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

Update in paediatric asthma

PURPOSE OF REVIEW

The field of paediatric asthma is rapidly moving, with the advent of new biologicals for severe asthma and increased understanding of preschool wheeze amongst other developments and insights.

RECENT FINDINGS

There is increasing evidence of efficacy in children for biologics directed against Type 2 inflammation (especially mepolizumab and dupilumab) as well encouraging evidence that Tezepelumab may be effective against Type 2 low phenotypes. The importance of airway remodelling and infection in the pathophysiology of preschool wheeze is increasingly appreciated. The treatment of preschool wheeze is moving from symptom-based to biomarker driven therapies. Other important areas are prediction of risk of asthma attacks, the SMART regime, the importance of climate change and reducing greenhouse gas emissions from inhalers while ensuring adequate therapy for young children, the association of early adverse environmental factors including childhood poverty and deprivation and the switch to race-neutral lung function equations.

SUMMARY

We are increasingly moving towards personalized medicine and the use of biomarkers to guide treatment of wheeze at all ages, but we need to move from counting cells to determining their functional status. Airway wall structural changes rather than inflammation may drive the progression of preschool wheeze to school age asthma.

Epidemiology of asthma across the ages

In the past 3 decades, the overall prevalence of asthma appears to be plateauing, although large geographic and socioeconomic variation is evident. Overall, asthma prevalence slightly decreased in most age groups, except for school-aged children. Of note, asthma mortality steadily decreased, potentially highlighting improved asthma management strategies. Several epidemiologic studies indicate that a complex interplay between genetic, environmental, and immunologic factors predisposes individuals to asthma inception and persistence across different life stages. Established risk factors for preschool wheezing to asthma persistence comprise a combination of pre- and post-natal parameters including the maternal history of asthma, prematurity, caesarian section, early-life respiratory infections, exposure to air pollution or tobacco smoke, and allergic polysensitization. On the other hand, persistence into adulthood is mainly driven by disease severity, allergic multimorbidity, relevant comorbidities, severe respiratory infections, and tobacco smoke exposure. It is evident that asthma prevention strategies do not fit a "one size fits all" concept and key environmental interventions should be tailored to different regions of the world. Undoubtedly, the heterogeneity of asthma as a disease is at least partly reflected in the reported epidemiologic measures, and continuing, methodologically rigorous studies will allow us to unravel some of the observed discrepancies.

Population Attributable Risk of Wheeze in 2-<6-Year-old Children, Following a Respiratory Syncytial Virus Lower Respiratory Tract Infection in The First 2 Years of Life

BACKGROUND

There is limited evidence regarding the proportion of wheeze in young children attributable to respiratory syncytial virus lower respiratory tract infections (RSV-LRTI) occurring early in life. This cohort study prospectively determined the population attributable risk (PAR) and risk percent (PAR%) of wheeze in 2-<6-year-old children previously surveilled in a primary study for RSV-LRTI from birth to their second birthday (RSV-LRTI<2Y).

METHODS

From 2013 to 2021, 2-year-old children from 8 countries were enrolled in this extension study (NCT01995175) and were followed through quarterly surveillance contacts until their sixth birthday for the occurrence of parent-reported wheeze, medically-attended wheeze or recurrent wheeze episodes (≥4 episodes/year). PAR% was calculated as PAR divided by the cumulative incidence of wheeze in all participants.

RESULTS

Of 1395 children included in the analyses, 126 had documented RSV-LRTI<2Y. Cumulative incidences were higher for reported (38.1% vs. 13.6%), medically-attended (30.2% vs. 11.8%) and recurrent wheeze outcomes (4.0% vs. 0.6%) in participants with RSV-LRTI<2Y than those without RSV-LRTI<2Y. The PARs for all episodes of reported, medically-attended and recurrent wheeze were 22.2, 16.6 and 3.1 per 1000 children, corresponding to PAR% of 14.1%, 12.3% and 35.9%. In univariate analyses, all 3 wheeze outcomes were strongly associated with RSV-LRTI<2Y (all global P < 0.01). Multivariable modeling for medically-attended wheeze showed a strong association with RSV-LRTI after adjustment for covariates (global P < 0.0001).

CONCLUSIONS

A substantial amount of wheeze from the second to sixth birthday is potentially attributable to RSV-LRTI<2Y. Prevention of RSV-LRTI<2Y could potentially reduce wheezing episodes in 2-<6-year-old children.

Exposure to climate change-related extreme events in the first year of life and occurrence of infant wheezing

INTRODUCTION

Climate change increases the intensity and frequency of extreme events, which will most impact younger generations. Within the NINFEA birth cohort, we investigated the relationship between exposure to such events during the first year of life and infant respiratory health.

METHODS

The NINFEA cohort study recruited pregnant women across 11 years in Italy, allowing for climatic variability exploitation by birth place and time. We combined geocoded addresses with climate data, to derive children's cumulative exposure to the following extreme events during their first year: (i) heatwaves (i.e. 3 + consecutive days, with maximum temperature > 35 °C); (ii) days with wildfire PM2.5 >15 μg/m3 and (iii) daily precipitation > 100 mm; (iv) months with exceptional drought. Logistic regression models estimated the relationship between each exposure and wheezing at 6-18 months, adjusting for individual and contextual factors.

RESULTS

Wheezing prevalence in the cohort was 17.6%. The exposure to each additional heatwave in the first year of life increased wheezing risk by 16%, with an odds ratio (OR) of 1.16 and a 95% Confidence Interval (CI) of 1.00;1.35. The OR for each month of extreme drought exposure was 1.10, 95%CI 0.95; 1.26. Results for wildfire PM2.5 were unclear with wider confidence intervals (OR for each high exposure day:1.36, 95% CI 0.85; 2.16). Wheezing was not associated with extreme precipitation.

CONCLUSIONS

Exposure to multiple extreme events, especially heatwaves, in the first year of life is associated with later infant respiratory health suggesting the need to implement climate change mitigation policies to protect long-term health.

Salbutamol safety in children under 2 years of age with acute wheezing: a meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the safety of short-term use of inhaled salbutamol in children under 2 years of age with acute wheezing.

DATA SOURCES

Electronic databases (PubMed, Trip, MEDLINE) and the Cochrane Library were searched for studies published up to October 2022.

STUDY SELECTION

The search was restricted to randomised controlled trials published in English regarding the safety of inhaled salbutamol in wheezing children under the age of 2.

DATA EXTRACTION AND SYNTHESIS

The literature search strategy yielded 3532 references. The meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

MAIN OUTCOMES AND MEASURES

The incidence of adverse reactions associated with inhaled salbutamol administration compared with placebo.

RESULTS

A total of 24 records were included. In 7 studies involving 597 patients, inhaled salbutamol was compared with controls and no statistically significant difference in the incidence of adverse drug reactions was found between the two groups (OR 2.12, 95% CI 0.69 to 6.51; p=0.19). Salbutamol administration via nebulisation was associated with an increased incidence of adverse reactions (OR 6.76, 95% CI 2.01 to 22.71; p=0.002). None of the studies reported severe cardiac side effects that necessitated withdrawal from the study following salbutamol administration. Only one study reported a significant non-cardiac side effect (severe tremulousness) that necessitated withdrawal from therapy.

CONCLUSIONS

Inhaled salbutamol can be safely used in children under 2 years of age with acute wheeze with the administration via a metered-dose inhaler being potentially safer than a nebulised formulation. Neither of the formulations was associated with severe adverse effects.

Mechanistic modelling of allergen-induced airways disease in early life

Asthma affects approximately 300 million individuals worldwide and the onset predominantly arises in childhood. Children are exposed to multiple environmental irritants, such as viruses and allergens, that are common triggers for asthma onset, whilst their immune systems are developing in early life. Understanding the impact of allergen exposures on the developing immune system and resulting alterations in lung function in early life will help prevent the onset and progression of allergic asthma in children. In this study, we developed an in silico model describing the pulmonary immune response to a common allergen, house dust mite, to investigate its downstream impact on the pathophysiology of asthma, including airway eosinophilic inflammation, remodelling, and lung function. We hypothesised that altered epithelial function following allergen exposure determines the onset of airway remodelling and abnormal lung function, which are irreversible with current asthma therapies. We calibrated the in silico model using age appropriate in vivo data from neonatal and adult mice. We validated the in silico model using in vivo data from mice on the effects of current treatment strategies. The in silico model recapitulates experimental observations and provides an interpretable in silico tool to assess airway pathology and the underlying immune responses upon allergen exposure. The in silico model simulations predict the extent of bronchial epithelial barrier damage observed when allergen sensitisation occurs and demonstrate that epithelial barrier damage and impaired immune maturation are critical determinants of reduced lung function and asthma development. The in silico model demonstrates that both epithelial barrier repair and immune maturation are potential targets for therapeutic intervention to achieve successful asthma prevention.

