Difficult to control asthma in children

Genetic Variations on Chromosome 6p21 Are Associated with Asthma Risk and Disease Severity: A Case-Control Study from Pakistan

BACKGROUND

Genetic factors play a role in asthma severity. However, low- and middle-income countries have minimal contribution to genomic asthma research. The current study investigates the influence of an important genetic asthma region (6p21) on severe asthma in a cohort of asthmatics in Pakistan.

MATERIALS AND METHODS

In this case-control study, mild to severe asthmatic patients (n = 255) and controls (n = 260) were enrolled from Lahore, Pakistan. Blood samples were collected, and genomic DNA was extracted for the genotyping of 11 single nucleotide polymorphisms located in the 6p21 region. Severe asthma was defined based on the defined daily dose of inhaled corticosteroids equivalent to 200 mcg of beclomethasone dipropionate (as per the global initiative for asthma guidelines). An additive genetic model was followed to find the associations between these variants and the outcome. Univariate and multivariate logistic regression, adjusted for confounders, was performed. Odds ratio (OR), 95% confidence interval (95% CI), p-value, and q-values after FDR adjustment were estimated.

RESULTS

The genetic variants rs3025028, rs987870, and rs3025039 showed strong associations with the incidence of asthma with odds ratios of 1.58, 1.62, and 2.70 (95% CI = 1.16-2.16, 1.15-2.30, and 1.40-5.39, respectively). Further stratification analysis to study the risk of severe asthma also revealed markedly significant associations for rs3025020 and rs1799964 (OR = 2.28 and 2.99; 95% CI = 1.39-3.86 and 1.75-5.33, respectively). However, the SNPs rs2070600, rs987870, and rs3025039 also showed a significant relationship with the severity (OR = 2.34, 1.75, and 2.72; 95% CI = 1.02-5.97, 1.07-2.98, and 1.11-7.71, respectively), but FDR-adjusted q-values were insignificant (0.10, 0.07, and 0.07, respectively).

CONCLUSIONS

The 6p21 region variants rs3025028, rs987870, and rs3025039 are associated with the incidence, whereas rs3025020 and rs1799964 are associated with the risk of more severe asthma in the Pakistani population.

The Extra Cost Due to Non-Adherence to Inhaled Treatments in Adolescents with Mild-to-Moderate Persistent Asthma

Bronchial asthma has a high socio-economic impact in Western countries. Low adherence to prescribed inhalation treatments contributes to poor asthma control and the higher utilization of healthcare resources. Although adolescents usually do not comply with long-term inhaled treatments prescribed on a regular basis, the related economic consequences still are poorly investigated in Italy.

AIM

A 12-month estimation of the economic impact of non-adherence to inhalation treatments in adolescents with mild-to-moderate atopic asthma.

METHODS

Non-smoking adolescents aged 12-19 years, without any significant comorbidity, prescribed with inhaled cortico-steroids (ICS) or ICS/long-acting beta(2)-adrenergics (LABA) via dry powder inhalers (DPIs) on a regular basis were automatically selected from the institutional database. Spirometric lung function, clinical outcomes, and pharmacological information were collected. The adolescents' adherence to their prescribed regimen was calculated monthly. Adolescents were divided in two sub-groups based on their adherence to prescriptions: ≤70% (not adherent) or >70% (adherent), and statistically compared (Wilcoxon test, assuming p < 0.05).

RESULTS

Overall, 155 adolescents fulfilled the inclusion criteria (males, 49.0%; mean age, 15.6 years ± 2.9 SD; mean BMI, 19.1 ± 1.3 SD). Mean values of lung function were: FEV1 = 84.9% pred. ± 14.8 SD, FEV1/FVC = 87.9 ± 12.5 SD; MMEF = 74.8% pred. ± 15.1 SD and V25 = 68.4% pred. ± 14.9 SD. ICS had been prescribed in 57.4% of subjects and ICS/LABA in 42.6%. Mean adherence to original prescriptions was 46.6% ± 9.2 SD in non-adherent and 80.3% ± 6.6 SD in adherent adolescents, respectively (p < 0.001). The mean rates of hospitalizations, exacerbations, and GP visits; the average duration of absenteeism; the frequency of systemic steroids and antibiotics courses needed over the study period were significantly and substantially lower in adolescents adherent to prescriptions (all p < 0.001). The mean total annual extra cost calculated in the two sub-groups was EUR 705.8 ± 420.9 SD in non-adherent adolescents and EUR 192.1 ± 68.1 SD in adherent adolescents, respectively (p < 0.001), which was 3.7 times higher than in non-adherent adolescents.

CONCLUSIONS

In adolescents, the clinical control of mild-to-moderate atopic asthma is directly and strictly related to the degree of adherence to prescribed inhalation therapies. All clinical and economic outcomes prove dramatically poor when adherence is low, and treatable asthma can be frequently mistaken for refractory asthma in these cases. Adolescents' non-adherence impacts the burden of the disease quite substantially. Much more effective strategies centered specifically on adolescents' asthma are needed.

Effects of Adherence to Once-Daily Treatment on Lung Function, Bronchial Hyperreactivity and Health Outcomes in Adolescents with Mild-to-Moderate Asthmoka: A Twelve-Month Survey

Adolescents with asthma are usually insufficiently adherent to regular inhalation treatments, thus limiting their effectiveness. The aim of this study is to investigate the role of adherence to single-inhaler long-acting LABA/ICS dry-powder combination o.d. in affecting lung function, bronchial hyperreactivity, and health outcomes over a twelve-month survey of a group of non-smoking adolescents with mild to moderate asthma. Methods: Age, gender, BMI and atopy, forced expiratory volume in 1 s (FEV1), maximum mid-expiratory flow (MMEF), and maximum expiratory flow at 25% of lung filling (MEF25) were assessed via a Boolean selection process from the institutional database at recruitment, as well as after 6 and 12 months, together with the incidence of exacerbation, school days that were taken off, GP and specialist visits, and systemic steroid and/or antibiotic courses. Adherence was checked monthly via a direct telephone call. Statistics were calculated with an ANOVA trend analysis, assuming p < 0.05. Results: Two well-matched sample groups of 54 subjects each were obtained. The mean annual adherence to treatment ranged from 48.2% doses ± 10.9 sd to 79.3% doses ± 8.8 sd (p < 0.001), regardless of age and gender. Only adolescents that adhered to the o.d. ICS/LABA inhalation regimen progressively achieved complete control of all lung function parameters (FEV1: 0.001; MMEF: p < 0.002; MEF25 < 0.001; <0.001), minimized their bronchial hyperreactivity (p < 0.001), and optimized all health outcomes (p < 0.001—p < 0.002) over the survey duration. Discussion: A good adherence to treatment is essential for asthma management, particularly in young patients. Factors that are totally independent of the complexity of the therapeutic regimen adopted (namely, only a once-daily inhalation in the present survey) probably represent the major reasons limiting the adolescents’ adherence. Cultural, educational, behavioral, and psychological factors are frequently involved, are difficult to control, and can present barriers to adolescents’ asthma management. Further studies aiming to deeply understand and possibly remove the reasons for such adolescents’ attitudes are needed, in cooperation with actions oriented in this direction by families, educators, and health professionals.

