Infection-induced wheezing in young children

Environmental exposures associated with early childhood recurrent wheezing in the mother and child in the environment birth cohort: a time-to-event study

BACKGROUND

Antenatal factors and environmental exposures contribute to recurrent wheezing in early childhood.

AIM

To identify antenatal and environmental factors associated with recurrent wheezing in children from birth to 48 months in the mother and child in the environment cohort, using time-to-event analysis.

METHOD

Maternal interviews were administered during pregnancy and postnatally and children were followed up from birth to 48 months (May 2013-October 2019). Hybrid land-use regression and dispersion modelling described residential antenatal exposure to nitrogen dioxide (NO2) and particulate matter of 2.5 µm diameter (PM2.5). Wheezing status was assessed by a clinician. The Kaplan-Meier hazard function and Cox-proportional hazard models provided estimates of risk, adjusting for exposure to environmental tobacco smoke (ETS), maternal smoking, biomass fuel use and indoor environmental factors.

RESULTS

Among 520 mother-child pairs, 85 (16%) children, had a single wheeze episode and 57 (11%) had recurrent wheeze. Time to recurrent wheeze (42.9 months) and single wheeze (37.8 months) among children exposed to biomass cooking fuels was significantly shorter compared with children with mothers using electricity (45.9 and 38.9 months, respectively (p=0.03)). Children with mothers exposed to antenatal ETS were 3.8 times more likely to have had recurrent wheeze compared with those not exposed (adjusted HR 3.8, 95% CI 1.3 to 10.7). Mean birth month NO2 was significantly higher among the recurrent wheeze category compared with those without wheeze. NO2 and PM2.5 were associated with a 2%-4% adjusted increased wheezing risk.

CONCLUSION

Control of exposure to ETS and biomass fuels in the antenatal period is likely to delay the onset of recurrent wheeze in children from birth to 48 months.

The Use of Bacterial Lysate for the Prevention of Wheezing Episodes in Preschool Children: A Cost-Utility Analysis

BACKGROUND

Although increasing recent evidence has shown the efficacy of bacterial lysate therapy for the prevention of wheezing episodes and asthma exacerbations in pediatric patients, evidence of its cost-effectiveness in preschool patients is scarce.

OBJECTIVES

To evaluate the cost-utility of bacterial lysate therapy as an add-on to standard care of preschool children with recurrent wheezing.

METHODS

To achieve the objectives of the study, we used a Markov simulation model with 3 mutually exclusive nonabsorbent states (regular Markov chain). Effectiveness parameters were obtained from a recent systematic review of the literature with meta-analyses (5 randomized controlled trials, 433 children). Cost data were obtained from hospital bills and from the national manual of drug prices in Colombia. The study was carried out from the perspective of the national health care system in Colombia. The main outcome of the model was quality-adjusted life-years. To assess the robustness of the model's results, we performed deterministic and probabilistic sensitivity analysis.

RESULTS

Compared with standard care, bacterial lysate add-on therapy to standard care was associated with lower overall treatment costs (US $694.03 vs $830.71 average cost per patient) and the greatest gain in QALYs (0.9211 vs 0.9154 QALYs on average per patient), thus showing dominance.

CONCLUSIONS

In Colombia, compared with standard care, bacterial lysate add-on therapy to standard care for treating preschool children with recurrent wheezing is a dominant strategy because it showed a greater gain in QALYs at lower total treatment costs.