Daycare use of disinfectants and cleaning products and wheeze among children: Cross-sectional analyses in the French CRESPI cohort

BACKGROUND

Evidence is mounting that domestic use of disinfectants and cleaning products (DCP), particularly in spray form, is associated with wheezing in children. Beyond the home environment, many children are also exposed to DCP in daycare. The links between daycare exposures to DCP and child respiratory health have never before been studied.

OBJECTIVES

Evaluate the associations between daycare DCP use and wheeze among children.

METHODS

This cross-sectional study draws upon the data at inclusion for 536 children (mean age: 22.3 months; 47.4 % female) of the French CRESPI cohort (108 daycares in the Paris region, 2019-2022). Exposure to DCP was evaluated using a barcode-scanning smartphone application with an embedded questionnaire. An exposure score was calculated as the sum of frequencies of use of DCP for each daycare. Child wheezing outcomes (ever wheeze since birth, recurrent wheeze (≥3 times since birth), and wheeze ever treated with inhaled corticosteroids (ICS)) were evaluated by parental questionnaire. Associations between daycare DCP exposure and wheezing outcomes were analyzed with Generalized Estimating Equations to account for a possible center effect, and adjusted for child age, parental smoking status, parental educational attainment, and daycare size.

RESULTS

The prevalence of ever wheeze was 32.1 %, that of recurrent wheeze 13.3 %, and that of wheeze ever treated with ICS 14.5 %. Above-median exposure scores (vs. ≤ median exposure scores) were associated with higher odds of wheeze ever treated with ICS (Odds Ratio = 1.72, 95 % Confidence Interval: 1.07-2.75) and ever wheeze (1.40, 0.98-2.00), but not with recurrent wheeze (1.35, 0.79-2.31). Relationships between specific DCP application modes and wheezing outcomes did not suggest a predominant role of specific modes.

DISCUSSION

Given the observed association between daycare DCP use and wheeze in children, measures which limit child exposure to DCP in care settings should be considered.

Objective detection of wheeze at home by parents through a digital device: usage patterns and relationship with SABA administration

INTRODUCTION

Wheezing is an important indicator of exacerbated respiratory symptoms in early childhood and must be monitored to regulate pharmacological therapy. However, parents' subjective perception of wheezing in their children is not always precise. We investigated the objective identification of children's wheezing by parents using a digital wheeze detector (WheezeScanTM, OMRON Healthcare Co. Ltd), its longitudinal usage patterns, and its relationship with SABA administration.

METHODS

We conducted a secondary nested analysis of data from the intervention arm of a multi-center randomized controlled trial completed in 2021-2022 in Berlin (Germany), London (United Kingdom), and Istanbul (Turkey). Children aged 4 to 84 months with doctor's diagnosed wheezing (GINA step 1 or 2) were included. Using an electronic diary (Wheeze-MonitorTM, TPS), parents monitored and recorded for 120 days at home the presence or absence of their child's wheezing, detected both, with WheezeScanTM ("objective" wheezing), and subjective ("perceived" wheezing). Parents also recorded the child's symptoms, medication intake, and family quality of life. Questionnaires regarding symptom control, quality of life, and parental self-efficacy were answered at baseline and after 90 and 120 days.

RESULTS

Eighty-one/87 families completed the intervention arm of the study. WheezeScanTM was on average used 0.7 (SD 0.6) times a day, with each patient reporting a positive, negative, or "error" outcome on average in 57%, 39%, and 5% of measurements, respectively. The use of WheezeScanTM declined slightly during the first 90 days of monitoring and steeply thereafter. Repeated usage of WheezeScanTM in the same day was more frequent after a "wheeze" (HR 1.5, 95% CI 1.37-1.65, p < 0.001) and an "error" (HR 2.01, 95% CI 1.70-2.38, p < 0.001) result, compared to a "no wheeze" outcome. The average per-patient daily agreement between "objective" and "perceived" wheezing/non-wheezing was 75% at the start of the monitoring period and only weakly persisted as time passed (Spearman's rho=0.09). The frequency of short-acting beta-2-agonists (SABA) administration was lower in days with closely interspaced consecutive device uses during which the patient's status was perceived as "never wheeze" (32/455, 7%) than in those perceived as "persistent wheeze" (53/119, 44%; OR 36.6, 95% CI [14.3, 94.1]).

CONCLUSION

Daily use of a digital WheezeScanTM at home allows parents to detect their child's unperceived wheezing and discloses to caregivers the longitudinal patterns of a child's wheezing disorder. Digital monitoring of wheezing also highlights poor adherence to guidelines in SABA administration for wheezing children, with under-treatment being much more frequent than over-treatment. This pioneering study opens new perspectives for further investigation of digital wheeze detectors in the early diagnosis and proper self-management of wheezing disorders in childhood.

Managing preschool wheeze: a qualitative study of parents' views and experiences

OBJECTIVE

The aim of this study was to explore parents' views and experiences of managing preschool wheeze, including opinions on the use of investigations to inform treatment pathways.

DESIGN

Purposive sampling was used to recruit 16 participants from 14 families across England and Wales. Qualitative data were collected via semi-structured interviews with parents of children aged 1-5 years with preschool wheeze, conducted on Microsoft (MS) Teams. Data were transcribed and analysed using thematic analysis, facilitated by NVivo software package.

RESULTS

Analysis generated four themes: (1) pathway to diagnosis, (2) medication management, (3) living with preschool wheeze and (4) improving preschool wheeze healthcare. Findings suggest a negative impact of preschool wheeze on families' lives, including high levels of worry and limiting capacity for work and travel. Barriers to effective management of preschool wheeze included inconsistent terminologies and diagnostic uncertainty alongside limited education and management support. Other barriers included parental concerns about medications, delayed investigations and challenges with accessing specialist care. Parents were in favour of performing investigations to guide treatment pathways.

CONCLUSION

Parents' views highlight the problem of diagnosing and treating preschool wheeze at multiple system levels. To improve management and ensure that services for children with preschool wheeze are effective, there is an urgent need for consistent terminology, a unified approach to guide investigations and treatments and for upskilling healthcare professionals in primary and secondary care.

Preschool wheeze and asthma endotypes- implications for future therapy

INTRODUCTION

Preschool wheeze and school-aged asthma present a large healthcare burden. Both conditions are now recognized to be heterogeneous, with similar symptom presentation but likely different underlying lung pathology.

AREAS COVERED

Current treatment options for preschool wheeze are constrained by extrapolations from the management of school-aged children with asthma. While most cases of asthma at school age are caused by classical atopic, eosinophilic, Type-2 driven asthma, only a quarter of preschool children with wheeze fall into this category. Targeting treatment to specific underlying mechanisms resulting in preschool wheeze may alter the progression to school age asthma. Novel biologics have revolutionized the management of severe, treatment-resistant school age asthma, but a limited evidence base limits their use in young children. There are several potential future non-steroid-based treatment options in development, of which bacterial lysates show the most promise.

EXPERT OPINION

Effective treatment of preschool wheeze may preserve lung function into later life, which may alter the progression trajectory toward school age asthma. Endotype-driven management will enable more effective treatment of both preschool wheeze and school age asthma.

Longitudinal transcriptional immune profiles and persistent wheezing in moderate-to-late preterm infants

BACKGROUND

Prematurity is associated with an increased risk of persistent wheezing but the underlying mechanisms are not well defined. The aim of this study was to identify blood transcriptional profiles associated with the development of wheezing in a cohort of moderate to late preterm infants and to define immune gene expression changes associated with wheezing.

MATERIALS AND METHODS

A convenience sample of a multicenter birth cohort (SAREPREM) of moderate-late preterm children followed during the first 3 years of life was analyzed. Children were enrolled in the first 2 weeks of life (Y0) and longitudinally evaluated at 1 (Y1), 2 (Y2), and 3 years (Y3) of age, for the presence of wheezing and to obtain samples for transcriptional profile analysis. Samples were processed on Illumina HT12 chips and genomic expression analyses performed with R programming, modular analysis for biological function, and QuSAGE for quantitative gene expression.

RESULTS

Seventy-six children were included in the study; 33 were classified as non-wheezing and 43 (56.6%) in the wheezing group. At Y0, children who developed wheezing had decreased expression of interferon genes and increased expression of B cell genes compared with the non-wheezing group. These changes in IFN and B cell gene expression were especially significant in children with late/persistent wheezing compared with transient wheezers.

CONCLUSIONS

Changes in IFN and B lymphocyte gene expression identified in early life suggest the existence of specific immunological mechanisms that play an important role in the development of wheezing in late-preterm infants.