Electronic reminders and rewards to improve adherence to inhaled asthma treatment in adolescents: a non-randomised feasibility study in tertiary care

OBJECTIVE

To test the feasibility and acceptability of a short-term reminder and incentives intervention in adolescents with low adherence to asthma medications.

METHODS

Mixed-methods feasibility study in a tertiary care clinic. Adolescents recruited to a 24-week programme with three 8-weekly visits, receiving electronic reminders to prompt inhaled corticosteroid (ICS) inhalation through a mobile app coupled with electronic monitoring devices (EMD). From the second visit, monetary incentives based on adherence of ICS inhalation: £1 per dose, maximum £2 /day, up to £112/study, collected as gift cards at the third visit. End of study interviews and questionnaires assessing perceptions of asthma and ICS, analysed using the Perceptions and Practicalities Framework.

PARTICIPANTS

Adolescents (11-18 years) with documented low ICS adherence (<80% by EMD), and poor asthma control at the first clinic visit.

RESULTS

10 out of 12 adolescents approached were recruited (7 males, 3 females, 12-16 years). Eight participants provided adherence measures up to the fourth visits and received rewards. Mean study duration was 281 days, with 7/10 participants unable to attend their fourth visit due to COVID-19 lockdown. Only 3/10 participants managed to pair the app/EMD up to the fourth visit, which was associated with improved ICS adherence (from 0.51, SD 0.07 to 0.86, SD 0.05). Adherence did not change in adolescents unable to pair the app/EMD. The intervention was acceptable to participants and parents/guardians. Exit interviews showed that participants welcomed reminders and incentives, though expressed frustration with app/EMD technological difficulties. Participants stated the intervention helped through reminding ICS doses, promoting self-monitoring and increasing motivation to take inhalers.

CONCLUSIONS

An intervention using electronic reminders and incentives through an app coupled with an EMD was feasible and acceptable to adolescents with asthma. A pilot randomised controlled trial is warranted to better estimate the effect size on adherence, with improved technical support for the EMD.

Role of NEAT1/MiR-9-5p/SLC26A2 Pathway on Human Airway Smooth Muscle Cell

PURPOSE

Asthma is a serious inflammatory disease of the respiratory system in which airway smooth muscle cells (ASMCs) play a key role. This study aimed to investigate the expression of SLC26A2 in human ASMCs (HASMCs) and the regulatory mechanism of SLC26A2 in the proliferation and inflammatory factor production of HASMCs.

MATERIALS AND METHODS

We obtained the asthma-associated differential mRNA SLC26A2 by bioinformatics analysis in childhood acute asthma samples. To investigate its role in airway inflammation and airway remodeling, we treated HASMCs with platelet-derived growth factor (PDGF) in an in vitro model and determined SLC26A2 expression in cells using western blotting. Cell proliferation was detected by MTT and EdU assays, and cell contractile phenotype marker proteins were measured. Cell migration and production of inflammatory factors were determined by Transwell and ELISA assays. Additionally, the upstream regulatory miRNA and LncRNA of SLC26A2 were identified by bioinformatics, luciferase reporter gene, and RIP analyses.

RESULTS

SLC26A2 was significantly upregulated in bioinformatics analysis of pediatric asthma-related sample. PDGF treatment up-regulated SLC26A2 expression in HASMCs, whereas the knockdown of SLC26A2 inhibited PDGF-stimulated proliferation, migration, and production of inflammatory factors, and enhanced the expression of cell contractile phenotype marker proteins in HASMCs. Luciferase reporter and RIP experiments validated that NEAT1 targeted miR-9-5p to regulate SLC26A2, thereby influencing the biological function of PDGF-induced HASMCs.

CONCLUSION

These findings indicate that NEAT1-mediated miR-9-5p targeting of SLC26A2 inhibits the PDGF-induced proliferation and production of inflammatory factors in HASMCs. These findings highlight potential therapeutic targets for asthma and airway inflammation.

Association of Childhood Atopic Dermatitis With a Higher Risk of Health Care Utilization and Drug Use for Asthma: A Nationwide Cohort Study

BACKGROUND

Overwhelming evidence supports a causal relationship between occurrence of asthma and atopic dermatitis (AD).

OBJECTIVE

The aims of the study were to determine the incidence of asthma in children with AD and to examine the health care utilization and drug use for asthma in children with AD.

METHODS

Children with hospital-diagnosed AD (cases) were matched with individuals from the background population (controls) in a 1:4 ratio.

RESULTS

In the final cohort (18,625 cases and 74,500 controls), the incident cases of asthma were 4203 among AD cases and 5298 in controls, corresponding to incidence rates of 34 and 9 in cases and controls per 1000 person-years, respectively (hazard ratio [HR] = 3.82, 95% confidence interval [CI] = 3.65-4.00). During the 1-year follow-up period from asthma diagnosis, children with concomitant AD had a significantly higher risk of hospital admission (HR = 1.97, 95% CI = 1.63-2.37), emergency department visits (HR = 1.62, 95% CI = 1.22-2.14), outpatient visits (HR = 1.97, 95% CI = 1.74-2.23), asthma medication (HR = 1.31, 95% CI = 1.27-1.35), and rescue course corticosteroids (HR = 1.74, 95% CI = 1.13-2.69) compared with children with asthma only.

CONCLUSIONS

The risk of being diagnosed with asthma was higher in children with AD. Risk of health care utilization and drug use for asthma was higher in children with both AD and asthma compared with asthma only.

Diagnosis and Management of Severe Asthma in Switzerland: Analysis of Survey Results Conducted with Specialists and General Practitioners

BACKGROUND

Severe asthma commonly affects 5-10% of the asthmatic population and accounts for approximately 50% of the overall asthma costs.

OBJECTIVE

This analysis investigated how severe asthma is diagnosed, treated, and managed by specialists and general practitioners (GPs) in Switzerland.

METHODS

Two surveys, one each among specialists (N = 44) and GPs (N = 153), were conducted to understand their self-perception on diagnosis, treatment, and management of severe asthma.

