement was better with salmeterol-fluticasone than with fluticasone alone. There is no obvious benefit in initiation therapy with salmeterol-fluticasone rather than fluticasone alone in the treatment of steroid-naive children with multiple-trigger wheeze.

TRIAL REGISTRATION

Pathway of clinical trial registry of Helsinki University:http://www.hus.fi/?Path=1;28;2530;9899;9900;23618;23903;33578.

Influence of host and environmental factors on wheezing severity in infants: findings from the PARIS birth cohort

BACKGROUND

Determinants of wheezing severity are poorly documented in infants.

OBJECTIVES

To study the determinants of wheezing severity in infants aged 18 months followed-up in the PARIS (« Pollution and Asthma Risk : an Infant Study ») birth cohort.

METHODS

Data on wheezing disorders, medical visits and medications, as well as biological markers of atopy, were collected during a medical examination at age 18 months. Severe wheeze was defined as wheeze that required inhaled corticosteroid and/or hospital-based care. Environmental exposures were assessed prospectively with regular questionnaires. Risk factors for wheeze in the first 18 months of life were assessed by multivariate regression models.

RESULTS

Participation in the medical examination concerned 48.2% of the original cohort. Prevalence of wheeze was 560/1879 (35.7%) and was influenced by male gender, parental history of asthma, siblings, daycare attendance, heavy parental smoking at home, and carpet covered floor in the child's bedroom. Being overweight increased the risk of wheeze by 62% (OR = 1.62, 95%CI 1.13-2.32). In addition, trends towards an increased risk of wheeze were found in infants exposed to daily use of cleaning sprays and to renovation activities. Conversely, the presence of a cat reduced the risk of wheeze (OR = 0.65, 95%CI 0.47-0.89), without any evidence of healthy-pet keeping effect. Severe wheeze concerned 286 of the wheezers (42.7%). The prevalence of severe wheeze was related to atopy, and risk of severe wheeze was in particular increased in infants having eosinophilia (OR = 1.76, 95%CI 1.21-2.55) or being sensitized to ≥ 2 allergens (OR = 1.88, 95%CI 1.13-3.14).

CONCLUSIONS AND CLINICAL RELEVANCE

Whilst risk factors for wheeze before 18 months of age are factors related to infections, indoor air pollution, and being overweight, the severity of wheeze is mainly due to the atopic status of the child. We suggest that atopy should be further considered in the assessment of wheezing severity in infants.

The effect of beclomethasone dipropionate in ultrafine particles on bronchial hyper-reactivity in young children

AIM

Bronchial hyper-reactivity (BHR) provides a tool for asthma diagnosis, assessment of severity and response to treatment. The effect of beclomethasone dipropionate in ultrafine particles (BDP-HFA) on BHR as measured by the adenosine challenge test in young children has not yet been determined. Our aim was to determine the effect of BDP-HFA (100 μg twice daily) on BHR as evaluated by a reduction of 20% from baseline FEV1 (PC20-FEV1) values in young asthmatic children.

METHODS

Twenty-one young children (13 males), mean age 4.95 ± 1.05 years, with partially controlled or controlled asthma completed a double-blind randomized, placebo-controlled, cross-over study. Each child received 4 weeks of treatment with either 100 μg BDP-HFA twice daily or placebo, and after a 2-week washout period the other way around. Primary outcomes were PC20-FEV1 concentration, and the stage number at which FEV1 values dropped by 20%.

RESULTS

Following 4 weeks of treatment, median PC20-FEV1 was 81.28 mg/mL while on BDP-HFA, compared with 9.64 mg/mL on placebo (p < 0.001). The median increase in stages required to achieve PC20 on BDP-HFA compared with placebo was three (95% CI 2.28-4.86).

CONCLUSION

Four weeks of treatment with BDP-HFA resulted in significantly decreased BHR in young children.

Common pediatric respiratory emergencies

Pediatric respiratory illnesses are a huge burden to emergency departments worldwide. This article reviews the latest evidence in the epidemiology, assessment, management, and disposition of children presenting to the emergency department with asthma, croup, bronchiolitis, and pneumonia.

Novel severe wheezy young children phenotypes: boys atopic multiple-trigger and girls nonatopic uncontrolled wheeze

BACKGROUND

Recurrent wheezing during infancy is a heterogeneous disorder that has been associated with early-onset asthma.