The wheezy infant: A viewpoint from low-middle income countries

OBJECTIVE

To review the recent evidence in the literature of various aspects of recurrent/severe wheezing in children under 3 in low-middle income countries [LMICS].

SOURCES

A non-systematic review including articles in English. We mainly selected publications from the last 5 years. Studies on epidemiology, aetiology, diagnosis, treatment, and prevention were included in the search. We reviewed differential diagnoses of wheezing that focused on LMICS. We also reviewed aspects of prevention.

SUMMARY OF THE FINDINGS

Many epidemiological studies have shown a variable but significant number of wheezy infants [WI] cases in LMICS when compared to other countries. The differential diagnosis of causes of wheezing in this age group is mandatory, taking into account local facilities. Few treatment options have been well studied for this age group. In LMICS, a pragmatic approach could be considered, as described in the article. It is difficult to study primary prevention for WI and secondary prevention (mainly environmental) may have some impact. A schematic approach for recurrent wheezers is presented, which takes into account settings with limited resources.

CONCLUSION

Severely or recurrently wheezy children under 3 is a common clinical issue in LMICS. Studies on this age group are needed to reduce the significant morbidity. It may be possible to lower the high burden of wheezing in this age group by selecting the phenotype which may respond to inhaled steroids.

European Respiratory Society statement on preschool wheezing disorders: updated definitions, knowledge gaps and proposed future research directions

Since the publication of the European Respiratory Society (ERS) task force reports on the management of preschool wheezing in 2008 and 2014, a large body of evidence has accumulated suggesting that the clinical phenotypes that were proposed (episodic (viral) wheezing and multiple-trigger wheezing) do not relate to underlying airway pathology and may not help determine response to treatment. Specifically, using clinical phenotypes alone may no longer be appropriate, and new approaches that can be used to inform clinical care are needed for future research. This ERS task force reviewed the literature published after 2008 related to preschool wheezing and has suggested that the criteria used to define wheezing disorders in preschool children should include age of diagnosis (0 to <6 years), confirmation of wheezing on at least one occasion, and more than one episode of wheezing ever. Furthermore, diagnosis and management may be improved by identifying treatable traits, including inflammatory biomarkers (blood eosinophils, aeroallergen sensitisation) associated with type-2 immunity and differential response to inhaled corticosteroids, lung function parameters and airway infection. However, more comprehensive use of biomarkers/treatable traits in predicting the response to treatment requires prospective validation. There is evidence that specific genetic traits may help guide management, but these must be adequately tested. In addition, the task force identified an absence of caregiver-reported outcomes, caregiver/self-management options and features that should prompt specialist referral for this age group. Priorities for future research include a focus on identifying 1) mechanisms driving preschool wheezing; 2) biomarkers of treatable traits and efficacy of interventions in those without allergic sensitisation/eosinophilia; 3) the need to include both objective outcomes and caregiver-reported outcomes in clinical trials; 4) the need for a suitable action plan for children with preschool wheezing; and 5) a definition of severe/difficult-to-treat preschool wheezing.

The quality of paediatric asthma guidelines: evidence underpinning diagnostic test recommendations from a meta-epidemiological study

BACKGROUND

Asthma is one of the most frequent reasons children visit a general practitioner (GP). The diagnosis of childhood asthma is challenging, and a variety of diagnostic tests for asthma exist. GPs may refer to clinical practice guidelines when deciding which tests, if any, are appropriate, but the quality of these guidelines is unknown.

OBJECTIVES

To determine (i) the methodological quality and reporting of paediatric guidelines for the diagnosis of childhood asthma in primary care, and (ii) the strength of evidence supporting diagnostic test recommendations.

DESIGN

Meta-epidemiological study of English-language guidelines from the United Kingdom and other high-income countries with comparable primary care systems including diagnostic testing recommendations for childhood asthma in primary care. The AGREE-II tool was used to assess the quality and reporting of the guidelines. The quality of the evidence was assessed using GRADE.

RESULTS

Eleven guidelines met the eligibility criteria. The methodology and reporting quality varied across the AGREE II domains (median score 4.5 out of 7, range 2-6). The quality of evidence supporting diagnostic recommendations was generally of very low quality. All guidelines recommended the use of spirometry and reversibility testing for children aged ≥5 years, however, the recommended spirometry thresholds for diagnosis differed across guidelines. There were disagreements in testing recommendations for 3 of the 7 included tests.

CONCLUSIONS

The variable quality of guidelines, lack of good quality evidence, and inconsistent recommendations for diagnostic tests may contribute to poor clinician adherence to guidelines and variation in testing for diagnosing childhood asthma.

Critical reappraisal of short-acting bronchodilators for pediatric respiratory diseases

Short-acting bronchodilators are a class of medications commonly used to treat asthma, chronic obstructive pulmonary disease, and other respiratory conditions. The use of these medications has evolved over time as we have gained a better understanding of their effectiveness and safety in the pediatric population. This comprehensive review synthesizes the current understanding of short-acting β2-agonists and short-acting anticholinergics in children. It addresses indications, contraindications, safety considerations, and highlights areas where further research is needed to guide the most effective use of short-acting bronchodilators.

High-Flow Humidified Oxygen as an Early Intervention in Children With Acute Severe Asthma: Protocol for a Feasibility Randomized Controlled Trial

BACKGROUND

Acute severe asthma (ASA) is a leading cause of hospital attendance in children. Standard first-line therapy consists of high-dose inhaled bronchodilators plus oral corticosteroids. Treatment for children who fail to respond to first-line therapy is problematic: the use of intravenous agents is inconsistent, and side effects are frequent. High-flow humidified oxygen (HiFlo) is widely used in respiratory conditions and is increasingly being used in ASA, but with little evidence for its effectiveness. A well-designed, adequately powered randomized controlled trial (RCT) of HiFlo therapy in ASA is urgently needed, and feasibility data are required to plan such an RCT. In this study, we describe the protocol for a feasibility study designed to fill this knowledge gap.

OBJECTIVE

This study aims to establish whether a full RCT of early HiFlo therapy in children with ASA can be conducted successfully and safely, to establish whether recruitment using deferred consent is practicable, and to define appropriate outcome measures and sample sizes for a definitive RCT. The underlying hypothesis is that early HiFlo therapy in ASA will reduce the need for more invasive treatments, allow faster recovery and discharge from hospital, and in both these ways reduce distress to children and their families.

METHODS

We conducted a feasibility RCT with deferred consent to assess the use of early HiFlo therapy in children aged 2 to 11 years with acute severe wheeze not responding to burst therapy (ie, high-dose inhaled salbutamol with or without ipratropium). Children with a Preschool Respiratory Assessment Measure score ≥5 after burst therapy were randomized to commence HiFlo therapy or follow standard care. The candidate primary outcomes assessed were treatment failure requiring escalation and time to meet hospital discharge criteria. Patient and parent experiences were also assessed using questionnaires and telephone interviews.

RESULTS

The trial was opened to recruitment in February 2020 but was paused for 15 months owing to the COVID-19 pandemic. The trial was reopened at the lead site in July 2021 and opened at the other 3 sites from August to December 2022. Recruitment was completed in June 2023.

CONCLUSIONS

This feasibility RCT of early HiFlo therapy in children with ASA recruited to the target despite major disturbances owing to the COVID-19 pandemic. The data are currently being analyzed and will be published separately.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Registry ISRCTN78297040; https://www.isrctn.com/ISRCTN78297040.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54081.

Vitamin D Level and Immune Modulation in Children with Recurrent Wheezing

INTRODUCTION AND AIM

A direct causal relationship between vitamin D (vit D) deficiency and recurrent wheezing has not been proven. The present study investigated the role of vit D in enhancing the risk of asthma or recurrent wheezing by modifying the intensity of the inflammatory process.

MATERIAL AND METHOD

Forty children with wheezing presenting at the emergency service and sixteen healthy control subjects were included in the study. Children with wheezing were either in the first episode (20) or with recurrent wheezing (20). Children with chronic diseases, and other conditions that present with acute wheezing or that might influence the vit D level, were excluded. Blood samples were taken at presentation and 3-6 months later, to evaluate the serum levels of total IgE, vit D, IL-10 and IL-31. Statistical analysis was performed using the SPSS 25 program, with a significance level of p < 0.05.

RESULTS AND CONCLUSION

The vit D level was lower in patients with recurrent wheezing compared with those with a single episode and with the control group, and this increased with time. IL-10 was significantly higher in children with wheezing than in the control group, with the highest values in those with an acute episode of wheezing. IL-31 was higher in children with recurrent wheezing than in those with a first episode only at the initial point, while at the final time point it was lower. Low levels of vit D appear to be detected more frequently in recurrent wheezing than in simple wheezing. Immune modulation, as measured by Th2 status reflected by IL-10 and IL-31 levels, appears to depend on the wheezing phenotype and on the general health status.