RESULTS

Fifty-five percent of the specialists felt very confident and 43% confident in recognizing the symptoms of severe asthma and diagnosing severe asthma. In contrast, 9% of the GPs were very confident and 59% confident in diagnosing severe asthma. More specific diagnostic tests for severe asthma, like total and specific immunoglobulin E levels and measurement of the fraction of exhaled nitric oxide, were run by specialists (χ2 = 171.4; df = 15, p < 0.001). GPs and specialists were using different measurements to assess severe asthma (χ2 = 385.2; df = 13, p < 0.001) and their prescribing patterns differed significantly (χ2 = 189.8; df = 10, p < 0.001). GPs referred patients with severe asthma if the diagnosis was unclear (24%), if treatment failure occurred (26%), and if the patients were at high risk (41%).

CONCLUSIONS

Oral corticosteroids (OCSs) are considered as background therapy for severe asthma by GPs and specialists. In order to reduce the OCS burden, there is a need to improve the awareness for other add-on therapies. A joint collaboration between GPs and specialists is the key to leverage therapeutic strategies together.

Sociodemographic factors, current asthma and lung function in an urban child population

BACKGROUND

We aimed to assess which sociodemographic factors are associated with current asthma and indicators of lung function in 10-year-old children.

METHODS

We analysed data of 5237 children (Mean age: 9.7, SD: 0.3) from the Generation R Study (2012-2016), a population-based cohort study in the Netherlands. Indicators of sociodemographic factors included parental educational level, net household income, financial difficulties, parental employment status and child ethnic background. Current asthma (yes/no) was defined as ever doctor-diagnosed-asthma combined with wheezing symptoms or asthma-medication use in the past 12 months. Lung function was measured by spirometry and included forced expiratory volume in 1 second (FEV₁ ), forced vital capacity (FVC), FEV₁ /FVC, and forced expiratory flow after exhaling 75% of FVC (FEF₇₅ ). Within-study sex-, height- and age-adjusted lung function measurements' z-scores were converted.

RESULTS

After adjustment for all sociodemographic factors, an independent association was observed between ethnic background with current asthma and lung function. Compared with children with a Dutch background, children with a nonwestern ethnic background had a higher odds of having current asthma (OR: 1.61, 95% CI: 1.02, 2.53), lower FVC z-score (-0.25, 95% CI: -0.35, -0.14), higher FEV₁ /FVC z-score (0.26, 95% CI: 0.14, 0.37) and higher FEF_75% z-score (0.15, 95% CI: 0.04, 0.25).

CONCLUSIONS

Among 10-year-old children, ethnic background was associated with current asthma and lung function after adjusting for a wide range of sociodemographic factors. No associations were found between socioeconomic status indicators and current asthma. Explanations for these associations such as language barriers, suboptimal care or pathophysiological differences require further investigation.

Serelaxin enhances the therapeutic effects of human amnion epithelial cell-derived exosomes in experimental models of lung disease

BACKGROUND AND PURPOSE

There is growing interest in stem cell-derived exosomes for their therapeutic and regenerative benefits given their manufacturing and regulatory advantages over cell-based therapies. As existing fibrosis impedes the viability and efficacy of stem cell/exosome-based strategies for treating chronic diseases, here we tested the effects of the anti-fibrotic drug, serelaxin, on the therapeutic efficacy of human amnion epithelial cell (AEC)-derived exosomes in experimental lung disease.

EXPERIMENTAL APPROACH

Female Balb/c mice were subjected to either the 9.5-week model of ovalbumin and naphthalene (OVA/NA)-induced chronic allergic airway disease (AAD) or 3-week model of bleomycin (BLM)-induced pulmonary fibrosis; then administered increasing concentrations of AEC-exosomes (5 μg or 25μg), with or without serelaxin (0.5mg/kg/day) for 7-days. 1x10⁶ AECs co-administered with serelaxin over the corresponding time-period were included for comparison in both models, as was pirfenidone-treatment of the BLM model. Control groups received saline/corn oil or saline, respectively.

KEY RESULTS

Both experimental models presented with significant tissue inflammation, remodelling, fibrosis and airway/lung dysfunction at the time-points studied. While AEC-exosome (5 μg or 25μg)-administration alone demonstrated some benefits in each model, serelaxin was required for AEC-exosomes (25μg) to rapidly normalise chronic AAD-induced airway fibrosis and airway reactivity, and BLM-induced lung inflammation, epithelial damage and subepithelial/basement membrane fibrosis. Combining serelaxin with AEC-exosomes (25μg) also demonstrated broader protection compared to co-administration of serelaxin with 1x10⁶ AECs or pirfenidone.

CONCLUSIONS AND IMPLICATIONS

Serelaxin enhanced the therapeutic efficacy of AEC-exosomes in treating basement membrane-induced fibrosis and related airway dysfunction.

Severe asthma in children: Evaluation and management

Severe asthma in children is associated with significant morbidity. Children with severe asthma are at increased risk for adverse outcomes including medication-related side effects, life-threatening exacerbations, and impaired quality of life. It is important to differentiate between severe therapy resistant asthma and difficult-to-treat asthma due to comorbidities. The most common problems that need to be excluded before a diagnosis of severe asthma can be made are poor medication adherence, poor medication technique or incorrect diagnosis of asthma. Difficult to treat asthma is a much more common reason for persistent symptoms and exacerbations and can be managed if comorbidities are clearly addressed. Children with persistent symptoms and exacerbations despite correct inhaler technique and good medical adherence to standard Step 4 asthma therapies according to the guidelines^1,2, should be referred to an asthma specialist with expertise in severe asthma.

Predictors of Hospital Reuse Among Publicly Insured Children Hospitalized for Status Asthmaticus

BACKGROUND

Asthma is a common cause of pediatric hospitalization. Nonadherence to asthma medications is associated with worse outcomes; however, there is a paucity of data regarding posthospitalization prescription filling and hospital reuse. Our objective was to identify patients at risk for hospital reuse after being hospitalized for asthma.

METHODS

This is a retrospective study of patients with asthma who were discharged from a children's hospital in which we use Medicaid claims data to evaluate prescription fills within 30 days and 12 months. Chart reviews were used for demographics, chronic asthma severity, admission severity, and hospital reuse. t and χ² tests were performed for continuous and categorical variables. A generalized linear mixed model was fitted to predict the odds of hospital reuse, which was defined as requiring an emergency department visit or rehospitalization. Survival analysis using log-rank testing was used for modeling the time to hospital reuse.

