Age-related changes in childhood wheezing characteristics: A whole population study

External validation of the Predicting Asthma Risk in Children tool in a clinical cohort

INTRODUCTION

The Predicting Asthma Risk in Children (PARC) tool uses questionnaire-based respiratory symptoms collected from preschool children to predict asthma risk 5 years later. The tool was developed and validated in population cohorts but not validated using a clinical cohort. We aimed to externally validate the PARC tool in a pediatric pulmonology clinic setting.

METHODS

The Swiss Paediatric Airway Cohort (SPAC) is a prospective cohort of children seen in pediatric pulmonology clinics across Switzerland. We included children aged 1-6 years with cough or wheeze at baseline who completed the 2-year follow-up questionnaire. The outcome was defined as current wheeze plus use of asthma medication. We assessed performance using: sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV), area under the curve (AUC), scaled Brier's score, and Nagelkerke's R² scores. We compared performance in SPAC to that in the original population, the Leicester Respiratory Cohort (LRC).

RESULTS

Among 346 children included, 125 (36%) reported the outcome after 2 years. At a PARC score of 4: sensitivity was higher (95% vs. 79%), specificity lower (14% vs. 57%), and NPV and PPV comparable (0.84 vs. 0.87 and 0.37 vs. 0.42) in SPAC versus LRC. AUC (0.71 vs. 0.78), R² (0.18 vs. 0.28) and Brier's scores (0.13 vs. 0.22) were lower in SPAC.

CONCLUSIONS

The PARC tool shows some clinical utility, particularly for ruling out the development of asthma in young children, but performance limitations highlight the need for new prediction tools to be developed specifically for the clinical setting.

The course of specific self-reported exercise-induced airway symptoms in adolescents with and without asthma

Airway symptoms in conjunction with exercise can take on many forms and can have several contributory factors such as exercise-induced bronchoconstriction (EIB), exercise-induced laryngeal obstruction or hyperventilation [1]. Previous longitudinal studies on self-reported exercise-induced airway symptoms among adolescents have primarily studied single symptoms, focusing on dyspnoea or wheeze, often as a way to investigate the prevalence of asthma [2, 3]. To the best of our knowledge, there are, as yet, no population-based studies investigating the difference between adolescents with and without current asthma regarding the development of different specific exercise-induced airway symptoms. Therefore, we studied the natural course of self-reported exercise-induced dyspnoea, throat tightness, wheeze, chest tightness, cough, stridor and hoarseness over a 5-year period among adolescents with and without current asthma.

In a general population, the prevalence of exercise-induced cough, dyspnoea, throat and chest tightness, wheeze, and stridor increases from adolescence to young adulthood among individuals without asthma in contrast to individuals with asthmahttps://bit.ly/3hR57OX

Clinical Profile of Episodic Wheezing and Multiple Trigger Wheezing in Preschool Children: A Cross-Sectional Study

The objectives of our study were to identify the relative frequency of episodic viral wheeze (EVW) and multiple trigger wheeze (MTW) in preschool children of 1 to 5 years of age with recurrent wheezing and to compare the relevant clinical and sociodemographic parameters in the above phenotypes. This cross-sectional study included 165 children aged 1 to 5 years with recurrent wheeze. Participants were categorized into EVW and MTW based on history according to European Respiratory Society Task Force recommendations 2008. Symptom control was assessed by Global Initiative for Asthma guidelines 2015. Of the total participants, EVW was seen in 55% and MTW in 45%. Children with MTW were significantly older than those with EVW, more atopic, and had higher eosinophil counts. The dominant phenotype seen in our study was EVW. The absence of ocular/nasal allergy and exclusive breastfeeding predicted well-controlled symptoms in EVW and in all preschool wheezers, respectively.

Aeroallergen sensitization in Lebanese asthmatic children: the results of a cohort national study

Atopic asthma is characterized by the presence of sensitization to common aeroallergens, which tends to have a worse prognosis than non-atopic asthma. The objectives were to determine the prevalence of aeroallergens sensitization in the Lebanese pediatric asthmatic population and determine the relationship between allergens sensitization (indoor and outdoor) and age, area of residence and altitude. A sample, consisting of 919 asthmatic children (aged 1 to 18 years, from 2010 until 2017), underwent skin prick testing (SPT) with 21 common allergens: 5 grasses (cocksfoot, sweet vernal-grass, rye-grass, meadow grass, timothy), Parietaria, olive, Dermatophagoides pteronyssinus and Dermatophagoides farina (DP-DF), dog and cat dander, Alternaria longipens, Aspergillus fumigatus and nidulans, Cupressaceae, pine, German cockroach, and 4 cereals (oat, wheat, barley, maize). Seven hundred fifty-two patients had positive SPT. The distribution of sensitization was as follows: DP-DF 59%; 5 grasses 34%; 4 cereals 33.9%; cat 29.9%; Alternaria 27.9%; Parietaria 23%; dog 21.9%; olive 20.5%; Aspergillus mix 18.6%; Cupressaceae 18.2%; pine 17%; cockroach 15.3%. House dust mites sensitization was frequent at lower altitude (< 900 m) (56.3%) and in the whole country (a median prevalence of 53.05%) except for the Beqaa region (negative HDM in 82.4%). Non-atopic asthma was more frequent in early childhood (40.5% at 1-4 years vs 11.2% at 11-18 years). The sensitization rate increased with age, starting at 5 years. Higher age (aOR = 1.24) and altitude less than 900 m compared with ≥ 900 m (aOR = 2.03) were significantly associated with the presence of aeroallergens in children. House dust mites and grasses are the most common allergens in Lebanese asthmatic children. Non-atopic asthma is more frequent at early age. Lebanese children with asthma showed a polysensitized pattern starting at 5 years.

