Diagnosis of concomitant inducible laryngeal obstruction and asthma

Clinical Characteristics and Impact of Inducible Laryngeal Obstruction in the UK National Registry

BACKGROUND

Inducible laryngeal obstruction (ILO) describes inappropriate laryngeal closure during respiration, with airflow obstruction occurring at the glottic and/or supraglottic level, leading to breathlessness.

OBJECTIVE

There is a paucity of data describing the demographics and impact of ILO. We aimed to report the clinical and demographic features of ILO in individuals entered prospectively in the UK national ILO registry.

METHODS

Data were entered into a Web-based registry from participants with endoscopically confirmed ILO who were attending four established UK-wide specialist ILO centers between March 2017 and November 2019. All patients provided written informed consent.

RESULTS

Data from 137 individuals were included. Most (87%) had inspiratory ILO and required provocation during endoscopy to induce symptoms. There was a female predominance (80%), mean age 47 years (SD, 15 years). The most common comorbidities included asthma (68%) and reflux (57%). Health care use was high: 88% had attended emergency health care with symptoms at least once in the previous 12 months and nearly half had been admitted to the hospital. A fifth had required admission to critical care owing to ILO symptoms. Patient morbidity was substantial; 64% reported impaired functional capacity (≥3 on the Medical Research Council Dyspnoea Scale) and a third stated that symptoms affected working capability.

CONCLUSION

We describe the first multicenter prospective characterization of individuals with endoscopically diagnosed ILO. Analysis of our multicenter data set identified ILO as associated with a high burden of morbidity and health care use, comparable to severe asthma. These data will support the development of health care resources in the future and guide research priorities.

Exploring Factors Impacting Engagement in Speech Pathology Intervention for Inducible Laryngeal Obstruction

AIM

Speech pathology is the first-line treatment for inducible laryngeal obstruction (ILO) and involves behavioral techniques to address symptoms and modify maladaptive laryngeal postures. Benefit from speech pathology is reliant on patients engaging in treatment sessions, regular home practice, and generalizing techniques to everyday activities. There is limited research exploring engagement in speech pathology treatment for ILO, particularly from the patient perspective. This study aimed to explore the experiences of living with ILO and how this experience may impact the way patients engage in speech pathology treatment.

STUDY DESIGN

Qualitative study.

METHODS

Semistructured interviews were completed with seven participants exploring their experiences living with ILO, their diagnostic process and their experiences with speech pathology treatment. Data were analyzed using reflexive thematic analysis to determine shared meanings across participants and themes were developed.

FINDINGS

Three major themes were identified - Life with ILO, Challenges of Speech Pathology Treatment, and What Matters to Me. Patients' reports of living with ILO and interacting with speech pathology suggested that these experiences impacted their readiness to start treatment and persist through the challenges of the treatment. Engagement appeared to be positively associated with significant ILO symptom burden and life impact, confidence in the diagnostic process, recommendation for speech pathology treatment, a tailored intervention by a patient-perceived expert in the field and working in a partnership with the speech pathologist to develop a sense of agency. Patients indicated their engagement was negatively influenced by competing time demands, social embarrassment when using symptom relief techniques and laryngeal exercises, and a low ILO symptom burden and life impact.

CONCLUSION

The reasons behind engagement in speech pathology treatment for ILO appear to be a complex interaction between previous experiences of living with ILO including the diagnostic process and the experience of speech pathology treatment. A patient-centered approach to therapy may help to maximize engagement by exploring readiness and expectations for treatment. The greater understanding of the patient experience provided through this study may allow speech pathologists to devise meaningful ways to maximize engagement in treatment for people with ILO.

Vocal cord dysfunction/inducible laryngeal obstruction cannot be diagnosed from symptoms

Vocal cord dysfunction/inducible laryngeal obstruction is highly variable. Standard clinical symptoms and questionnaires cannot predict laryngoscopic diagnosis in a "lung disease" population. https://bit.ly/3QUtsbB.