A systematic review and meta-analysis on absolute eosinophil counts and the risk of asthma in preschool children with wheezing: An EAACI Task Force Report

Preschool children with wheezing disorders pose diagnostic and therapeutic challenges and consume substantial healthcare resources. Peripheral eosinophil blood count (EBC) has been proposed as a potential indicator for future asthma development. This review by the European Academy of Allergy and Clinical Immunology (EAACI) Preschool Wheeze Task Force aimed to provide systematic evidence for the association between increased EBC and the risk of future asthma, as well as to identify potential cutoff values. In February 2023, a search of PubMed, EMBASE, and Cochrane Library databases was conducted to identify studies comparing EBCs in preschool children with wheezing who continued to wheeze later in life and those who did not. Included observational studies focused on children aged <6 years with a wheezing disorder, assessment of their EBCs, and subsequent asthma status. No language or publication date restrictions were applied. Among the initial 3394 studies screened, 10 were included in the final analysis, involving 1225 patients. The data from these studies demonstrated that high EBC in preschool children with wheezing is associated with future asthma development, with odds ratios of 1.90 (95% CI: 0.45-7.98, p = .38), 2.87 (95% CI: 1.38-5.95, p < .05), and 3.38 (95% CI: 1.72-6.64, p < .05) for cutoff values in the <300, 300-449, and ≥450 cells/μL ranges, respectively. Defining a specific cutoff point for an elevated EBC lacks consistency, but children with EBC >300 cells/μL are at increased risk of asthma. However, further research is needed due to the limitations of the included studies. Future investigations are necessary to fully elucidate the discussed association.

Clinical Predictors of Severe Exacerbations in Pediatric Patients With Recurrent Wheezing

Introduction Wheezing is common in preschool-aged children, affecting about half of all children within their first six years of life. Children who have recurrent wheezing experience disease-related morbidity, including increased emergency visits and hospitalizations. Early-life lower respiratory tract viral infections are linked to recurrent wheezing and eventual asthma onset. Identifying high-risk children is crucial, with the frequency and severity of wheezing episodes being good predictors of long-term outcomes. Aim To identify predictors of severe exacerbations in children with recurrent wheezing. Methods We conducted a retrospective cohort study involving 168 pediatric patients with recurrent wheezing followed up at our outpatient clinic. The outcome of interest was the occurrence of a severe exacerbation, defined as any exacerbation requiring hospitalization and the need for supplemental oxygenation or ventilatory support. Results The median age of the first wheezing exacerbation was five months, with a predominance of the male gender. Approximately two-thirds of the patients had a family history of atopy. Comorbid allergic rhinitis and atopic dermatitis were present in 15.4% and 16.7% of patients, respectively. Twenty percent of patients had a severe wheezing exacerbation as the first form of presentation, and 30% presented at least one severe exacerbation from the first presentation to the last follow-up. Patients with severe exacerbations were younger at the first episode (median age 4 months, IQR 2-7, versus 7 months, IQR 4-12, p=0.027) and more frequently had a family history of atopy (71.7% versus 55.6%, p=0.050). In this cohort, patients who initially presented with a severe episode are at increased risk of incident severe exacerbations during follow-up, HR 2.24 (95%CI 1.01-4.95). Conclusions We know that the severity of exacerbations in children with recurrent wheezing correlates with the long-term outcomes of the disease. Therefore, preventing severe exacerbations can positively impact the prognosis of these patients. In this analysis, we found independent predictors of severe exacerbations to be the first clinical episode before the age of three months and a family history of atopy. We also found that patients whose initial presentation was severe have a higher risk of new severe exacerbations. Therefore, these subgroups of patients should be closely monitored by pediatricians.

Clinical efficacy and satisfaction of a digital wheeze detector in a multicentre randomised controlled trial: the WheezeScan study

Introduction

Wheezing is common in preschool children and its clinical assessment often challenging for caretakers. This study aims to evaluate the impact of a novel digital wheeze detector (WheezeScan™) on disease control in a home care setting.

Methods

A multicentre randomised open-label controlled trial was conducted in Berlin, Istanbul and London. Participants aged 4-84 months with a doctor's diagnosis of recurrent wheezing in the past 12 months were included. While the control group followed usual care, the intervention group received the WheezeScan™ for at-home use for 120 days. Parents completed questionnaires regarding their child's respiratory symptoms, disease-related and parental quality of life, and caretaker self-efficacy at baseline (T0), 90 days (T1) and 4 months (T2).

Results

A total of 167 children, with a mean±sd age of 3.2±1.6 years, were enrolled in the study (intervention group n=87; control group n=80). There was no statistically significant difference in wheeze control assessed by TRACK (mean difference 3.8, 95% CI -2.3-9.9; p=0.2) at T1 between treatment groups (primary outcome). Children's and parental quality of life and parental self-efficacy were comparable between both groups at T1. The evaluation of device usability and perception showed that parents found it useful.

Conclusion

In the current study population, the wheeze detector did not show significant impact on the home management of preschool wheezing. Hence, further research is needed to better understand how the perception and usage behaviour may influence the clinical impact of a digital support.

Genetics of preschool wheeze and its progression to childhood asthma

Wheezing is a common and heterogeneous condition in preschool children. In some countries, the prevalence can be as high as 30% and up to 50% of all children experience wheezing before the age of 6. Asthma often starts with preschool wheeze, but not all wheezing children will develop asthma at school age. At this moment, it is not possible to accurately predict which wheezing children will develop asthma. Recently, studying the genetics of wheeze and the childhood-onset of asthma have grown in interest. Childhood-onset asthma has a stronger heritability in comparison with adult-onset asthma. In early childhood asthma exacerbations, CDHR3, which encodes the receptor for Rhinovirus C, was identified, as well as IL33, and the 17q locus that includes GSDMB and ORMDL3 genes. The 17q locus is the strongest wheeze and childhood-onset asthma locus, and was shown to interact with many environmental factors, including smoking and infections. Finally, ANXA1 was recently associated with early-onset, persistent wheeze. ANXA1 may help resolve eosinophilic inflammation. Overall, despite its complexities, genetic approaches to unravel the early-onset of wheeze and asthma are promising, since these shed more light on mechanisms of childhood asthma-onset. Implicated genes point toward airway epithelium and its response to external factors, such as viral infections. However, the heterogeneity of wheeze phenotypes complicates genetic studies. It is therefore important to define accurate wheezing phenotypes and forge larger international collaborations to gain a better understanding of the pathways underlying early-onset asthma.

Understanding progression from pre-school wheezing to school-age asthma: Can modern data approaches help?

Preschool wheezing and childhood asthma create a heavy disease burden which is only exacerbated by the complexity of the conditions. Preschool wheezing exhibits both "curricular" and "aetiological" heterogeneity: that is, heterogeneity across patients both in the time-course of its development and in its underpinning pathological mechanisms. Since these are not fully understood, but clinical presentations across patients may nonetheless be similar, current diagnostic labels are imprecise-not mapping cleanly onto underlying disease mechanisms-and prognoses uncertain. These uncertainties also make a identifying new targets for therapeutic intervention difficult. In the past few decades, carefully designed birth cohort studies have collected "big data" on a large scale, incorporating not only a wealth of longitudinal clinical data, but also detailed information from modalities as varied as imaging, multiomics, and blood biomarkers. The profusion of big data has seen the proliferation of what we term "modern data approaches" (MDAs)-grouping together machine learning, artificial intelligence, and data science-to make sense and make use of this data. In this review, we survey applications of MDAs (with an emphasis on machine learning) in childhood wheeze and asthma, highlighting the extent of their successes in providing tools for prognosis, unpicking the curricular heterogeneity of these conditions, clarifying the limitations of current diagnostic criteria, and indicating directions of research for uncovering the etiology of the diseases underlying these conditions. Specifically, we focus on the trajectories of childhood wheeze phenotypes. Further, we provide an explainer of the nature and potential use of MDAs and emphasize the scope of what we can hope to achieve with them.

Antiasthmatic prescriptions in children with and without congenital anomalies: a population-based study

OBJECTIVES

To explore the risk of being prescribed/dispensed medications for respiratory symptoms and breathing difficulties in children with and without congenital anomalies.

DESIGN

A EUROlinkCAT population-based data linkage cohort study. Data on children with and without congenital anomalies were linked to prescription databases to identify children who did/did not receive antiasthmatic prescriptions. Data were analysed by age, European region, class of antiasthmatic, anomaly, sex, gestational age and birth cohort.