Special Considerations in Preschool Age

The diagnosis of asthma can be particularly difficult in young children, in whom wheezing is not always synonym with asthma. It is also difficult to predict which preschool children with wheeze will go on to be true asthmatics. In this chapter, we will characterize preschool wheezing and asthma and discuss early risk factors for the development of severe asthma. We will also review risk factors for severe acute wheezing in young children. Finally, we will describe the natural history and prognosis of wheezing and some of the attempts at early identification of children who will develop severe asthma.

In vitro drug delivery performance of five valved holding chambers with and without facemasks

BACKGROUND

Valved holding chambers (VHCs) are essential for efficient pulmonary delivery of inhaled medication in preschool children. The numerous devices in the market vary in material, aerodynamic characteristics, volume, valve properties, and mask design. Drug delivery is affected by the VHC characteristics as well as by the age and breathing pattern of the child.

METHODS

We measured the drug delivery efficacy of five VHCs widely available in the market, evaluated the effect of facemasks and tested the differences between manufacturing lots. A breathing simulator was used to mimic normal (respiratory rate [RR] 25/minute and tidal volume (V_T ) 200 mL) and obstructive (RR 50/minute and V_T 50 mL) breathing of infants and toddlers.

RESULTS

Salbutamol output was significantly higher with a normal breathing pattern compared to the obstructive breathing pattern in most VHCs. Without masks, the differences in the median in vitro filter doses of salbutamol were mainly from 2 to 10-fold among different types of VHCs. With masks, there was a greater than 20-fold difference in drug delivery capacity between the most and least effective devices. Most VHCs had a notable variation of performance between individual devices from different lots within the same brand.

CONCLUSIONS

There was an extreme variation in the salbutamol delivery performance among different types of VHCs for both normal and obstructive pediatric breathing patterns with and without masks. This magnitude of performance variability can have significant and unpredictable clinical implications.

Do clinical investigations predict long-term wheeze? A follow-up of pediatric respiratory outpatients

INTRODUCTION

The contribution of clinical investigations to prediction of long-term outcomes of children investigated for asthma is unclear.

AIM

We performed a broad range of clinical tests and investigated whether they helped to predict long-term wheeze among children referred for evaluation of possible asthma.

METHODS

We studied children aged 6 to 16 years referred to two Swiss pulmonary outpatient clinics with a history of wheeze, dyspnea, or cough in 2007. The initial assessment included spirometry, fractional exhaled nitric oxide, skin prick tests, and bronchial provocation tests by exercise, methacholine, and mannitol. Respiratory symptoms were assessed with questionnaires at baseline and at follow-up 7 years later. Associations between baseline factors and wheeze at follow-up were investigated by logistic regression.

RESULTS

At baseline, 111 children were examined in 2007. After 7 years, 85 (77%) completed the follow-up questionnaire, among whom 61 (72%) had wheeze at baseline, while at follow-up 39 (46%) reported wheeze. Adjusting for age and sex, the following characteristics predicted wheeze at adolescence: wheeze triggered by pets (odds ratio, 4.2; 95% CI, 1.2-14.8), pollen (2.8, 1.1-7.0), and exercise (3.1, 1.2-8.0). Of the clinical tests, only a positive exercise test (3.2, 1.1-9.7) predicted wheeze at adolescence.

CONCLUSION

Reported exercise-induced wheeze and wheeze triggered by pets or pollen were important predictors of wheeze persistence into adolescence. None of the clinical tests predicted wheeze more strongly than reported symptoms. Clinical tests might be important for asthma diagnosis but medical history is more helpful in predicting prognosis in children referred for asthma.

Risk factors and prognosis of recurrent wheezing in Chinese young children: a prospective cohort study

Background

Nearly all the investigations into the risk factors for wheezing and asthma were conducted in developed countries with a high prevalence rate of asthma and allergy, but the studies in developing countries are limited. In this study, we aimed to investigate the risk factors for different wheezing phenotypes in Chinese young children and to explore the prognosis of recurrent wheezing.