RESULTS

Fifty-four percent of patients discharged with asthma had hospital reuse within 1 year of discharge. There was no association between hospital reuse and prescription filling for systemic steroids (odds ratio [OR] 1.30; confidence interval [CI]: 0.85-2.00; P = .21) or controller medications (OR 1.5; CI: 0.92-2.52; P = .10). There was a higher number of controller and systemic steroid prescription fills over 12 months for patients with hospital reuse. The factors associated with greater odds of hospital reuse were severity of chronic asthma diagnosis (P = .03) as well as African American race (OR 1.92; CI: 1.17-3.13; P = .01).

CONCLUSIONS

For Medicaid-insured patients discharged with asthma, worse chronic asthma severity and African American race were associated with greater odds of hospital reuse. Decreased prescription filling was not associated with greater odds of hospital reuse.

High prevalence of house dust mite sensitization in children with severe asthma living at high altitude in a tropical country

BACKGROUND

Some studies, mainly in Europe, have shown a low level of sensitization to house dust mite (HDM) allergens at high altitude (HA). Differently, some others in tropical countries have shown a higher level. The aim of this study was to evaluate allergens sensitization, including HDM, in children with severe asthma (SA), residents at HA in a tropical middle-income developing country.

METHODS

Observational, analytical, cross-sectional study in children aged 6-15 years old with SA at HA (2640 m). Skin prick tests (SPT), serum IgE, exhaled fraction of nitric oxide (FE_NO ), spirometry, and asthma questionnaire (ACT) were performed. Associations were explored by Pearson or Spearman coefficients.

RESULTS

We included 61 children. Most patients were male (61.3%), median age: 10 years (Interquartile range [IQR]: 8-12), median BMI: 17 kg/m² (IQR: 16-20); Median of positive SPT: 2 (IQR: 2-3). At least one SPT was positive in 88.7% of patients and 87.9% were positive for at least one HDM. Serum IgE: 348 UI/mL (IQR: 154-760) and FE_NO : 22 ppb (IQR: 9-41). Prebronchodilator values were (% predicted): FVC: 109.7% (±15.5%), FEV₁ : 98.4% (±16.3); FEV₁ /FVC: 82% (±8%). SPT were inversely correlated with the FEV₁ /FVC (Rho: -0.34; 95% CI: -0.55 a -0.09; P = 0.008).

CONCLUSIONS

These children with SA living at HA in a tropical middle-income developing country have a high prevalence of HDM sensitization. One explanation for this might be that tropical conditions, such as temperature and humidity, could modify the effect of the altitude on asthma.

Severe Asthma: Challenges and Pitfalls in Management

A small but significant subset of asthmatic children show a lack of response to standard management, resulting in further intensification of therapy to optimise symptom control and may remain symptomatic despite maximal therapy. Severe asthma results in increased risk of adverse outcomes whilst contributing significantly to the economic burden on the nation's health resources. The ERS / ATS guidelines were published in 2014 and form the basis of identifying, evaluating and managing severe asthmatic children. However, much of this evidence is extrapolated from adult studies and may be inappropriate in children as unlike adults, children have a more atopic phenotype. Severe asthma is an umbrella term and may represent several overlapping heterogeneous wheezing entities. This chapter aims at discussing the strategies employed in managing severe asthmatic children with particular focus on diagnostic challenges and management pitfalls. Particular emphasis is put into the logical and systematic approach to a child with severe asthma and describes the multidisciplinary approach to manage these children. Finally, this chapter describes the novel therapies available in children and in adults in managing this challenging condition.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

National estimates of 30-day readmissions among children hospitalized for asthma in the United States

OBJECTIVE

Previous single-center studies have reported that up to 40% of children hospitalized for asthma will be readmitted. The study objectives are to investigate the prevalence and timing of 30-day readmissions in children hospitalized with asthma, and to identify factors associated with 30-day readmissions.

METHODS

Data (n = 12,842) for children aged 6-18 years hospitalized for asthma were obtained from the 2013 Nationwide Readmission Database (NRD). The primary study outcome was time to readmission within 30 days after discharge attributable to any cause. Several predictors associated with the risk of admission were included: patient (age, sex, median household income, insurance type, county location, and pediatric chronic complex condition), admission (type, day, emergency services utilization, length of stay (LOS), and discharge disposition), and hospital (ownership, bed size, and teaching status). Cox's proportional hazards model was used to identify predictors.

RESULTS

Of 12,842 asthma-related index hospitalizations, 2.5% were readmitted within 30-days post-discharge. Time to event models identified significantly higher risk of readmission among asthmatic children aged 12-18 years, those who resided in micropolitan counties, those with >4-days LOS during index hospitalization, those who were hospitalized in an urban hospital, who had unfavorable discharge (hazard ratio 2.53, 95% confidence interval 1.33-4.79), and those who were diagnosed with a pediatric complex chronic condition, respectively, than children in respective referent categories.

CONCLUSION

A multi-dimensional approach including effective asthma discharge action plans and follow-up processes, home-based asthma education, and neighborhood/community-level efforts to address disparities should be integrated into the routine clinical care of asthma children.

Rationale and design of the multiethnic Pharmacogenomics in Childhood Asthma consortium

AIM

International collaboration is needed to enable large-scale pharmacogenomics studies in childhood asthma. Here, we describe the design of the Pharmacogenomics in Childhood Asthma (PiCA) consortium.

MATERIALS & METHODS

Investigators of each study participating in PiCA provided data on the study characteristics by answering an online questionnaire.

RESULTS

A total of 21 studies, including 14,227 children/young persons (58% male), from 12 different countries are currently enrolled in the PiCA consortium. Fifty six percent of the patients are Caucasians. In total, 7619 were inhaled corticosteroid users. Among patients from 13 studies with available data on asthma exacerbations, a third reported exacerbations despite inhaled corticosteroid use. In the future pharmacogenomics studies within the consortium, the pharmacogenomics analyses will be performed separately in each center and the results will be meta-analyzed.

CONCLUSION

PiCA is a valuable platform to perform pharmacogenetics studies within a multiethnic pediatric asthma population.

What do adolescents with asthma really think about adherence to inhalers? Insights from a qualitative analysis of a UK online forum

OBJECTIVE

To explore the barriers and facilitators to inhaled asthma treatment in adolescents with asthma.

DESIGN

Qualitative analysis of posts about inhaler treatment in adolescents from an online forum for people with asthma. Analysis informed by the Perceptions and Practicalities Approach.

PARTICIPANTS

Fifty-four forum participants (39 adolescents ≥16 years, 5 parents of adolescents, 10 adults with asthma) identified using search terms 'teenager inhaler' and 'adolescent inhaler'.

SETTING

Posts from adolescents, parents and adults with asthma taking part in the Asthma UK online forum between 2006 and 2016, UK.