OBJECTIVE

To identify phenotypes of severe recurrent wheezing and therapeutic approaches.

METHODS

We performed cluster analysis with 20 variables of 551 children with active asthma, younger than 36 months old, and enrolled in the Trousseau Asthma Program.

RESULTS

We identified 3 independent clusters of children with wheezing. Cluster 1, mild episodic viral wheeze (n= 327), consisted of children with wheezing related only to colds (71%), mild disease (76%), and mainly normal chest x-ray results. Cluster 2, nonatopic uncontrolled wheeze (n = 157), was characterized by moderate to severe disease (91%), uncontrolled wheezing despite high doses of inhaled corticosteroids (55%), parents with asthma, and increased levels of ferritine. Cluster 3, atopic multiple-trigger wheeze (n = 67), included more children with multiple-trigger wheeze (68%) than did clusters 1 or 2; eczema (75%); a positive result from the Phadiatop Infant test (90%); increased levels of IgE, IgA, and IgG; and abnormal results from chest x-rays. In separate analysis, 1 parameter for boys (increased total level of IgE) and 2 parameters for girls (wheezing severity and increased total level of IgE) properly classified 90% of boys and 83% of girls in the appropriate cluster. Significant associations were found between overcrowding, molds and cockroaches at home, and atopic multiple-trigger wheeze and between day-care attendance and nonatopic uncontrolled wheeze in other parts.

CONCLUSION

We identified different phenotypes of recurrent wheezing in young children by using cluster analysis with usual variables. These phenotypes require confirmation in longer, follow-up studies.

The heterogeneity of asthma phenotypes in children and young adults

Objective. Genetic heterogeneity and risk factor distribution was analyzed in two previously proposed asthma phenotypes. Method. A sample of 412 subjects was investigated at 7-8, 12-13, and 21-22 years of age with questionnaires, skin prick tests, and genetic analysis of IL-4 receptor (IL4R) single-nucleotide polymorphisms. The sample was subdivided in one group with no asthma, and two groups with asthma separated by age of onset of symptoms, namely, early onset asthma (EOA) and late onset asthma (LOA). Risk factors and IL4R markers were analyzed in respect to asthma phenotypes. Results. EOA and LOA groups were both associated with atopy and a maternal history of asthma. Female gender was more common in LOA, whereas childhood eczema, frequent colds in infancy, and a paternal history of asthma were more common in EOA. The AA genotype of rs2057768 and the GG genotype of rs1805010 were more common in LOA, whereas the GG genotype of rs2107356 was less common in EOA. Conclusion. Our data suggest that early and late onset asthma may be of different endotypes and genotypes.

Interaction between asthma and lung function growth in early life

RATIONALE

The causal direction between asthma and lung function deficit is unknown, but important for the focus of preventive measures and research into the origins of asthma.

OBJECTIVES

To analyze the interaction between lung function development and asthma from birth to 7 years of age.

METHODS

The Copenhagen Prospective Studies on Asthma in Childhood is a prospective clinical study of a birth cohort of 411 at-risk children. Spirometry was completed in 403 (98%) neonates and again by age 7 in 317 children (77%).

MEASUREMENTS AND MAIN RESULTS

Neonatal spirometry and bronchial responsiveness to methacholine was measured during sedation by forced flow-volume measurements. Asthma was diagnosed prospectively from daily diary cards and clinic visits every 6 months. Children with asthma by age 7 (14%) already had a significant airflow deficit as neonates (forced expiratory flow at 50% of vital capacity second in neonates reduced by 0.34 z score by 1 mo; P = 0.03). This deficit progressed significantly during early childhood (forced expiratory flow at 0.5 seconds in neonates at age 7 reduced by 0.82 z score by age 7; P < 0.0001), suggesting that approximately 40% of the airflow deficit associated with asthma is present at birth, whereas 60% develops with clinical disease. Environmental tobacco exposure, but not allergic sensitization, also hampered airflow growth. Bronchial responsiveness to methacholine in the neonates was associated with the development of asthma (P = 0.01).

CONCLUSIONS

Children developing asthma by age 7 had a lung function deficit and increased bronchial responsiveness as neonates. This lung function deficit progressed to age 7. Therefore, research into the origins and prevention of asthma should consider early life before and after birth.