SETTING

Children born 2000-2014 in six regions within five European countries.

PARTICIPANTS

60 662 children with congenital anomalies and 1 722 912 reference children up to age 10 years.

PRIMARY OUTCOME MEASURE

Relative risks (RR) of >1 antiasthmatic prescription in a year, identified using Anatomical Therapeutic Chemical classification codes beginning with R03.

RESULTS

There were significant differences in the prescribing of antiasthmatics in the six regions. Children with congenital anomalies had a significantly higher risk of being prescribed antiasthmatics (RR 1.41, 95% CI 1.35 to 1.48) compared with reference children. The increased risk was consistent across all regions and all age groups. Children with congenital anomalies were more likely to be prescribed beta-2 agonists (RR 1.71, 95% CI 1.60 to 1.83) and inhaled corticosteroids (RR 1.74, 95% CI 1.61 to 1.87). Children with oesophageal atresia, genetic syndromes and chromosomal anomalies had over twice the risk of being prescribed antiasthmatics compared with reference children. Children with congenital anomalies born <32 weeks gestational age were over twice as likely to be prescribed antiasthmatics than those born at term (RR 2.20, 95% CI 2.10 to 2.30).

CONCLUSION

This study documents the additional burden of respiratory symptoms and breathing difficulties for children with congenital anomalies, particularly those born preterm, compared with children without congenital anomalies in the first 10 years of life. These findings are beneficial to clinicians and healthcare providers as they identify children with greater morbidity associated with respiratory symptoms, as indicated by antiasthmatic prescriptions.

Bronchodilator response by interrupter technique to guide management of preschool wheeze

OBJECTIVE

We examined relationships between clinical features and pulmonary function before and after inhaled corticosteroid (ICS) treatment in wheezy preschool children, and specifically, whether measuring bronchodilator response (BDR) could predict benefit from ICS.

DESIGN

Clinical non-randomised intervention study SETTING: Secondary care.

PATIENTS

Preschool children (2 years to <6 years) with recurrent wheeze.

INTERVENTIONS

Inhaled beta-agonist, ICS.

OUTCOME MEASURES

We measured prebronchodilator and postbronchodilator interrupter resistance (Rint) and symptom scores at 0 (V1), 4 (V2) and 12 (V3) weeks. At V2, those with a predetermined symptom level commenced ICS. Modified Asthma Predictive Index (mAPI) and parental perception of response to bronchodilator were recorded. Response to ICS was defined as a reduction in daily symptom score of >0.26. Positive BDR was defined as fall in Rint of ≥0.26 kPa.s/L, ≥35% predicted or ≥1.25 Z Scores.

RESULTS

Out of 138 recruited children, 67 completed the full study. Mean (SD) prebronchodilator Rint at V2 was 1.22 (0.35) kPa.s/L, and fell after starting ICS (V3) to 1.09 (0.33) kPa.s/L (p<0.001), while mean (SD) daily symptom score fell from 0.56 (0.36) to 0.28 (0.36) after ICS (p<0.001). Positive Rint BDR before ICS (at V1 and/or V2), using all three threshold criteria, was significantly associated with response to ICS on symptom scores at V3 (p<0.05). mAPI was not significantly associated with response to ICS, and parents' perception of response to bronchodilator was not related to measured Rint BDR .

CONCLUSIONS

Rint BDR may be helpful in selecting which wheezy preschool children are likely to benefit from ICS.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Pre-school wheeze hospital presentations: A demographic profile and review of clinical management

AIM

Pre-school wheeze is a common hospital presentation in Australasia. The aim of this study was to describe the regional hospital presentation and cost of pre-school wheeze.

METHODS

Audit of children diagnosed with pre-school wheeze at two hospitals in Auckland, New Zealand from October 2017 to September 2019. Guideline adherence was determined.

RESULTS

One hundred and ninety-two children made 247 pre-school wheeze hospital presentations. Pre-school wheeze accounted for a larger proportion of acute hospital presentations for Māori versus non-Māori children (rate ratio 1.76, 95% confidence intervals 1.32-2.31). Hospital representations with pre-school wheeze occurred in 38/192 (20%) children. The proportion with a pre-school wheeze representation was larger for Māori than non-Māori (30% vs. 16%, P = 0.02). Pre-school wheeze event median length of stay increased as household deprivation increased (P = 0.01). Clinical severity of 247 pre-school wheeze episodes was mild (n = 64, 26%), moderate (n = 153, 62%) and severe (n = 30, 12%). Of 244 episodes, inhaled bronchodilators only were given for 149 (61%), oxygen for 54 (22%) and intravenous treatment for 41 (17%). Hospital guideline use was evident in 164/247 (66%) episodes. Neither clinical severity nor treatment intensity varied with child sex, age or ethnicity or household deprivation. The estimated median (interquartile range) direct medical costs of each pre-school wheeze episode were NZ$1279 (NZ$774-2158).

CONCLUSIONS

In Auckland, pre-school wheeze accounts for a larger proportion of acute hospital presentations for Māori compared with non-Māori and Māori children have increased odds of pre-school wheeze readmissions. Length of hospital stay for pre-school wheeze episodes increased with household deprivation. In this audit pre-school wheeze guideline adherence was poor.

Phenotype and endotype based treatment of preschool wheeze

INTRODUCTION

Preschool wheeze (PSW) is a significant public health issue, with a high presentation rate to emergency departments, recurrent symptoms, and severe exacerbations. A heterogenous condition, PSW comprises several phenotypes that may relate to a range of pathobiological mechanisms. However, treating PSW remains largely generalized to inhaled corticosteroids and a short acting beta agonist, guided by symptom-based labels that often do not reflect underlying pathways of disease.

AREAS COVERED

We review the observable features and characteristics used to ascribe phenotypes in children with PSW and available pathobiological evidence to identify possible endotypes. These are considered in the context of treatment options and future research directions. The role of machine learning (ML) and modern analytical techniques to identify patterns of disease that distinguish phenotypes is also explored.

EXPERT OPINION

Distinct clusters (phenotypes) of severe PSW are characterized by different underlying mechanisms, some shared and some unique. ML-based methodologies applied to clinical, biomarker, and environmental data can help design tools to differentiate children with PSW that continues into adulthood, from those in whom wheezing resolves, identifying mechanisms underpinning persistence and resolution. This may help identify novel therapeutic targets, inform mechanistic studies, and serve as a foundation for stratification in future interventional therapeutic trials.

Basic clinical management of preschool wheeze

Preschool wheeze is very common and often difficult to treat. Most children do not require any investigations; only a detailed history and physical examination to ensure an alternative diagnosis is not being missed; and the differential diagnosis, and hence investigation protocols for the child in whom a major illness is suspected, shows geographical variation. The pattern of symptoms may be divided into episodic viral and multiple trigger to guide treatment, but the pattern of symptoms must be re-assessed regularly. However, symptom patterns are a poor guide to underlying pathology. Attention to the proper use of spacers, and adverse environmental exposures such as tobacco smoke exposure, is essential. There are no disease-modifying therapies, so therapy is symptomatic. This paper reviews recent advances in treatment, including new data on the place of leukotriene receptor antagonists, prednisolone for acute attacks of wheeze, and antibiotics, based on new attempts to understand the underlying pathology in a way that is clinically practical.

Demystifying controversies in preschool wheeze

INTRODUCTION

Wheezing disorders in preschool children are common. Current treatment approaches assume all preschool wheezers are the same and will respond to a short course of oral corticosteroids (OCS) during acute attacks and subsequent maintenance inhaled corticosteroids (ICS) to prevent future attacks. But we have increasing evidence showing preschool wheezing disorders are markedly heterogeneous and the response to corticosteroids either during acute attacks or as maintenance therapy can be variable between patients and is determined by disease severity and underlying pathological phenotype.

AREAS COVERED

The aim of this review is to discuss recent evidence which will help to explain a few critical pathophysiological concepts that are often misunderstood, thus helping to demystify the controversies that often surround preschool wheezing disorders and can contribute to ineffective management.

EXPERT OPINION

Preschool wheezing disorders are distinct from school-age allergic asthma. There is little evidence to support the use of oral corticosteroids for acute attacks. A staged approach to confirm the diagnosis, and objective tests to determine the pathological phenotype of preschool wheeze is essential prior to initiating maintenance therapy to control symptoms and prevent attacks in children with recurrent preschool wheeze.

Personalised management and supporting individuals to live with their asthma in a primary care setting

INTRODUCTION

Complementing recognition of biomedical phenotypes, a primary care approach to asthma care recognizes diversity of disease, health beliefs, and lifestyle at a population and individual level.