RESULTS

Practical barriers reducing the ability to adhere included forgetfulness and poor routines, inadequate inhaler technique, organisational difficulties (such as repeat prescriptions), and families not understanding or accepting their child had asthma. Prompting and monitoring inhaler treatment by parents were described as helpful, with adolescents benefiting from self-monitoring, for example, by using charts logging adherence. Perceptions reducing the motivation to adhere included asthma representation as episodic rather than chronic condition with intermittent need of inhaler treatment. Adolescents and adults with asthma (but not parents) described concerns related to attributed side effects (eg, weight gain) and social stigma, resulting in 'embarrassment of taking inhalers'. Facilitators to adherence included actively seeking general practitioners'/consultants' adjustments if problems arose and learning to deal with the side effects and stigma. Parents were instrumental in creating a sense of responsibility for adherence.

CONCLUSIONS

This online forum reveals a rich and novel insight into adherence to asthma inhalers by adolescents. Interventions that prompt and monitor preventer inhaler use would be welcomed and hold potential. In clinical consultations, exploring parents' beliefs about asthma diagnosis and their role in dealing with barriers to treatment might be beneficial. The social stigma of asthma and its role in adherence were prominent and continue to be underestimated, warranting further research and action to improve public awareness of asthma.

Barriers and facilitators to asthma self-management in adolescents: A systematic review of qualitative and quantitative studies

BACKGROUND

Many adolescents have poor asthma control and impaired quality of life despite the availability of modern pharmacotherapy. Research suggests that poor adherence to treatment and limited engagement in self-management could be contributing factors.

OBJECTIVE

To conduct a systematic review of the barriers and facilitators to self-management of asthma reported by adolescents using a narrative synthesis approach to integrate the findings.

DESIGN

MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for all types of study design. Full papers were retrieved for study abstracts that included data from participants aged 12-18 years referring to barriers or facilitators of asthma self-management behaviors.

RESULTS

Sixteen studies (5 quantitative and 11 qualitative) underwent data extraction, quality appraisal, and thematic analysis. Six key themes were generated that encompassed barriers and/or facilitators to self-management of asthma in adolescents: Knowledge, Lifestyle, Beliefs and Attitudes, Relationships, Intrapersonal Characteristics, and Communication.

CONCLUSIONS

There is a pressing need to prepare adolescents for self-management, using age-appropriate strategies that draw on the evidence we have synthesized. Current clinical practice should focus on ensuring adolescents have the correct knowledge, beliefs, and positive attitude to self-manage their illness. This needs to be delivered in a supportive environment that facilitates two-way communication, fosters adolescents' self-efficacy to manage their disease, and considers the wider social influences that impinge on self-management. Pediatr Pulmonol. 2017;52:430-442. © 2016 Wiley Periodicals, Inc.

Combining an epithelial repair factor and anti-fibrotic with a corticosteroid offers optimal treatment for allergic airways disease

BACKGROUND AND PURPOSE

We evaluated the extent to which individual versus combination treatments that specifically target airway epithelial damage [trefoil factor-2 (TFF2)], airway fibrosis [serelaxin (RLX)] or airway inflammation [dexamethasone (DEX)] reversed the pathogenesis of chronic allergic airways disease (AAD).

EXPERIMENTAL APPROACH

Following induction of ovalbumin (OVA)-induced chronic AAD in 6–8 week female Balb/c mice, animals were i.p. administered naphthalene (NA) on day 64 to induce epithelial damage, then received daily intranasal administration of RLX (0.8 mg·mL(−1)), TFF2 (0.5 mg·mL(−1)), DEX (0.5 mg·mL(−1)), RLX + TFF2 or RLX + TFF2 + DEX from days 67–74. On day 75, lung function was assessed by invasive plethysmography, before lung tissue was isolated for analyses of various measures. The control group was treated with saline + corn oil (vehicle for NA).

KEY RESULTS

OVA + NA-injured mice demonstrated significantly increased airway inflammation, airway remodelling (AWR) (epithelial damage/thickness; subepithelial myofibroblast differentiation, extracellular matrix accumulation and fibronectin deposition; total lung collagen concentration), and significantly reduced airway dynamic compliance (cDyn). RLX + TFF2 markedly reversed several measures of OVA + NA-induced AWR and normalized the reduction in cDyn. The combined effects of RLX + TFF2 + DEX significantly reversed peribronchial inflammation score, airway epithelial damage, subepithelial extracellular matrix accumulation/fibronectin deposition and total lung collagen concentration (by 50–90%) and also normalized the reduction of cDyn.

CONCLUSIONS AND IMPLICATIONS

Combining an epithelial repair factor and anti-fibrotic provides an effective means of treating the AWR and dysfunction associated with AAD/asthma and may act as an effective adjunct therapy to anti-inflammatory corticosteroids

Transcriptome analysis of controlled and therapy-resistant childhood asthma reveals distinct gene expression profiles

BACKGROUND

Children with problematic severe asthma have poor disease control despite high doses of inhaled corticosteroids and additional therapy, leading to personal suffering, early deterioration of lung function, and significant consumption of health care resources. If no exacerbating factors, such as smoking or allergies, are found after extensive investigation, these children are given a diagnosis of therapy-resistant (or therapy-refractory) asthma (SA).

OBJECTIVE

We sought to deepen our understanding of childhood SA by analyzing gene expression and modeling the underlying regulatory transcription factor networks in peripheral blood leukocytes.

METHODS

Gene expression was analyzed by using Cap Analysis of Gene Expression in children with SA (n = 13), children with controlled persistent asthma (n = 15), and age-matched healthy control subjects (n = 9). Cap Analysis of Gene Expression sequencing detects the transcription start sites of known and novel mRNAs and noncoding RNAs.

RESULTS

Sample groups could be separated by hierarchical clustering on 1305 differentially expressed transcription start sites, including 816 known genes and several novel transcripts. Ten of 13 tested novel transcripts were validated by means of RT-PCR and Sanger sequencing. Expression of RAR-related orphan receptor A (RORA), which has been linked to asthma in genome-wide association studies, was significantly upregulated in patients with SA. Gene network modeling revealed decreased glucocorticoid receptor signaling and increased activity of the mitogen-activated protein kinase and Jun kinase cascades in patients with SA.

CONCLUSION

Circulating leukocytes from children with controlled asthma and those with SA have distinct gene expression profiles, demonstrating the possible development of specific molecular biomarkers and supporting the need for novel therapeutic approaches.

Risk factors associated with hospital readmission in pediatric asthma

Asthma is a leading cause of hospitalization among children, and about 15-50% of pediatric patients are readmitted after an index admission. The purpose of this integrative review is to explore contemporary scientific findings on the association between pediatric asthma readmission and various demographic, environmental, psychosocial and clinical risk factors. An electronic database search resulted in a sample of 29 studies. African American, public or no insurers, previous admission and complex chronic comorbidity were identified as risk factors associated with pediatric asthma readmission. However, more interdisciplinary and well-designed investigations are warranted to further explicate the spectrum of environmental and psychosocial correlates.