[The use of inhaled corticosteroids in preschool children]

Due to the large variation in symptoms presented, diagnosing wheezing or asthma and deciding on treatment for preschool children may be difficult. Inhaled corticosteroids may be effective for controlling asthma symptoms and recurrent wheezing also in this age group, but due to the heterogeneity of the disease and lack of diagnostic tools, both over- and under-treatment may occur. The author discusses current guidelines and recommendations for the use of inhaled corticosteroids in the preschool group. Inhaled corticosteroids are frequently prescribed in Norway for children in the first two years of life, whereas the guidelines recommend restrictive use of inhaled corticosteroids in this age group.

Corticosteroids in respiratory diseases in children

We review recent advances in the use of corticosteroids (CS) in pediatric lung disease. CS are frequently used, systemically or by inhalation. Their mechanisms of action in pulmonary diseases are ill defined. CS exert direct inhibitory effects on many inflammatory cells through genomic mechanisms. There is a time lag before clinical response, and the washout of effects is also prolonged. Prompt relief in some conditions, such as croup, may be related to airway mucosal vasoconstriction through a nongenomic mechanism. CS have proven beneficial roles in the treatment of asthma, croup, allergic bronchopulmonary aspergillosis, and subglottic hemangioma. In some conditions, such as bronchiolitis, cystic fibrosis, and bronchopulmonary dysplasia, their use is controversial and is not recommended routinely. In other conditions, such as tuberculosis, interstitial lung disease, acute lung aspiration, and acute respiratory distress syndrome, CS are often used empirically despite the lack of clear evidence of their benefit. New drug regimens, including the more flexible use of inhaled corticosteroids and long-acting β-agonists in asthma, the lack of efficacy of oral corticosteroids in preschool children with acute wheeze, the severe complications of systemic dexamethasone used to prevent bronchopulmonary dysplasia and thus more restricted use, and the beneficial effect of pulse high-dose intravenous methylprednisolone in patients with allergic bronchopulmonary aspergillosis or cystic fibrosis are among the major recent developments. There is concern about adverse effects, especially growth and adrenal suppression, induced by systemic CS in children. These have been reduced, but not eliminated, with the use of the inhaled route. The benefits must be weighed against the potential detrimental effects.

Characteristics of young atopic adults with self-reported past wheeze and airway hyperresponsiveness

BACKGROUND

The present study aimed to illustrate clinical characteristics of spirometric measures and allergy sensitisation among young atopic adults who reported wheezing episodes before adulthood but were not diagnosed with asthma by physicians and have no current wheeze symptoms (self-reported past-wheezers), especially those who exhibited airway hyperresponsiveness (AHR).

METHODS

Fifty self-reported past-wheezers were divided into two groups according to AHR to methacholine. Spirometric functions and blood atopic parameters were compared in these groups with those in 25 age-matched atopic adults with a history of childhood asthma diagnosed by specialists but have no current wheeze symptoms (past-asthmatics) and in 60 counterparts without a previous and current wheezing episode (never-wheezers).

RESULTS

Twenty-one of the 50 past-wheezers exhibited AHR (PC(20) < 8 mg/ml). Levels of spirometric function and allergic sensitization in both past-wheezer groups were intermediate between those in never-wheezers and past-asthmatics. Lower FEV(1) and FEF(25-75) values (% predicted) were observed in self-reported past-wheezers with AHR relative to those without AHR. More blood eosinophils and higher serum levels of total IgE and IgE specific to house dust mites were observed in self-reported past-wheezers with AHR relative to those without AHR.

CONCLUSIONS

Our findings raise the possibility that self-reported past-wheezers with AHR might form a distinct subgroup with features similar to past-asthmatics, which is one of the risk groups for adult asthma.

Phenotype-directed treatment of pre-school-aged children with recurrent wheeze

Wheeze in childhood may comprise different underlying diseases. Disease-specific treatment could potentially improve treatment efficacy. Various attempts have been made to differentiate between pre-school wheeze phenotypes. In this review, the results of clinical trials evaluating treatment of pre-school wheeze are discussed, with specific emphasis on the characteristics and phenotype of the study populations. Evidence suggests that systemic corticosteroids are not beneficial for the treatment of mild-to-moderate exacerbations of pre-school wheeze, irrespective of phenotype. The use of high-dose intermittent inhaled corticosteroid treatment cannot be recommended because of unacceptable side effects. Treatment with regular inhaled corticosteroids and leukotriene antagonists offer modest benefit, but neither treatment reduces hospitalisation rates. There is currently some evidence for a phenotype-specific effect of treatment. Phenotype-directed treatment of pre-school wheeze is currently limited by our ability to accurately differentiate between clinically useful phenotypes.