AREAS COVERED

We review six aspects of personalized care particularly pertinent to primary care management of asthma: personalizing support for individuals living with asthma; targeting asthma care within populations; managing phenotypes of wheezy pre-school children; personalizing management to the individual; meeting individual preferences for provision of asthma care; optimizing digital approaches to enhance personalized care.

EXPERT OPINION

In a primary care setting, personalized management and supporting individuals to live with asthma extend beyond the contemporary concepts of biological phenotypes and pharmacological 'treatable traits' to encompass evidence-based tailored support for self-management, and delivery of patient-centered care including motivational interviewing. It extends to how we organize clinical practiceand the choices provided in mode of consultation. Diagnostic uncertainty due to recognition of phenotypes of pre-school wheeze remains a challenge for primary care. Digital health can support personalized management, but there are concerns about increasing inequities. This broad approach reflects the traditionally holistic ethos of primary care ('knowing their patients and understanding their communities'), but the core concepts resonate with all healthcare.

Advances in the pathogenesis and personalised treatment of paediatric asthma

The diversity of pathology of severe paediatric asthma demonstrates that the one-size-fits-all approach characterising many guidelines is inappropriate. The term "asthma" is best used to describe a clinical syndrome of wheeze, chest tightness, breathlessness, and sometimes cough, making no assumptions about underlying pathology. Before personalising treatment, it is essential to make the diagnosis correctly and optimise basic management. Clinicians must determine exactly what type of asthma each child has. We are moving from describing symptom patterns in preschool wheeze to describing multiple underlying phenotypes with implications for targeting treatment. Many new treatment options are available for school age asthma, including biological medicines targeting type 2 inflammation, but a paucity of options are available for non-type 2 disease. The traditional reliever treatment, shortacting β2 agonists, is being replaced by combination inhalers containing inhaled corticosteroids and fast, longacting β2 agonists to treat the underlying inflammation in even mild asthma and reduce the risk of asthma attacks. However, much decision making is still based on adult data extrapolated to children. Better inclusion of children in future research studies is essential, if children are to benefit from these new advances in asthma treatment.

Dysregulation of iron homeostasis in airways associated with persistent preschool wheezing

BACKGROUND

Currently, there are no reliable clinical tools available to identify persistent asthma symptoms among preschool children with recurrent wheezing. We investigated iron homeostasis in the airways of preschoolers with recurrent wheezing and assessed whether iron homeostasis-related indices may reliably predict persistent wheezing.

METHODS

Iron levels and mRNA expression levels of iron homeostasis molecules were examined in bronchoalveolar lavage samples from 89 preschoolers with recurrent wheezing and 56 controls, with a 12-month follow-up conducted. Risk factors for persistent wheezing were identified using least absolute shrinkage and selection operator and multivariate logistic regression. The addition of predictive values of iron indices to the modified Asthma Predictive Index (mAPI) or clinical predictors was determined using area under receiver operating characteristic curves (AUC).

RESULTS

Preschoolers with recurrent wheezing had reduced iron levels in their airways, associated with significantly decreased expression of iron export molecule SLC40A1 and increased expression of iron intake factor TFR1 and iron storage factors FTH and FTL. Risk factors for persistent wheezing included mAPI positivity, iron predictors (lower expression of SLC40A1 and higher expression of FTL), and clinical predictors (aeroallergen sensitivity, shorter breastfeeding duration, and earlier age of first wheezing episode). The addition of information on iron predictors significantly enhanced the power of clinical predictors (AUC: 84%, increase of 12%) and mAPI (AUC: 81%, increase of 14%).

CONCLUSIONS

Iron homeostasis is altered in the airways of preschoolers with recurrent wheezing. Adding information on iron-related indices to clinical information significantly improves accurate prediction of persistent wheezing in preschool-aged children.

The ADEM2 project: early pathogenic mechanisms of preschool wheeze and a randomised controlled trial assessing the gain in health and cost-effectiveness by application of the breath test for the diagnosis of asthma in wheezing preschool children

BACKGROUND

The prevalence of asthma-like symptoms in preschool children is high. Despite numerous efforts, there still is no clinically available diagnostic tool to discriminate asthmatic children from children with transient wheeze at preschool age. This leads to potential overtreatment of children outgrowing their symptoms, and to potential undertreatment of children who turn out to have asthma. Our research group developed a breath test (using GC-tof-MS for VOC-analysis in exhaled breath) that is able to predict a diagnosis of asthma at preschool age. The ADEM2 study assesses the improvement in health gain and costs of care with the application of this breath test in wheezing preschool children.

METHODS

This study is a combination of a multi-centre, parallel group, two arm, randomised controlled trial and a multi-centre longitudinal observational cohort study. The preschool children randomised into the treatment arm of the RCT receive a probability diagnosis (and corresponding treatment recommendations) of either asthma or transient wheeze based on the exhaled breath test. Children in the usual care arm do not receive a probability diagnosis. Participants are longitudinally followed up until the age of 6 years. The primary outcome is disease control after 1 and 2 years of follow-up. Participants of the RCT, together with a group of healthy preschool children, also contribute to the parallel observational cohort study developed to assess the validity of alternative VOC-sensing techniques and to explore numerous other potential discriminating biological parameters (such as allergic sensitisation, immunological markers, epigenetics, transcriptomics, microbiomics) and the subsequent identification of underlying disease pathways and relation to the discriminative VOCs in exhaled breath.

DISCUSSION

The potential societal and clinical impact of the diagnostic tool for wheezing preschool children is substantial. By means of the breath test, it will become possible to deliver customized and high qualitative care to the large group of vulnerable preschool children with asthma-like symptoms. By applying a multi-omics approach to an extensive set of biological parameters we aim to explore (new) pathogenic mechanisms in the early development of asthma, creating potentially interesting targets for the development of new therapies.

TRIAL REGISTRATION

Netherlands Trial Register, NL7336, Date registered 11-10-2018.

Oscillometry to support clinical assessment in asthmatic preschoolers: Real-life impact

In preschoolers, asthma control is assessed clinically using history and physical examination. In certain centres, oscillometry is used to support clinical assessment; yet its clinical utility for asthma management remains to be quantified. The objectives were to determine if oscillometry, as adjunct to clinical assessment, influences asthma assessment, management and control, compared to clinical assessment alone in preschoolers. We conducted a cross-sectional study in children aged 3-5 years with a confirmed asthma diagnosis. Oscillometry-tested preschoolers were matched by propensity score to untested children. The co-primary outcomes, the likelihood of a persistent asthma phenotype and a maintenance therapy prescription at the index visit, were examined by multivariable logistic regression. Asthma control over the next year was examined by cumulative logistic regression in the nested retrospective cohort with available drug claim data. The cohort comprised 726 (249 oscillometry-tested; 477 untested) children with 57.4% male (median age: 4.6 years). Propensity score matching resulted in comparable groups. Compared to controls, oscillometry-tested children were more frequently labelled with a persistent phenotype (67% vs. 50%; adjusted OR [95% CI]: 2.34 [1.66-3.34]) with no significant difference in maintenance therapy prescription (65% vs. 58%; 1.37 [0.98-1.92]); but experienced a lower likelihood of poor control over the next year (adjusted OR [95% CI]: 0.24 [0.08-0.74]). The association between the addition of oscillometry to clinical assessment with more persistent phenotype labelling and better asthma control supports its clinical utility; no significant impact on maintenance therapy prescription was observed at the index visit.

What Have Mechanistic Studies Taught Us About Childhood Asthma?

Childhood asthma is a chronic heterogeneous syndrome consisting of different disease entities or phenotypes. The immunologic and cellular processes that occur during asthma development are still not fully understood but represent distinct endotypes. Mechanistic studies have examined the role of gene expression, protein levels, and cell types in early life development and the manifestation of asthma, many under the influence of environmental stimuli, which can be both protective and risk factors for asthma. Genetic variants can regulate gene expression, controlled partly by different epigenetic mechanisms. In addition, environmental factors, such as living space, nutrition, and smoking, can contribute to these mechanisms. All of these factors produce modifications in gene expression that can alter the development and function of immune and epithelial cells and subsequently different trajectories of childhood asthma. These early changes in a partially immature immune system can have dramatic effects (e.g., causing dysregulation), which in turn contribute to different disease endotypes and may help to explain differential responsiveness to asthma treatment. In this review, we summarize published studies that have aimed to uncover distinct mechanisms in childhood asthma, considering genetics, epigenetics, and environment. Moreover, a discussion of new, powerful tools for single-cell immunologic assays for phenotypic and functional analysis is included, which promise new mechanistic insights into childhood asthma development and therapeutic and preventive strategies.