Parental socioeconomic status, childhood asthma and medication use--a population-based study

Background

Little is known about how parental socioeconomic status affects offspring asthma risk in the general population, or its relation to healthcare and medication use among diagnosed children.

Methods

This register-based cohort study included 211,520 children born between April 2006 and December 2008 followed until December 2010. Asthma diagnoses were retrieved from the National Patient Register, and dispensed asthma medications from the Prescribed Drug Register. Parental socioeconomic status (income and education) were retrieved from Statistics Sweden. The associations between parental socioeconomic status and outcomes were estimated by Cox proportional hazard regression.

Results

Compared to the highest parental income level, children exposed to all other levels had increased risk of asthma during their first year of life (e.g. hazard ratio, HR 1.19, 95% confidence interval, CI 1.09–1.31 for diagnosis and HR 1.17, 95% CI 1.08–1.26 for medications for the lowest quintile) and the risk was decreased after the first year, especially among children from the lowest parental income quintile (HR 0.84, 95% CI 0.77–0.92 for diagnosis, and HR 0.80, 95% CI 0.74–0.86 for medications). Further, compared to children with college-educated parents, those whose parents had lower education had increased risk of childhood asthma regardless of age. Children with the lowest parental education had increased risk of an inpatient (HR 2.07, 95% CI 1.61–2.65) and outpatient (HR 1.32, 95% CI 1.18–1.47) asthma diagnosis. Among diagnosed children, those from families with lower education used fewer controller medications than those whose parents were college graduates.

Conclusions

Our findings indicate an age-varying association between parental income and childhood asthma and consistent inverse association regardless of age between parental education and asthma incidence, dispensed controller medications and inpatient care which should be further investigated and remedied.

Readmissions among children previously hospitalized with pneumonia

BACKGROUND AND OBJECTIVES

Pneumonia is a leading cause of hospitalization and readmission in children. Understanding the patient characteristics associated with pneumonia readmissions is necessary to inform interventions to reduce avoidable hospitalizations and related costs. The objective of this study was to characterize readmission rates, and identify factors and costs associated with readmission among children previously hospitalized with pneumonia.

METHODS

Retrospective cohort study of children hospitalized with pneumonia at the 43 hospitals included in the Pediatric Health Information System between January 1, 2008, and December 31, 2011. The primary outcome was all-cause readmission within 30 days after hospital discharge, and the secondary outcome was pneumonia-specific readmission. We used multivariable regression models to identify patient and hospital characteristics and costs associated with readmission.

RESULTS

A total of 82 566 children were hospitalized with pneumonia (median age, 3 years; interquartile range 1-7). Thirty-day all-cause and pneumonia-specific readmission rates were 7.7% and 3.1%, respectively. Readmission rates were higher among children <1 year of age, as well as in patients with previous hospitalizations, longer index hospitalizations, and complicated pneumonia. Children with chronic medical conditions were more likely to experience all-cause (odds ratio 3.0; 95% confidence interval 2.8-3.2) and pneumonia-specific readmission (odds ratio 1.8; 95% confidence interval 1.7-2.0) compared with children without chronic medical conditions. The median cost of a readmission ($11 344) was higher than that of an index admission ($4495; P = .01). Readmissions occurred in 8% of pneumonia hospitalizations but accounted for 16.3% of total costs for all pneumonia hospitalizations.

CONCLUSIONS

Readmissions are common after hospitalization for pneumonia, especially among young children and those with chronic medical conditions, and are associated with substantial costs.

Examining household asthma management behavior through a microeconomic framework

National guidelines on the effective management of pediatric asthma have been promoted for over 20 years, yet asthma-related morbidity among low-income children remains disproportionately high. To date, household and clinical interventions designed to remediate these differences have been informed largely by a health behavior framework. However, these programs have not resulted in consistent sustained improvements in targeted populations. The continued funding and implementation of programs based on the health behavior framework leads us to question if traditional behavioral models are sufficient to understand and promote adaptation of positive health management behaviors. We introduce the application of the microeconomic framework to investigate potential mechanisms that can lead to positive management behaviors to improve asthma-related morbidity. We provide examples from the literature on health production, preferences, trade-offs and time horizons to illustrate how economic constructs can potentially add to understanding of disease management. The economic framework, which can be empirically observed, tested, and quantified, can explicate the engagement in household-level activities that would affect health and well-being. The inclusion of a microeconomic perspective in intervention research may lead to identification of mechanisms that lead to household decisions with regard to asthma management strategies and behavior. The inclusion of the microeconomic framework to understand the production of health may provide a novel theoretical framework to investigate the underlying causal behavioral mechanisms related to asthma management and control. Adaptation of an economic perspective may provide new insight into the design and implementation of interventions to improve asthma-related morbidity in susceptible populations.

Rehospitalization for childhood asthma: timing, variation, and opportunities for intervention

OBJECTIVE

To assess the timing of pediatric asthma rehospitalization, variation in rate of rehospitalization across hospitals, and factors associated with rehospitalization at different intervals.

STUDY DESIGN

Retrospective cohort analysis of 44,204 hospitalizations for children with asthma within 42 children's hospitals between July 2008 and June 2011. The main outcome measures were rehospitalization for asthma within 7, 15, 30, 60, 180, and 365 days of an index asthma admission.

RESULTS

The rate of asthma rehospitalization ranged from 0.5% (n = 208) at 7 days to 17.2% (n = 7603) at 365 days. Black patients and patients with public insurance had higher odds of rehospitalization at 60 days and beyond (P ≤ .01 for both). Adolescents (12- to 18-year-old), patients with a diagnosis of a complex chronic condition, and patients with a prior year asthma admission had higher odds of rehospitalization at every time interval (P ≤ .001 for all). Significant hospital variation in case-mix adjusted rates of rehospitalization existed at each time interval (P ≤ .01 for all). Rates at 365 days were ≤ 10.9% for the top 10% of hospitals; if all hospitals achieved this rate, 36.6% of rehospitalizations might have been avoided.

CONCLUSIONS

Significant variation in asthma rehospitalization rates exists across children's hospitals from 7 to 365 days after an index admission. Racial/ethnic and economic disparities emerge at 60 days. By 1 year, rehospitalizations account for 1 in 6 hospitalizations. Assessing asthma rehospitalizations at longer intervals may augment our current understanding of and approach to post-hospitalization care improvement.