Elevated eosinophil protein X in urine from healthy neonates precedes development of atopy in the first 6 years of life

RATIONALE

Biomarkers predicting development of atopic disease are needed for targeted preventive measures and to study if disease pathology may be active before onset of symptoms.

OBJECTIVES

To investigate whether eosinophil protein X, leukotriene-C4/D4/E4, and 11β-prostaglandin (PG) F2α (PGD2 metabolite) assessed in urine from healthy at-risk neonates precede development of atopic disease during the first 6 years of life.

METHODS

We measured eosinophil protein X (n = 369), leukotriene-C4/D4/E4 (n = 367), and 11β-PGF2α (n = 366) in urine from 1-month-old children participating in the Copenhagen Prospective Studies on Asthma in Childhood birth cohort. Clinical data on development of allergic sensitization, allergic rhinitis, nasal eosinophilia, blood eosinophilia, eczema, troublesome lung symptoms (significant cough or wheeze or dyspnea), and asthma were collected prospectively until age 6 years. Associations between urinary biomarkers and development of atopic traits were investigated using general estimating equations, logistic regression, and Cox regression.

MEASUREMENTS AND MAIN RESULTS

Eosinophil protein X in the urine of the asymptomatic 1-month-old neonates was significantly associated with development of allergic sensitization (odds ratio, 1.49; 95% confidence interval [CI], 1.08–1.89), nasal eosinophilia (odds ratio, 3.2; 95% CI, 1.2–8.8), and eczema (hazard ratio, 1.4; 95% CI, 1.0–2.0), but not with allergic rhinitis, asthma, or blood eosinophilia. Neither leukotriene-C4/D4/E4 nor 11β-PGF2α was associated with any of the atopic phenotypes.

CONCLUSIONS

Eosinophil protein X in urine from asymptomatic neonates is a biomarker significantly associated with later development of allergic sensitization, nasal eosinophilia, and eczema during the first 6 years of life. These findings suggest activation of eosinophil granulocytes early in life before development of atopy-related symptoms.

Severe episodic viral wheeze in preschool children: High risk of asthma at age 5-10 years

In population studies, most children with episodic viral wheeze (EVW) become symptom free by 6 years. We studied the outcome of children with severe EVW, treated and followed up in hospital. We followed up 78 children <4 years, managed by paediatricians for severe EVW, to the age of 5-10 years. We recorded respiratory symptoms, spirometry and exhaled nitric oxide (FeNO). At follow-up, 42 children (54%) had current wheeze or dyspnoea, and 52 (67%) had current asthma. There was no significant difference between children with and without current asthma in FEV1 (p = 0.420), but FeNO was higher in children with current asthma (median (interquartile range) 14.5 (11.25-21.50) ppb) than in those without (12.0 (10.0-13.8) ppb, p = 0.020). Positive family history of asthma was the only factor associated with current asthma (odds ratio 8.77, 95% CI 2.88-26.69, p < 0.001). This remained significant after adjustment for duration of follow-up, gender and parental smoking. Conclusion. Severe EVW at preschool age has a high risk of asthma at age 5-10 years, and this is reinforced by a positive family history of asthma and to elevated FeNO levels.

Clinical effectiveness of inhaled corticosteroids versus montelukast in children with asthma: prescription patterns and patient adherence as key factors

OBJECTIVES

To examine the real-life effectiveness of inhaled corticosteroids (ICS) versus leukotriene receptor antagonists (LTRA) monotherapy in children with mild or moderate asthma.

METHODS

Using medical and drug records, we accrued a cohort of 227 children aged 2-17 years, prescribed daily LTRA or ICS monotherapy. LTRA-treated children were matched on age, gender, and previous acute-care visits in a 1:3 ratio to ICS-treated children. Outcomes included rescue oral corticosteroids, prescription duration and dispensing, acute-care visits, hospital admissions, and β(2)-agonist use.