Inducible Laryngeal Obstruction Differential Diagnosis in Adolescents and Adults: A Tutorial

Inducible laryngeal obstruction (ILO), formerly referred to as paradoxical vocal fold motion and vocal cord dysfunction, is a complex disorder of the upper airway that requires skillful differential diagnosis. There are several medical conditions that may mimic ILO (or which ILO may mimic) that should be considered in the differential diagnosis before evidence-supported behavioral intervention is initiated to mitigate or eliminate this upper airway condition. A key in treatment planning is determination of an isolated presentation of ILO or ILO concurrent with other conditions that affect the upper airway. Accurate, timely differential diagnosis in the clinical assessment of this condition mitigates delay of targeted symptom relief and/or insufficient intervention. Accurate assessment and nuanced clinical counseling are necessary to untangle concurrent, competing conditions in a single patient. This tutorial describes the common and rare mimics that may be encountered by medical professionals who evaluate and treat ILO, with particular attention to the role of the speech-language pathologist. Speech-language pathologists receive referrals for ILO from several different medical specialists (allergy, pulmonology, and sports medicine), sometimes without a comprehensive team assessment. It is paramount that speech-language pathologists who assess and treat this disorder have a solid understanding of the conditions that may mimic ILO. Summary tables that delineate differential diagnosis considerations for airway noise, origin of noise, symptoms, triggers, role of the speech-language pathologist, and β-agonist response are included for clinician reference. A clinical checklist is also provided to aid clinicians in the critical assessment process.

Diagnosis of vocal cord dysfunction / inducible laryngeal obstruction-A Delphi study protocol

INTRODUCTION

Currently there is no consistent and widely accepted approach to the diagnosis of vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO). Harmonised diagnostic methods are vital to enable optimal diagnosis, advance management and enable research. We aim to obtain consensus on how expert clinicians recognise and diagnose VCD/ILO.

METHODS AND ANALYSIS

Two-round modified Delphi, with workshop validation.

ETHICS AND DISSEMINATION

Institutional Board Review was obtained from the Monash Health Human Research Ethics Committee. The dissemination plan is for presentation and publication.

REGISTRATION DETAILS

Registered at Australia and New Zealand Clinical Trials Registry ACTRN12621001520820p.

Systematic review of the effectiveness of non-pharmacological interventions used to treat adults with inducible laryngeal obstruction

Introduction

Inducible laryngeal obstruction (ILO) describes transient laryngeal closure during respiration and can cause significant morbidity. Non-pharmacological behavioural therapy is the commonly cited treatment but efficacy is largely unknown.

Aim

To synthesise the current evidence base on the effectiveness of non-pharmacological interventions used to treat adults with ILO.

Methods

Electronic databases (Medline/Embase/CINAHL/PsycINFO/AMED/CENTRAL) were systematically searched, informed by a population, intervention, comparison, outcome framework. Two reviewers independently screened a representative sample, with lead-author completion due to excellent inter-rater reliability. Data was extracted using a predefined piloted form. Methodological quality was appraised (blindly by two reviewers) using the Joanna Briggs Institute Critical Appraisal Tools. A narrative synthesis was performed due to heterogeneity of studies (PROSPERO registration number: CRD42020213187).

Results

Initial searching identified 3359 records. Full-text screening occurred in 92 records and 14 studies, comprising 527 participants, were deemed eligible. All studies were low-level evidence (observational by design, with four case reports), with a high risk of bias; none contained control arms for comparison. Intervention description was inconsistently and poorly described but direction of effect was positive in 76% of outcomes measured. The majority of studies showed a reduction in symptom scores and improved direct laryngeal imaging post intervention; there was an overall reduction, 59.5%, in healthcare utilisation.

Discussion

The literature is in an embryonic state and lacks robust data to truly inform on the effectiveness of non-pharmacological interventions used to treat adults with ILO. However, positive signals in the synthesis performed support non-pharmacological treatment approaches and further development is warranted.