Physicians' ability to recognize adventitious lung sounds

BACKGROUND

Lung auscultation is an important tool for diagnosing respiratory diseases. However, the ability of observers to recognize respiratory sounds varies considerably and depends on the sound. The present study aimed to assess the auscultatory skills of healthcare professionals and medical students.

METHODS

A total of 295 physicians (185 pediatricians, 69 pulmonologists, and 41 physicians of general/internal medicine and subspecialties), 55 residents, and 50 medical students participated in the survey. They listened to five audio-recorded respiratory sounds and described them in free-form answers.

RESULTS

The rates of correct answers were 55.2% for fine crackles, 74.5% for coarse crackles, 72.2% for wheezes, 18.75% for squawks, and 11.25% for pleural friction rub. The medical specialty was correlated with the correct answers and both pediatricians and physicians of general/internal medicine and subspecialties recognized fewer sounds compared with respiratory physicians (odds ratio [OR]: 0.37; confidence interval [CI]: 0.22-0.62; p < 0.001 and, OR: 0.47; CI: 0.22-0.99, p = 0.048, respectively). Years of experience were negatively correlated with the number of correct answers (OR: 0.73; CI:0.62-0.84; p = 0.001).

CONCLUSIONS

Gaps remain in both terminology and recognition of lung sounds among a wide population of Greek physicians. Less experienced physicians perform better on lung auscultation, indicating that continuing education with critical feedback should be offered.

Bronchial Remodeling-based Latent Class Analysis Predicts Exacerbations in Severe Preschool Wheezers

Rationale: Children with preschool wheezing represent a very heterogeneous population with wide variability regarding their clinical, inflammatory, obstructive, and/or remodeling patterns. We hypothesized that assessing bronchial remodeling would help clinicians to better characterize severe preschool wheezers. Objectives: The main objective was to identify bronchial remodeling-based latent classes of severe preschool wheezers. Secondary objectives were to compare cross-sectional and longitudinal clinical and biological data between classes and to assess the safety of bronchoscopy. Methods: This double-center prospective study (NCT02806466) included severe preschool wheezers (1-5 yr old) requiring fiberoptic bronchoscopy. Bronchial remodeling parameters (i.e., epithelial integrity, reticular basement membrane [RBM] thickness, mucus gland, fibrosis and bronchial smooth muscle [BSM] areas, the density of blood vessels, and RBM-BSM distance) were assessed and evaluated by latent class analysis. An independent cohort of severe preschool wheezers (NCT04558671) was used to validate our results. Measurements and Main Results: Fiberoptic bronchoscopy procedures were well tolerated. A two-class model was identified: Class BR1 was characterized by increased RBM thickness, normalized BSM area, the density of blood vessels, decreased mucus gland area, fibrosis, and RBM-BSM distance compared with Class BR2. No significant differences were found between classes in the year before fiberoptic bronchoscopy. By contrast, Class BR1 was associated with a shorter time to first exacerbation and an increased risk of both frequent (3 or more) and severe exacerbations during the year after bronchoscopy in the two cohorts. Conclusions: Assessing bronchial remodeling identified severe preschool wheezers at risk of frequent and severe subsequent exacerbations with a favorable benefit to risk ratio.

Key recommendations for primary care from the 2022 Global Initiative for Asthma (GINA) update

The Global Initiative for Asthma (GINA) was established in 1993 by the World Health Organization and the US National Heart Lung and Blood Institute to improve asthma awareness, prevention and management worldwide. GINA develops and publishes evidence-based, annually updated resources for clinicians. GINA guidance is adopted by national asthma guidelines in many countries, adapted to fit local healthcare systems, practices, and resource availability. GINA is independent of industry, funded by the sale and licensing of its materials. This review summarizes key practical guidance for primary care from the 2022 GINA strategy report. It provides guidance on confirming the diagnosis of asthma using spirometry or peak expiratory flow. GINA recommends that all adults, adolescents and most children with asthma should receive inhaled corticosteroid (ICS)-containing therapy to reduce the risk of severe exacerbations, either taken regularly, or (for adults and adolescents with "mild" asthma) as combination ICS-formoterol taken as needed for symptom relief. For patients with moderate-severe asthma, the preferred regimen is maintenance-and-reliever therapy (MART) with ICS-formoterol. Asthma treatment is not "one size fits all"; GINA recommends individualized assessment, adjustment, and review of treatment. As many patients with difficult-to-treat or severe asthma are not referred early for specialist review, we provide updated guidance for primary care on diagnosis, further investigation, optimization and treatment of severe asthma across secondary and tertiary care. While the GINA strategy has global relevance, we recognize that there are special considerations for its adoption in low- and middle-income countries, particularly the current poor access to inhaled medications.

Application of deep learning for bronchial asthma diagnostics using respiratory sound recordings

Methods of computer-assisted diagnostics that utilize deep learning techniques on recordings of respiratory sounds have been developed to diagnose bronchial asthma. In the course of the study an anonymous database containing audio files of respiratory sound recordings of patients suffering from different respiratory diseases and healthy volunteers has been accumulated and used to train the software and control its operation. The database consists of 1,238 records of respiratory sounds of patients and 133 records of volunteers. The age of tested persons was from 18 months to 47 years. The sound recordings were captured during calm breathing at four points: in the oral cavity, above the trachea, at the chest, the second intercostal space on the right side, and at the point on the back. The developed software provides binary classifications (diagnostics) of the type: "sick/healthy" and "asthmatic patient/non-asthmatic patient and healthy". For small test samples of 50 (control group) to 50 records (comparison group), the diagnostic sensitivity metric of the first classifier was 88%, its specificity metric -86% and accuracy metric -87%. The metrics for the classifier "asthmatic patient/non-asthmatic patient and healthy" were 92%, 82%, and 87%, respectively. The last model applied to analyze 941 records in asthmatic patients indicated the correct asthma diagnosis in 93% of cases. The proposed method is distinguished by the fact that the trained model enables diagnostics of bronchial asthma (including differential diagnostics) with high accuracy irrespective of the patient gender and age, stage of the disease, as well as the point of sound recording. The proposed method can be used as an additional screening method for preclinical bronchial asthma diagnostics and serve as a basis for developing methods of computer assisted patient condition monitoring including remote monitoring and real-time estimation of treatment effectiveness.

Association between Environmental Exposures and Asthma among Children in King Williams Town, South Africa

The study aimed to assess the association between environmental exposure and asthma among children between 3 and 12 years old in King Williams Town, South Africa. A quantitative case-control study was conducted at Grey Hospital to assess the association between environmental exposure and asthma among children who reside in King Williams Town. Of the total 566 study participants, 50.5% (286) had asthma while 49.5% did not. Socio-demographic factors associated with asthma in children were being within the age group 9-12 years (OR 1.74, CI 95% 1.09-2.78) and India ethnicity (OR 0.20, CI 95% 0.08-0.48). Factors associated with asthma were weight within 25-35 kg (OR 1.64, CI 95% 1.11-2.42) and BMI within 15-20 (OR 4.80, CI 95% 2.80-8.22). Environmental risk factors associated with asthma were indoor exposure to tobacco smoke from mothers of the participants (OR 5.45, CI 95% 3.08-9.65) and from fathers (OR 4.37; CI 95% 2.77-6.90). Abstaining from eating seafood appeared to be protective from developing asthma (OR 0.01; CI 95% 0.00-0.05). The study found no significant association between outdoor environmental exposures and childhood asthma. The age of participant, weight, BMI, exposure to environmental tobacco smoke (ETS), and eating seafood had significant correlations with childhood asthma. Strengthening the evaluation of children healthcare and encouraging smoking cessation among parents could reduce exposure to environmental asthma triggers among children.

Pulse oximetry respiratory monitoring for assessment of acute childhood wheeze

OBJECTIVE

There is a lack of objective measures to assess children with acute wheezing episodes. Increased respiratory rate (RR) and pulsus paradoxus (PP) are recognised markers, but poorly recorded in practice. We examined whether they can be reliably assessed from a pulse oximeter plethysmogram ('pleth') trace and predict clinical outcome.

PATIENTS AND METHODS

We studied 44 children aged 1-7 years attending hospital with acute wheeze, following initial 'burst' bronchodilator therapy (BT), and used custom software to measure RR and assess PP from oximeter pleth traces. Traces were examined for quality, and the accuracy of the RR measurement was validated against simultaneous respiratory inductive plethysmography (RIP). RR and PP at 1 hour after BT were compared with clinical outcomes.