Methods

This cohort study contained the recruitment stage and the follow-up stage conducted by phone questionnaire survey. According to the information collected at the follow-up for wheezing episodes and remission age, our cohort was divided into transient wheezing, persistent wheezing and late-onset wheezing. The wheezing symptoms and potential risk factors were compared between these three wheezing groups.

Results

From the initial 109 participants, 78.0% completed the follow-up survey. The frequency of current wheezing at followup was significantly reduced in all three groups compared to the recruitment stage (p < 0.01). We observe a trend that the rhinovirus (RV) and respiratory syncytial virus (RSV) infection rates were higher in the persistent wheezing group, and the overall infection rates appear to be the lowest in late-onset wheezing group at recruitment. At follow-up stage, the rates of rhinitis ever and current rhinitis were both higher in the persistent wheezing (63.0%, 50.0%) and late-onset wheezing groups (88.2%, 58.8%), compared to the transient wheezing group (14.3%, 14.3%). The incidence of current wheezing episodes increased cumulatively if the participant had concomitant risk factors of rhinitis ever, aeroallergens sensitization at recruitment, either alone or together with previous RV infection at the time of recruitment.

Conclusion

While the incidence of wheezing declined overall with age, but in addition to transient wheezers, additional subsets of children manifest persistent wheeze or late onset wheeze, and moreover the risk factors for wheezing display phenotypic variability between these subgroups. Rhinitis ever and aeroallergens sensitization, either alone or together with previous RV infection, were the most significant predictors for persistent wheezing in children in an eastern environment, such as in China.

Increased prevalence of exercise-induced airway symptoms - A five-year follow-up from adolescence to young adulthood

BACKGROUND

Exercise-induced airway symptoms are common in adolescents. Little is known about the development of symptoms from adolescence to early adulthood. Therefore, we studied the prevalence, incidence, and remission of exercise-induced airway symptoms (including wheeze, cough, chest and throat tightness, hoarseness, and stridor) in adolescents, over a five-year period.

METHODS

In 2011, all adolescents aged 12-13 years in Uppsala (n = 3 838) were invited to answer a questionnaire on exercise-induced airway symptoms. All responding adolescents (n = 2 309) were invited to answer the same questionnaire again after five years. In total, 1 002 adolescents responded (43.4%).

RESULTS

The prevalence of exercise-induced airway symptoms increased from 25% at baseline to 49% at follow-up (p < 0.001). More females than males reported symptoms at both time points. The incidence of airway symptoms was 42.2%, with no sex differences. More males than females reported symptom remission (20.2 vs. 10.7%, p < 0.001). Females reported a higher asthma prevalence at follow-up than at baseline (7.6 vs. 15.2%), while males did not (10.9 vs. 8.0%), leading to a sex difference in prevalence at follow-up (p < 0.001). Smoking and baseline respiratory symptoms were associated with an increased risk of reporting symptoms at follow-up.

CONCLUSIONS

A twofold increase in the prevalence of exercise-induced airway symptoms over a five-year period was found in this cohort. Females were more likely to report symptoms at both time points. Knowledge of these age-related changes in symptoms and their association to female gender is useful for future studies and healthcare providers.

High-Dose Vitamin D Supplementation Does Not Prevent Allergic Sensitization of Infants

OBJECTIVE

To investigate the effect of vitamin D supplementation dose on allergic sensitization and allergic diseases in infants, and to evaluate whether vitamin D status in pregnancy and at birth are associated with infant allergy outcomes.

STUDY DESIGN

Altogether, 975 infants participated in a randomized, controlled trial of daily vitamin D supplementation of 10 μg (400 IU) or 30 μg (1200 IU) from the age of 2 weeks. At 12 months of age, food and aeroallergen IgE antibodies were measured, and the occurrence of allergic diseases and wheezing were evaluated.

RESULTS

We found no differences between the vitamin D supplementation groups in food (OR, 0.98; 95% CI, 0.66-1.46) or aeroallergen sensitization at 12 months (OR, 0.76; 95% CI,0.34-1.71). Allergic diseases or wheezing did not differ between groups, except for milk allergy which occurred more often in infants administered 30 μg vitamin D compared with the 10 μg dose (OR, 2.23; 95% CI, 1.00-4.96). Infants with high cord blood 25-hydroxyvitamin D (≥100 nmol/L) had a higher risk of food allergen sensitization compared with those with lower 25(OH)D concentration (75-99.9 nmol/L; OR, 2.00; 95% CI, 1.19-3.39).

CONCLUSIONS

High-dose vitamin D supplementation did not prevent allergic sensitization, allergic diseases, or wheezing during the first year of life. In contrast, we observed an increased risk of milk allergy in infants randomized to higher vitamin D supplementation, and an increased risk of allergic sensitization in infants with high cord blood vitamin D status, indicating a possible adverse effect of high concentrations of vitamin D.