Inflammatory phenotypes underlying uncontrolled childhood asthma despite inhaled corticosteroid treatment: rationale and design of the PACMAN2 study

BACKGROUND

The diagnosis of childhood asthma covers a broad spectrum of pathological mechanisms that can lead to similarly presenting clinical symptoms, but may nonetheless require different treatment approaches. Distinct underlying inflammatory patterns are thought to influence responsiveness to standard asthma medication.

METHODS/DESIGN

The purpose of the PACMAN2 study is to identify inflammatory phenotypes that can discriminate uncontrolled childhood asthma from controlled childhood asthma by measures in peripheral blood and exhaled air. PACMAN2 is a nested, case-control follow-up study to the ongoing pharmacy-based "Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects" (PACMAN) study. The original PACMAN cohort consists of children aged 4-12 years with reported use of asthma medication. The PACMAN2 study will be conducted within the larger PACMAN cohort, and will focus on detailed phenotyping of a subset of the PACMAN children. The selected participants will be invited to a follow-up visit in a clinical setting at least six months after their baseline visit based on their adherence to usage of inhaled corticosteroids, their asthma symptoms in the past year, and their age (≥ 8 years). During the follow-up visit, current and long-term asthma symptoms, medication use, environmental factors, medication adherence and levels of exhaled nitric oxide will be reassessed. The following measures will also be examined: pulmonary function, exhaled volatile organic compounds, as well as inflammatory markers in peripheral blood and blood plasma. Comparative analysis and cluster-analyses will be used to identify markers that differentiate children with uncontrolled asthma despite their use of inhaled corticosteroids (ICS) (cases) from children whose asthma is controlled by the use of ICS (controls).

DISCUSSION

Asthmatic children with distinct inflammatory phenotypes may respond differently to anti-inflammatory therapy. Therefore, by identifying inflammatory phenotypes in children with the PACMAN2 study, we may greatly impact future personalised treatment strategies, uncover new leads for therapeutic targets and improve the design of future clinical studies in the assessment of the efficacy of novel therapeutics.

Childhood asthma: diagnosis and treatment

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

The oral corticosteroid-sparing effect of omalizumab in children with severe asthma

OBJECTIVE

To report the oral corticosteroid-sparing effect of omalizumab in children with severe asthma.

DESIGN

16-week therapeutic trial.

SETTING

Tertiary paediatric asthma clinic.

PATIENTS

34 children with severe asthma maintained on oral prednisolone (median age 12 years; 15 children <12 years and 19 children ≥12 years).

INTERVENTIONS

Fortnightly or monthly subcutaneous injections of omalizumab; the dose was calculated as per manufacturer's instructions based on body weight and serum immunoglobulin E concentration.

MAIN OUTCOME MEASURES

Reduction in prednisolone dose; mini-Asthma Quality of Life Questionnaire (AQLQ); Childhood Asthma Control Test (ACT); forced expiratory volume in 1 s (FEV(1)).

RESULTS

Median daily prednisolone dose reduced from 20 mg to 5 mg (n=34, p<0.0001), including seven children who stopped prednisolone completely. Mini-AQLQ score increased from 3.5 to 5.9 (n=24, p<0.0001). Childhood ACT score increased from 12 to 20 (n=23, p=0.0001). FEV(1) increased from 2.10 to 2.25 litres (n=31, non-significant). The reduction in prednisolone dose and improvements in mini-AQLQ and childhood ACT were significant in children both under and over 12 years of age, with no differences in outcome detected between these two groups.

CONCLUSIONS

A 16-week therapeutic trial of omalizumab allowed a significant reduction in daily prednisolone dose and was associated with improvements in asthma control and quality of life in 34 children with severe asthma. Similar benefits were seen in children both above and below 12 years of age. These uncontrolled data are very encouraging. There is an urgent requirement for a multicentre randomised placebo-controlled trial of omalizumab in children with severe asthma, with reduction in oral corticosteroid dose as the primary outcome measure.

Biomarkers of therapy responsiveness in asthma: pitfalls and promises

Asthma is one of the most common chronic diseases worldwide. There is a large inter-individual variability in response to asthma treatment. Most patients respond well to standard therapy; however, a small proportion of the patients remain symptomatic despite treatment with high dosages of corticosteroids. Uncontrolled asthma leads to a decreased quality of life. Therefore, it is important to identify individuals who will respond poorly to standard asthma medication, especially to standard maintenance therapy with inhaled corticosteroids, at an early stage. Response to anti-inflammatory therapy is generally monitored by the assessment of clinical symptoms, which only partially correlates with underlying airway inflammation. The identification of specific inflammatory biomarkers might help to guide treatment or predict a corticosteroid response more accurately. Some inflammatory biomarkers are already finding their way into clinical practice (e.g. fraction of nitric oxide in exhaled breath), whereas others are predominantly used as a research tool (e.g. profiles of volatile organic compounds). Currently, there is no inflammatory biomarker used in routine clinical practice to predict a corticosteroid response. More knowledge on the underlying biological mechanism(s) of heterogeneous therapeutic responses could help to identify novel biomarkers. This review will focus on inflammatory patterns and genetic variations that may underlie differences in treatment response in patients with asthma, and will provide an overview of inflammatory biomarkers that could potentially serve as response predictors.

Treatment of psychological factors in a child with difficult asthma: a case report

Difficult asthma is defined as the persistence of asthma symptoms, abnormal pulmonary function showing airway obstruction, and continued requirement for short-acting bronchodilator therapy, despite adequate treatment with inhaled corticosteroids. It calls for a thorough evaluation of the patient to look into alternate and complicating diagnoses. The authors report a case of a 9-year-old patient with difficult asthma who failed to respond to conventional therapy. Although it was recognized that he had a number of potential medical complicating factors including allergies, chronic sinusitis, and gastroesophageal reflux, a psychological intervention using hypnosis ultimately appeared to help alleviate his symptoms completely. Thus, psychological evaluation and intervention should be considered early in the course of management of a patient with difficult asthma, because it may help avoid time-consuming and expensive investigations of potential complicating factors, and it may yield rapid improvement in the patient's clinical condition.

Clinical, radiological, and physiological differences between obliterative bronchiolitis and problematic severe asthma in adolescents and young adults: the early origins of the overlap syndrome?

PURPOSE

Few reports have compared chronic obstructive lung diseases (OLDs) starting in childhood.

AIMS

To describe functional, radiological, and biological features of obliterative bronchiolitis (OB) and further discriminate to problematic severe asthma (PSA) or to diagnose a group with overlapping features.