Pathogens and Pathogenesis in Wheezing Diseases in Children Under 6

Few studies have comprehensively assessed the roles of cytokine production in wheezing pathogenesis. Therefore, we undertook this study to determine the association between wheezing episodes and cytokines, and to provide further information on this topic. Firstly, we retrospectively collected I176 children, including 122 subjects with first wheezing and 54 subjects with recurrent wheezing, to analyze the etiology and clinical characteristics of children with wheezing diseases. Then, we collected 52 children with wheezing diseases and 25 normal controls to detect the expression of interferon-γ (IFN-γ), interleukin-4 (IL-4), IFN-γ/IL-4, IL-17A, IL-17E, IgE, matrix metalloproteinase-3 (MMP-3), and MMP-9 in serum or plasma. The results showed that boys under 3 years old with history of allergies were more likely to develop wheezing diseases. In our cohort, M. pneumoniae caused a greater proportion of wheezing in children than expected. The expression of IgE [18.80 (13.65-31.00) vs. 17.9 (10.15-21.60)], IL-4 [24.00 (24.00-48.00) vs. 23.00 (9.50-27.00)], IFN-γ [70.59 (41.63-116.46) vs. 49.83 (29.58-81.74)], MMP3 [53.40 (20.02-128.2) vs. 30.90 (13.80-50.95)], MMP9 [148.10 (99.30-276.10) vs. 122.10 (82.20-162.35)], IL-17A [80.55 (54.46-113.08) vs. 61.11 (29.43-93.87)], and IL-17E [1.75 (0.66-2.77) vs. 1.19 (0.488-2.1615)] were significantly increased in the wheezing group (p<0.05) compared to normal controls, while the level of IFN-γ/IL-4 had no significant difference between the two groups (1.24 ± 1.88 vs 0.68 ± 0.74, p>0.05). There was altered cytokine production in children with wheezing diseases which was quite similar to asthma pathogenesis. Sex, age, pathogen infection, and inflammation in our study were also risk factors for wheezing diseases.

Prevention and treatment of recurrent viral-induced wheezing in the preschool child

OBJECTIVE

To summarize the recent evidence in the treatment of viral-induced wheezing in the infant and preschool aged child.

DATA SOURCES

Published literature obtained through PubMed database searches.

STUDY SELECTIONS

Studies relevant to phenotypes and treatment of wheezing illnesses in infants and preschool children were included.

RESULTS

Recurrent wheezing in preschool children is common and is frequently triggered by viral respiratory tract infections. Certain phenotypes may respond to treatments differently, depending on the risk factors identified. Inhaled corticosteroids, administered continuously or intermittently, reduce the risk of virus-induced wheezing episodes. The use of leukotriene modifying agents may have a role in wheezing episodes in a select group of preschool children. Early administration of azithromycin reduces the risk of severe lower respiratory tract illnesses in children. The effect of oral corticosteroids on wheezing episodes in young children varies by degree of episode severity.

CONCLUSION

Recurrent viral-induced wheezing illnesses has been the focus of many clinical trials, which now provide an increasingly robust evidence base for management. Additional research is needed to define optimal strategies, to best match therapies to specific phenotypes and endotypes, and will eventually begin to include therapies directed specifically at the viral triggers.

Perinatal maternal mental health is associated with both infections and wheezing in early childhood

BACKGROUND

Wheezing and infections are common during infancy, and the role of early-life exposures in their development is still under investigation. We examined associations between maternal mental health in pregnancy and after delivery and subsequent offspring wheezing and infections.

METHODS

We studied 2314 mother-child pairs recruited in the Piccolipiù birth cohort (Italy) from 2011 to 2015. Maternal mental health was assessed in pregnancy and 12 months after delivery via the General Health Questionnaire-12 (GHQ-12). GHQ-12 Likert scores were collapsed into low (below the upper tercile) and high (above). Risk ratios (RR) and 95% confidence intervals (CI) between each combination of scores-during pregnancy and 1 year after delivery-and outcomes were computed by log-binomial regression models.

RESULTS

High scores both in pregnancy and after delivery, compared with low scores in both periods, were associated with wheezing (RR: 1.35; 95% CI: 1.08, 1.69), recurrent (≥2 episodes) wheezing (1.35; 0.99, 1.83), any and recurrent (≥4 episodes) upper respiratory infections (1.20; 1.04, 1.41, and 1.45; 1.07, 1.97, respectively), lower respiratory infections (1.31; 1.08, 1.61), and diarrhea (1.49; 1.23, 1.80). High scores either during pregnancy or 1 year after delivery only were less consistently associated with outcomes.