Valved holding chamber drug delivery is dependent on breathing pattern and device design

Small children with airway obstruction breathe with very low tidal volumes (V_T) and high respiratory rates (RRs). These extreme respiratory patterns affect drug delivery unpredictably through valved holding chambers (VHCs).

We compared in an in vitro study the effectiveness of two VHCs, one small (140 mL, Optichamber Diamond) and one large (350 mL, Babyhaler) without facemasks, to deliver salbutamol to filters positioned between the VHC mouthpieces and a breathing simulator. Different tidal volumes (from 30 mL to 200 mL) and RRs (25·min^-1 and 50·min^-1) were applied through a breathing simulator.

The amount of salbutamol delivered increased with increasing V_T in both VHCs for both RRs (ρ>0.87 and p<0.001 for both devices at both rates). The effect of RR was not as evident, but drug delivery tended to be higher at the higher rate. Drug delivery was significantly higher through the Optichamber Diamond as compared with the Babyhaler at every combination of RR and V_T up to a 12-fold difference.

We found marked differences in salbutamol delivery between the Babyhaler and Optichamber Diamond VHCs. The delivered dose of salbutamol increased with increasing V_T and RR with both VHCs but with differences related to valve dead spaces. Instead of considering all VHCs equal in clinical paediatric practice, each device should be tested in vitro with respiratory patterns relevant to small children with respiratory difficulties.

Children with respiratory problems are treated with inhaled drugs given via valved holding chambers (VHCs). Efficacy can vary up to 12-fold between devices. The effectiveness of VHCs should be tested in all age groups with different respiratory patterns.http://ow.ly/2Aca30mT2Pa

The Swiss Paediatric Airway Cohort (SPAC)

Chronic respiratory symptoms, such as cough, wheeze and dyspnoea, are common in children; however, most research has, with the exception of a few large-scale clinical cohort studies, been performed in the general population or in small, highly-selected samples.

The Swiss Paediatric Airway Cohort (SPAC) is a national, prospective clinical cohort of children and adolescents who visit physicians for recurrent conditions, such as wheeze and cough, and exercise-related respiratory problems. The SPAC is an observational study and baseline assessment includes standardised questionnaires for families and data extracted from hospital records, including results of clinically indicated investigations, diagnoses and treatments. Outcomes are assessed through annual questionnaires, monthly symptom reporting via mobile phone and follow-up visits.

The SPAC will address important questions about clinical phenotypes, diagnosis, treatment, and the short- and long-term prognosis of common respiratory problems in children. The cohort currently consists of 347 patients from four major hospitals (Bern, Zurich, Basel and Lucerne), with 70–80 additional patients joining each month. More centres will join and the target sample size is a minimum of 3000 patients.

The SPAC will provide real-life data on children visiting the Swiss healthcare system for common respiratory problems and will provide a research platform for health services research and nested clinical and translational studies.

The Swiss Paediatric Airway Cohort (SPAC) is a unique research platform for common respiratory problems in childrenhttp://ow.ly/Y1v030lDnji

Antibiotics in the first week of life were associated with atopic asthma at 12 years of age

Aim

This study explored the prevalence of atopic and nonatopic asthma in 12‐year‐old children and whether they were associated with different risk factors. In particular, we wanted to analyse whether receiving antibiotics during the first week of life was associated with asthma at that age.

Methods

Data were obtained from a longitudinal cohort study of 5654 Swedish children born in 2003. The parents answered questionnaires from the age of six months until 12 years. The response rate at 12 years was 3637/4777 (76%).

Results

At 12 years, 6.4% reported current doctor‐diagnosed asthma. Treatment with antibiotics during the first week of life was associated with an increased risk of atopic asthma, with an adjusted odds ratio of 2.2 and 95% confidence interval of 1.2–4.2. Being born small for gestational age was associated with an increased risk of nonatopic asthma, with an adjusted odds ratio of 3.8 and 95% confidence interval of 1.1–13.7. Asthma that only occurred with colds was reported by 28%.

Conclusion

Antibiotic treatment during the first week of life was associated with an increased risk of atopic asthma at 12 years, suggesting an immune‐mediated effect. Being born small for gestational age increased the risk of nonatopic asthma.

The highs and lows of wheezing: A review of the most popular adventitious lung sound

Wheezing is the most widely reported adventitious lung sound in the English language. It is recognized by health professionals as well as by lay people, although often with a different meaning. Wheezing is an indicator of airway obstruction and therefore of interest particularly for the assessment of young children and in other situations where objective documentation of lung function is not generally available. This review summarizes our current understanding of mechanisms producing wheeze, its subjective perception and description, its objective measurement, and visualization, and its relevance in clinical practice.