RESULTS

Patients with OB showed a greater degree of obstructive lung defect and higher hyperinflation (P < 0.001). The most frequent high-resolution computed tomography (HRCT) features (increased lung volume, inspiratory decreased attenuation, mosaic pattern, and expiratory air trapping) showed significantly greater scores in OB patients. Patients with PSA have shown a higher frequency of atopy (P < 0.05). ROC curve analysis demonstrated discriminative power for the LF variables, HRCT findings and for atopy between diagnoses. Further analysis released five final variables more accurate for the identification of a third diagnostic group (FVC%t, post-bronchodilator ΔFEV(1) in ml, HRCT mosaic pattern, SPT, and D. pteronyssinus-specific IgE).

CONCLUSIONS

We found that OB and PSA possess identifiable characteristic features but overlapping values may turn them undistinguishable.

Refractory asthma coexisting with a double aortic arch: a case report and literature review

Asthma that is poorly controlled despite adequate treatment should be investigated for medication compliance, treatment adherence, environmental control, asthma mimics, and comorbidities especially in infants and young children. Here, the case of a 2-year-old child with refractory asthma coexisting with a double aortic arch is reported.

Wheeze in children: the impact of parental education on atopic and non-atopic symptoms

There is conflicting evidence for the relationship between parental socioeconomic position and their children's asthma. The aim of this study was to investigate relationships between parental education and respiratory symptoms in their children, distinguishing atopic and non-atopic symptoms. A cross-sectional survey among 3262 elementary school children (age 8-13) was performed; data on parental education were obtained for 3213 children. Parents completed a questionnaire on their child's allergic and respiratory symptoms, and potential explanatory variables including family history, indoor environment, and the child's medical history. Subsets of children were tested for atopy (n = 1983), lung function (n = 2325), and airway hyperresponsiveness (AHR) (n = 880). Logistic regression was used to assess relationships of health outcomes with parental education. A high parental education was associated with an increased risk of atopic sensitization to indoor allergens (OR 1.31, 95% CI 1.02; 1.69). Studied explanatory variables did not influence the relationship. In contrast, a high parental education protected children from wheeze (OR 0.77, 95% CI 0.61; 0.97). This only applied to non-atopic wheeze (OR 0.65, 95% CI 0.43; 0.99) and not to atopic wheeze (OR 0.89, 95% CI 0.60; 1.31). The protection from non-atopic wheeze in children of highly educated parents declined after adjustment for household smoking and breastfeeding (OR 0.96, 95% CI 0.58; 1.57). Similar results were observed for non-atopic and atopic rhinitis. We conclude that children from highly educated parents are protected from non-atopic respiratory symptoms, which is largely explained by a lower rate of household smoking and a higher rate of breastfeeding.

Asthma and obesity in childhood: on the road ahead

Epidemiological data show a link between asthma and obesity, suggesting many different mechanisms that may underlie the association. However, diagnosis of asthma is often self-reported by patients or caregivers. Definition of asthma is crucial, particularly in childhood. Obesity can be associated with symptoms commonly attributed to asthma, such as wheezing, dyspnoea and sleep apnoea. Obese subjects are less fit and may have more frequent bouts of breathlessness on exertion accompanied by an exaggerated symptom perception. Therefore, the link between the two diseases should be analysed by focusing not only on reported diagnosis of asthma but also on objective markers that can better characterize the asthma phenotype. These markers should include lung function parameters, bronchial hyper-reactivity, atopic sensitization and indices of lung inflammation. As we look back and move forward, a multidisciplinary approach is increasingly necessary to understand the complexity of obesity and asthma, keeping in mind that diet and exercise could influence both diagnosis and treatment. In the meantime, in clinical settings, physicians should be cautious about diagnosing asthma in obese children on the basis of self-reported symptoms alone and should confirm the diagnosis by using objective measurements and marker evaluations that can better identify asthma phenotype and exclude overdiagnosis.

[Diagnosis and treatment guidelines for difficult-to-control asthma in children]

Children suffering from difficult-to-control asthma (DCA) require frequent appointments with their physician, complex treatment regimes and often admissions to hospital. Less than 5% of the asthmatic population suffer this condition. DCA must be correctly characterised to rule out false causes of DCA and requires making a differential diagnosis from pathologies that mimic asthma, comorbidity, environmental and psychological factors, and analysing the factors to determine poor treatment compliance. In true DCA cases, inflammation studies (exhaled nitric oxide, induced sputum, broncho-alveolar lavage and bronchial biopsy), pulmonary function and other clinical aspects can classify DCA into different phenotypes which could make therapeutic decision-making easier.

'Difficult asthma': can symptoms be controlled in a structured environment?

OBJECTIVE

Difficult asthma implies persistent asthma symptoms despite therapy with high doses of inhaled corticosteroids. The objective was to evaluate children with difficult asthma in a setting that excludes aggravating factors such as poor treatment adherence and adverse environmental influences.

PATIENTS AND METHODS

Sixty children (> or =6 years) had been referred because of difficult asthma to the rehabilitation centre over a period of 10 years. The diagnosis of poor asthma symptom control was confirmed if exacerbations continued during stay in the centre or if symptoms interfered with daily activities at least 3 times a week.

RESULTS

The median stay at the centre was 5 months. In four patients a diagnosis other than asthma was made. In five patients symptom control remained difficult. In the remaining 51 children, asthma symptoms became well controlled. Many factors contributed to poor asthma control in the home setting: poor treatment adherence (n = 32), parental smoking (n = 22), allergen exposure (n = 10). Psychosocial problems occurred in 36 children. Contributing factors often co-existed. During stay at the centre, lung function improved in the group with well controlled asthma symptoms (P < 0.001) but not in the group with continued poor symptom control. In the majority of children who obtained good symptom control, this persisted in the years following discharge.

CONCLUSION

Of 60 children referred with a diagnosis of difficult asthma, optimal medical management in a structured environment resulted in good symptom control in 51 patients; symptom control remained poor in 5 patients, a diagnosis other than asthma was made in 4 patients.

Complexity of chronic asthma and chronic obstructive pulmonary disease: implications for risk assessment, and disease progression and control

Although assessment of asthma control is important to guide treatment, it is difficult since the temporal pattern and risk of exacerbations are often unpredictable. In this Review, we summarise the classic methods to assess control with unidimensional and multidimensional approaches. Next, we show how ideas from the science of complexity can explain the seemingly unpredictable nature of bronchial asthma and emphysema, with implications for chronic obstructive pulmonary disease. We show that fluctuation analysis, a method used in statistical physics, can be used to gain insight into asthma as a dynamic disease of the respiratory system, viewed as a set of interacting subsystems (eg, inflammatory, immunological, and mechanical). The basis of the fluctuation analysis methods is the quantification of the long-term temporal history of lung function parameters. We summarise how this analysis can be used to assess the risk of future asthma episodes, with implications for asthma severity and control both in children and adults.