CONCLUSIONS

Maternal mental health problems extending from pregnancy to the first year after delivery are associated with development of both wheezing and infections. As wheezing is mostly triggered by infections, increased infection susceptibility could represent a possible common biologic mechanism. This study confirms the importance of early-life exposures on childhood health.

Efficacy of treatment with montelukast, fluticasone propionate and budesonide liquid suspension for the prevention of recurrent asthma paroxysms in children with wheezing disorders

One-third of the children who suffer from first-time wheezing are estimated to experience recurrences; however, no standard therapeutic strategy with which to prevent these recurrences currently exists. A few studies have compared the three drugs commonly used for the treatment of persistent asthma in children to identify the most effective one for preventing recurrent wheezing. In this study, in an aim to determine the most effective of these drugs, we recruited patients <5 years of age with recurrent wheezing at our hospital, and assigned them randomly to either the oral montelukast [leukotriene receptor antagonist (LTRA)], the inhaled fluticasone propionate (FP), or the inhaled budesonide suspension (BUD) groups for 12-week treatments. We then determined the treatment efficacy (symptomatic improvement) by recording the number of wheezing episodes and emergency visits, the daily treatment cost, the mean accumulated down time and the patient compliance; we then compared the results among the groups. All treatments were found to be equally effective. The daily cost of inhaled FP was lower than that of oral LTRA and inhaled BUD (P<0.00001). The difference in the mean accumulated down time between these groups was not significant (P=0.132). The adherence (patient compliance) to LTRA was significantly higher than the adherence to inhaled corticosteroids (ICS) (P<0.017). On the whole, the findings of this study indicated that all three treatments prevented recurrent wheezing in our pediatric population. FP was found to be more convenient, to require fewer doses, and that it could be easily adjusted. Patient adherence/compliance to treatment was significantly better with LTRA than with ICS.

Associations between maternal mental health and early child wheezing in a South African birth cohort

BACKGROUND

Wheezing in early childhood is common and has been identified in high-income countries (HIC) as associated with maternal antenatal or postnatal psychosocial risk factors. However, the association between maternal mental health and childhood wheezing has not been well studied in low and middle-income countries (LMIC), such as South Africa.

METHODS

A total of 1137 pregnant women over 18 year old, between 20 and 28 weeks' gestation, and attending either of two catchment area clinics were enrolled in a South African parent study, the Drakenstein Child Health Study (DCHS). Psychosocial risk factors including maternal depression, psychological distress, early adversity, and intimate partner violence (IPV), were measured antenatally and postnatally by validated questionnaires. Two outcomes were evaluated: Presence of wheeze (at least one episode of child wheeze during the first 2 years of life); and recurrent wheeze (two or more episodes of wheezing in a 12-month period). Logistic regression was used to investigate the association between antenatal or postnatal psychosocial risk factors and child wheeze, adjusting for clinical and socio-demographic covariates.

RESULTS

Postnatal psychological distress and IPV were associated with both presence of wheeze (adjusted OR = 2.09, 95%CI: 1.16-3.77 and 1.63, 95%CI: 1.13-2.34, respectively), and recurrent child wheeze (adjusted OR = 2.26, 95%CI: 1.06-4.81 and 2.20, 95%CI: 1.35-3.61, respectively).

CONCLUSION

Maternal postnatal psychological distress and IPV were associated with wheezing in early childhood. Thus, screening and treatment programs to address maternal psychosocial risk factors may be potential strategies to reduce the burden of childhood wheeze in LMICs.

Management of preschool recurrent wheezing and asthma: a phenotype-based approach

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent evidence on the management of preschool children with wheezing and asthma, and to propose a phenotype-based approach to the management of these children.