RESULTS

More ICS- than montelukast-treated children had persistent asthma (73 vs. 50%) and fewer had good asthma control (35 vs. 61%) at baseline, suggesting residual confounding by indication. Physician prescriptions covered 62% of the follow-up period for ICS compared to 97% for montelukast (mean group difference [MGD]: -17%, 95% CI: -28%, -7%). In pharmacies, patients claimed 51 vs. 74% of prescribed ICS and montelukast, respectively (MGD = -12% [-20%, -4%]). Consequently, dispensed ICS and montelukast covered 24% and 38% of follow-up period, respectively (MGD = -14% [-22%, -6%]). No group differences in oral corticosteroids (RR = 1.10 [0.66, 1.84]) and acute-care visits (RR = 1.79 [0.96, 3.34]) were observed. ICS-treated children experienced more hospital admissions (RR = 3.63 [1.20, 11.03]) and needed more frequently rescue β(2)-agonist use of ≥4 doses per week (RR = 2.54 [1.23, 5.23]).

CONCLUSIONS

When compared to LTRA, the prescription of ICS monotherapy did not significantly reduce rescue oral corticosteroids or acute care visits and was associated with a higher rate of hospital admission for asthma and rescue β(2)-agonist use. The findings may be due to paradoxical shorter ICS prescription duration and lower patient adherence, despite more persistent asthma and poorer control than in LTRA-treated children.

Therapy for cough: where does it fall short?

Studies on cough have come a long way but many shortfalls still exist. These shortfalls can be attributed to: the lack of randomized controlled studies with a focus on cough; studies not using robust cough outcome measures, poor definition of target groups in studies and guidelines, the lack of safe and efficacious treatments; difficulty in defining etiological factors, and the lack of data on the predictors of response to therapies for cough dominant etiologies. Addressing shortfalls in cough therapy that focuses on improving the lives of people with cough requires a systematic approach that includes better medications, high quality studies, improved multidisciplinary guidelines and education (of both health professionals and patients). To achieve new cough therapeutics requires an improved understanding of cough in humans (i.e., not just in animals). Development of new medications without substantial adverse events is long awaited for cough.

New insights into the natural history of asthma: primary prevention on the horizon

Recent studies of the natural history of asthma have shifted attention toward viral respiratory tract illness in early life as a major risk factor associated with the development of the most persistent forms of the disease. Although early aeroallergen sensitization is strongly associated with chronic asthma, several trials in which single-aeroallergen exposure in pregnancy and early childhood was successfully accomplished and compared with sham avoidance have failed to show any decrease in asthma incidence. New evidence suggests that complex interactions occur between viral infection and aeroallergen sensitization in genetically susceptible subjects that trigger the immune responses and airway changes that are characteristic of persistent asthma. The finding that exposure to bacterial products among children raised on farms is associated with diminished asthma prevalence during the school years has now been replicated, and experimental studies have suggested that these effects are mediated by the activation of regulatory T cells in the airway. It is thus plausible to hypothesize that primary prevention of asthma could be attained through surrogate therapeutic interventions that activate similar mechanisms in young children at high risk for asthma.

The multiple meanings of "wheezing": a questionnaire survey in Portuguese for parents and health professionals

Background

Most epidemiological studies on pediatric asthma rely on the report of "wheezing" in questionnaires. Our aim was to investigate the understanding of this term by parents and health professionals.

Methods

A cross-sectional survey was carried out in hospital and community settings within the south of Portugal. Parents or caregivers self-completed a written questionnaire with information on social characteristics and respiratory history. Multiple choice questions assessed their understanding of "wheezing". Health professionals (physicians, nurses and physiotherapists) were given an adapted version. We used bivariate analysis and multivariate models to study associations between definitions of "wheezing" and participants' characteristics.

Results

Questionnaires from 425 parents and 299 health professionals were included. The term "wheezing" was not recognized by 34% of parents, more frequently those who were younger (OR 0.4 per 10-year increment, 95% CI 0.3-0.7), had lower education (OR 3.3, 95% CI 1.5-7.4), and whose children had no history of respiratory disease (OR 4.6, 95% CI 2.5-8.7) (all ORs adjusted). 31% of parents familiar with "wheezing" either did not identify it as a sound, or did not locate it to the chest, while tactile (40%) and visual (34%) cues to identify "wheezing" were frequently used. Nurses reported using visual stimuli and overall assessments more often than physicians (p < 0.01). The geographical location was independently associated with how parents recognized and described "wheezing".

Conclusions

Different meanings for "wheezing" are recognized in Portuguese language and may be influenced by education, respiratory history and regional terminology. These findings are likely applicable to other non-English languages, and suggest the need for more accurate questionnaires and additional objective measurement instruments to study the epidemiology of wheezing disorders.