RESULTS

RR from pleth and RIP showed excellent agreement, with a mean difference (RIP minus pleth) of -0.5 breaths per minute (limits of agreement -3.4 to +2.3). 52% of 1 min epochs contained 10 s or more of pleth artefact. At 1 hour after BT, children who subsequently required intravenous bronchodilators had significantly higher RR (median (IQR) 63 (62-66) vs 43 (37-51) breaths per minute) than those who did not, but their heart rate and oxygen saturation were similar. Children with RR ≥55 per minute spent longer in hospital: median (IQR) 30 (22-45) vs 10 (7-21) hours. All children who subsequently required hospital admission had PP-analogous pleth waveforms 1 hour after BT.

CONCLUSION

RR can be reliably measured and PP detected from the pulse oximeter pleth trace in children with acute wheeze and both markers predict clinical outcome.

TRIAL REGISTRATION NUMBER

UKCRN15742.

The relationship of early-life household air pollution with childhood asthma and lung function

The increase in childhood asthma over the past few decades has made it an important public health issue. Poor lung function growth associated with some phenotypes of asthma compounds its long-term impact on the individual. Exposure to early-life household risk factors is believed to be linked with respiratory health while infants' lungs are still developing. This review summarises epidemiological studies and mechanistic evidence focusing on the detrimental effects of early-life household air exposures on the respiratory health of children, in particular effects on asthma and lung function. Many early-life household air exposures, including tobacco smoke, gases from heating and cooking, mould/dampness and cleaning products are associated with childhood asthma development and lung function growth. These exposures may alter structural and mechanical characteristics of infants' lungs and contribute to deficits in later life. In addition, some risk factors, including tobacco smoke and cleaning products, can transmit effects across generations to increase the risk of asthma in subsequent generations. This review supports the hypothesis that risks of asthma and accelerated lung ageing are established in early life. The timing of exposure may be critical in the pathogenesis of respiratory diseases, in terms of future risk of asthma and reduced lung function in adults.

Enigma variations: The multi-faceted problems of pre-school wheeze

Numerous publications on wheezing disorders in children younger than 6 years have appeared in the medical literature over the last decades with the aim of shedding light on the mechanistic pathways (endotypes) and treatment. Nevertheless, there is yet no consensus as to the appropriate way to manage preschool wheeze mainly because of the lack of a clear definition of "preschool asthma" and the paucity of scientific evidence concerning its underlying endotypes. A symptom-based approach is inadequate since the human airway can respond to external stimuli with a limited range of symptoms and signs, including cough and wheeze, and these manifestations represent the final expression of many clinical entities with potentially different pathophysiologies requiring different individualized treatments. Hence, new studies challenge the symptom-based approach and promote the importance of managing the wheezy child based on the "airway phenotype." This will enable the clinician to identify not only the child with a serious underlying pathology (e.g., a structural airway disorder or immunodeficiency) who is in need of prompt and specific treatment but also increase the specificity of treatment for the child with symptoms suggestive of an "asthma" syndrome. In the latter case, focus should be given to the identification of treatable traits. This review summarizes the current understanding in management of preschool wheezing and highlights the unmet need for further research.

Global burden of asthma associated with high body mass index from 1990 to 2019

BACKGROUND

High body mass index (BMI) plays a key role in the progression of asthma and asthma related to high BMI resulted in a high burden of disease globally.

OBJECTIVE

This study aimed to explore the geographical and temporal trends in the global burden of asthma associated with high BMI from 1990 to 2019.

METHODS

This is a retrospective analysis with data based on the Global Burden of Disease Study 2019 database. The deaths, disability-adjusted life-years (DALYs), age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) were estimated according to sex, age and sociodemographic indexes (SDI) levels. Estimated annual percentage change (EAPC) was used to evaluate the variation trends of ASMR and ASDR from 1990 to 2019.

RESULTS

In 2019, the number of global asthma deaths and DALYs related to high BMI increased by 69.69% and 63.91% respectively compared with 1990, among which more deaths and DALYs occurred in females. The corresponding ASMR and ASDR showed a slightly decreasing tendency globally. South Asia accounted for the highest number of deaths and DALYs, with India ranked first worldwide in 2019. The number of deaths and DALYs mainly appeared in individuals 60-79 years old and 55-69 years old respectively from 1990 to 2019. The heaviest burden existed in the low-middle SDI region.

CONCLUSION

The global asthma burden associated with obesity increased in absolute value but the standardized burden decreased slightly. Large variations existed in the high BMI-related asthma burdens among sexes, ages and regions.

Management of Preschool Wheezing: Guideline from the Emilia-Romagna Asthma (ERA) Study Group

Preschool wheezing should be considered an umbrella term for distinctive diseases with different observable and measurable phenotypes. Despite many efforts, there is a large gap in knowledge regarding management of preschool wheezing. In order to fill this lack of knowledge, the aim of these guidelines was to define management of wheezing disorders in preschool children (aged up to 5 years). A multidisciplinary panel of experts of the Emilia-Romagna Region, Italy, addressed twelve different key questions regarding the management of preschool wheezing. Clinical questions have been formulated by the expert panel using the PICO format (Patients, Intervention, Comparison, Outcomes) and systematic reviews have been conducted on PubMed to answer these specific questions, with the aim of formulating recommendations. The GRADE approach has been used for each selected paper, to assess the quality of the evidence and the degree of recommendations. These guidelines represent, in our opinion, the most complete and up-to-date collection of recommendations on preschool wheezing to guide pediatricians in the management of their patients, standardizing approaches. Undoubtedly, more research is needed to find objective biomarkers and understand underlying mechanisms to assess phenotype and endotype and to personalize targeted treatment.

Sex differences in febrile children with respiratory symptoms attending European emergency departments: An observational multicenter study

Objective

To assess sex differences in presentation and management of febrile children with respiratory symptoms attending European Emergency Departments.

Design and setting

An observational study in twelve Emergency Departments in eight European countries.

Patients

Previously healthy children aged 0–<18 years with fever (≥ 38°C) at the Emergency Department or in the consecutive three days before Emergency Department visit and respiratory symptoms were included.

Main outcome measures

The main outcomes were patient characteristics and management defined as diagnostic tests, treatment and admission. Descriptive statistics were used for patient characteristics and management stratified by sex. Multivariable logistic regression analyses were performed for the association between sex and management with adjustment for age, disease severity and Emergency Department. Additionally, subgroup analyses were performed in children with upper and lower respiratory tract infections and in children below five years.

Results

We included 19,781 febrile children with respiratory symptoms. The majority were boys (54%), aged 1–5 years (58%) and triaged as low urgent (67%). Girls presented less frequently with tachypnea (15% vs 16%, p = 0.002) and increased work of breathing (8% vs 12%, p<0.001) compared with boys. Girls received less inhalation medication than boys (aOR 0.82, 95% CI 0.74–0.90), but received antibiotic treatment more frequently than boys (aOR 1.09, 95% CI 1.02–1.15), which is associated with a higher prevalence of urinary tract infections. Amongst children with a lower respiratory tract infection and children below five years girls received less inhalation medication than boys (aOR 0.77, 95% CI 0.66–0.89; aOR 0.80, 95% CI 0.72–0.90).

Conclusions

Sex differences concerning presentation and management are present in previously healthy febrile children with respiratory symptoms presenting to the Emergency Department. Future research should focus on whether these differences are related to clinicians’ attitudes, differences in clinical symptoms at the time of presentation and disease severity.

Addition of a nutraceutical to montelukast or inhaled steroid in the treatment of wheezing during COVID-19 pandemic: a multicenter, open-label, randomized controlled trial

Background and aim Recurrent wheezing is often triggered by viral respiratory infections. The aims of our study were: i) to evaluate whether the addition of a nutraceutical (Leucodif®), could improve the efficacy of montelukast or inhaled steroids (ICS) compared to the single treatment; ii) to verify whether a treatment is more effective than another. Our study was biased by the COVID-19 pandemic, which resulted in a lockdown of almost two months in Italy. Methods The multicenter, open-label study enrolled 84 children aged 2-6 years diagnosed with recurrent wheezing and randomized them into four treatment arms for three months: ICS treatment; ii) montelukast; iii) montelukast + Leucodif; iv) ICS + Leucodif. Children were assessed at baseline and after one, two, and three months of treatment using the TRACK score for both the caregiver and the physician. Results Out of the 84 patients, 18 patients received ICS therapy, 22 patients ICS + Leucodif, 24 patients montelukast, and 20 patients montelukast + Leucodif. All four treatments resulted in a significant reduction in symptoms with no differences among the various groups. Conclusions Our study demonstrates that montelukast therapy appears to be equally effective as ICS therapy and that the addition of the nutraceutical Leucodif does not appear to improve the treatment outcome. However, in our opinion our study was strongly influenced and biased by the lockdown due to the COVID-19 pandemic, which inherently resulted in reduced exposure to the viruses that commonly cause respiratory infections in children.