RECENT FINDINGS

Recent studies have begun to identify populations of preschool children that are likely to benefit from inhaled corticosteroids (ICS) therapy and defined ICS regimens: daily ICS in preschool children with persistent asthma, and pre-emptive high-dose intermittent ICS among preschool children with intermittent disease reduce the risk of exacerbation. In addition, among preschool children with mild persistent asthma, the presence of aeroallergen sensitivity and/or blood eosinophil counts of 300/μL or greater are predictors of good response to daily ICS therapy. Other studies identified intermittent azithromycin as a therapy to prevent, and potentially to treat, acute exacerbations.The uncertainty of the role of oral corticosteroids (OCS) as a therapy for acute exacerbations continues, as a recent meta-analysis showed that OCS did not prevent hospitalizations or urgent visits, and did not reduce the need for additional courses of OCS. Whereas previous epidemiologic studies suggested acetaminophen may increase risk of exacerbations, a clinical trial clearly demonstrated acetaminophen use, compared to ibuprofen use,does not increase exacerbation risk among preschool children with mild-persistent asthma.

SUMMARY

Recent studies have shown potential for phenotypic-driven therapies for the management of preschool children with asthma. Targeting airway bacteria has emerged as a promising therapeutic approach, but its effect on antibiotic resistance still needs to be investigated. Finally, more studies are required to evaluate if oral corticosteroids provide any benefits for acute episodic wheeze.

Leukotriene receptor antagonists as maintenance and intermittent therapy for episodic viral wheeze in children

BACKGROUND

Episodic viral wheeze (EVW) associated with viral respiratory tract infections is a common reason for pre-school children to utilise health care resources and for carers to take time away from employment. About a third of children experience a wheezing episode before the age of five years. EVW therefore represents a significant public health problem. Many pre-school children only wheeze in association with viral infections and in such cases EVW appears to be a separate entity from atopic asthma. Some trials have explored the effectiveness of leukotriene receptor antagonists (LTRAs) as regular (maintenance) or episodic (intermittent) treatment in this context.

OBJECTIVES

To evaluate the evidence for the efficacy and safety of maintenance and intermittent LTRAs in the management of EVW in children aged one to six years.

SEARCH METHODS

We searched the Cochrane Airways Group register of trials with pre-specified terms. We performed additional searches by consulting the authors of identified trials, online trial registries of manufacturers' web sites, and reference lists of identified primary papers and reviews. Search results are current to June 2015.

SELECTION CRITERIA

We included randomised controlled trials with a parallel-group or cross-over (for intermittent LTRA only) design. Maintenance was considered as treatment for more than two months and intermittent as less than 14 days. EVW was defined as a history of at least one previous episode of wheezing in association with a viral respiratory tract infection in the absence of symptoms between episodes. As far as possible, relevant specific data were obtained from authors of studies that included children of a wider age group or phenotype.  

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion in the review and assessed risk of bias. The primary outcome was number of children with one or more viral-induced episodes requiring one or more treatments with rescue oral corticosteroids. We analysed combined continuous data outcomes with the mean difference and dichotomous data outcomes with an odds ratio (OR).

MAIN RESULTS

We identified five studies eligible for inclusion in the review (one investigated maintenance treatment, three intermittent therapy and one had both maintenance and intermittent treatment arms) these included 3741 participants. Each study involved oral montelukast and was of good methodological quality, but differed in choice of outcome measures thus limiting our ability to aggregate data across studies. Only primary outcome and adverse event data are reported in this abstract.For maintenance treatment, specific data obtained from a single study, pertaining to children with only an EVW phenotype, showed no statistically significant group reduction in the number of episodes requiring rescue oral corticosteroids associated with daily montelukast versus placebo (OR 1.20, 95% CI 0.70 to 2.06, moderate quality evidence).For intermittent LTRA, pooled data showed no statistically significant reduction in the number of episodes requiring rescue oral steroids in children treated with LTRA versus placebo (OR 0.77, 95% CI 0.48 to 1.25, moderate quality evidence). Specific data for children with an EVW phenotype obtained from a single study of intermittent montelukast treatment showed a small, but statistically significant reduction in unscheduled medical attendances due to wheeze (RR 0.83, 95% CI 0.71 to 0.98).For maintenance compared to intermittent LTRA treatment no data relating to the primary outcome of the review were identified.There were no other significant group differences identified in other secondary efficacy outcomes for maintenance or intermittent LTRA treatment versus placebo, or maintenance versus intermittent LTRA treatment. We collected descriptive data on adverse events as reported by four of the five included studies, and rates were similar between treatment and placebo groups.Potential heterogeneity in the phenotype of participants within and across trials is a limitation of the evidence.

AUTHORS' CONCLUSIONS

In pre-school children with EVW, there is no evidence of benefit associated with maintenance or intermittent LTRA treatment, compared to placebo, for reducing the number of children with one or more viral-induced episodes requiring rescue oral corticosteroids, and little evidence of significant clinical benefit for other secondary outcomes. Therefore until further data are available, LTRA should be used with caution in individual children. When used, we suggest a therapeutic trial is undertaken, during which efficacy should be carefully monitored. It is likely that children with an apparent EVW phenotype are not a homogeneous group and that subgroups may respond to LTRA treatment depending on the exact patho-physiological mechanisms involved.

Update on the utility of corticosteroids in acute pediatric respiratory disorders

BACKGROUND

Corticosteroids, delivered systemically and by inhalation, are widely used for the treatment of multiple acute respiratory illnesses in children. However, the level of evidence to support the utility of this therapy varies between these different acute respiratory illnesses.

OBJECTIVE

To summarize the evidence regarding the utility of corticosteroids in the management of common acute pediatric respiratory conditions and to highlights the controversies regarding their use.

METHODS

Literature search of manuscripts describing the evidence regarding the efficacy of corticosteroids (systemic and inhaled) in the management of: acute asthma exacerbation among school age children, acute episodic wheeze among preschool children, viral croup, and acute viral bronchiolitis.

RESULTS

Current evidence indicates that systemic corticosteroids provide benefits for the treatment of acute asthma exacerbations in school age children, mainly in the acute care setting. In addition, high dose inhaled corticosteroid therapy administered in the Emergency Department appears to have comparable effect for the prevention of asthma-related hospital admission as systemic corticosteroids in this age group. In contrast, most available studies have not shown benefit for systemic corticosteroids during acute wheezing episodes in preschool children. Systemic corticosteroids decrease symptoms and the rate of hospital admissions in patients with severe croup; however, corticosteroids have no role in the treatment of acute bronchiolitis and their use in this condition should be discouraged.

CONCLUSION

Corticosteroids treatment response varies between the acute respiratory illnesses presented in this review. Future research should aim to fill the current gaps-of-knowledge regarding the utility this intervention such as the identification of specific wheezing phenotypes among preschool children which might benefit from systemic corticosteroids as a treatment for acute viral wheeze.

An update on the efficacy of oral corticosteroids in the treatment of wheezing episodes in preschool children

Traditionally, oral corticosteroids (OCSs) have been the mainstay of treatment for acute wheezing episodes among preschool children with a history of recurrent wheezing. Although there is substantial evidence for the efficacy of OCSs as a treatment for asthma exacerbations in school-aged children and adolescents, recent clinical studies questioned the benefits of OCSs as a treatment for acute wheezing in preschool children. This review summarizes the current evidence on the efficacy of OCSs as a treatment for acute wheezing episodes among preschool age children with episodic wheezing, focusing on studies performed in three different settings: OCS treatment initiated by parents in the outpatient setting, OCS treatment initiated in the emergency department (ED), and OCS treatment among hospitalized preschool children. The results of most studies reviewed in this paper do not support the efficacy of OCS treatment among preschool children with recurrent wheezing. The heterogeneity of early childhood wheezing and asthma might be part of the explanation for lack of efficacy of this intervention noted in multiple studies.