Paediatric asthma - all that wheezes is not necessarily asthma - current diagnostic and management strategies

PURPOSE OF REVIEW

Asthma is a frequently encountered chronic medical condition encountered in paediatrics, affecting 7% of children under the age of 18 in the United States. Although asthma is one of the more common conditions that is associated with wheezing, there is a broad differential diagnosis to consider. The purpose of this review is to describe other causes of wheezing outside of asthma in a paediatric population and discuss diagnostic and management strategies to consider when evaluating a child or adolescent with wheezing.

RECENT FINDINGS

The characteristics of the wheezing along with other associated signs and symptoms can be helpful in narrowing the differential diagnosis. The age and the past medical history of the patient are also important aspects to consider when determining next steps in the evaluation and management of paediatric wheezing. In addition to considering other causes of wheezing, it is often necessary to assess for the presence of underlying asthma, and recently updated asthma guidelines from the National Heart, Lung and Blood Institute provide a graded review of various recommendations for making the diagnosis and managing asthma in the clinical setting.

SUMMARY

It is important to maintain a broad differential diagnosis when evaluating a paediatric patient with wheezing.

The Role of Comorbidities in Difficult-to-Control Asthma in Adults and Children

Assessment of asthma comorbidities, conditions that adversely affect the pathobiology of asthma or impair its response to therapies, is a fundamental step in the evaluation and management of patients with difficult-to-treat asthma. Identifying and effectively treating asthma comorbidities, such as obesity, obstructive sleep apnea, and chronic sinusitis with nasal polyps, may improve asthma control and reduce exacerbations. In addition, identifying comorbid T2 inflammatory conditions may help guide optimal selection of biologic therapies. Here, we describe common comorbid conditions found in adult and pediatric difficult-to-control asthma, discuss evidence for the association with asthma morbidity and treatment benefit, and provide information on how and when to assess comorbidities.

Diagnostic and Therapeutic Outcomes Following Systematic Assessment of Patients with Concurrent Suspected Vocal Cord Dysfunction and Asthma

BACKGROUND

Vocal cord dysfunction (VCD) is present in 25% to 50% of patients with asthma. When both diagnoses are suspected, accurate diagnosis and targeted management represent a clinical challenge.

OBJECTIVE

To evaluate diagnostic and therapeutic outcomes following systematic assessment for patients with concurrent suspected VCD and asthma.

METHODS

Patients underwent systematic evaluation by clinical assessment and validated questionnaires, followed by multidisciplinary management. VCD was confirmed by visualization of paradoxical vocal fold motion at baseline or following provocation. Asthma was confirmed by demonstrating variable airflow obstruction. Asthma medications were deescalated in those with low clinical probability of asthma and no variable airflow obstruction. Response to 2 or more sessions of speech pathology was assessed by subjective report and standardized questionnaires.

RESULTS

Among 212 consecutive patients, 62 (29%) patients had both VCD and asthma, 54 (26%) had VCD alone, 51 (24%) had asthma alone, and 45 (21%) had neither. Clinician assessment and the Laryngeal Hypersensitivity Questionnaire both predicted laryngoscopy-confirmed VCD. Deescalation or discontinuation of asthma therapy was possible in 37 of 59 (63%) patients without variable airflow obstruction, and was most successful (odds ratio, 5.5) in the presence of laryngoscopy-confirmed VCD (25 of 31, or 81%) Patients with VCD responded subjectively to 2 or more sessions of speech pathology, but laryngeal questionnaire scores did not improve.

CONCLUSIONS

Expert clinician assessment and the Laryngeal Hypersensitivity Questionnaire predict the presence of laryngoscopy-confirmed VCD. Systematic assessment for both VCD and asthma facilitates deescalation or discontinuation of unnecessary asthma medications. Subjective symptom improvement following speech pathology was not paralleled by laryngeal questionnaire scores in this cohort.

Laryngeal hypersensitivity and abnormal cough response during mannitol bronchoprovocation challenge

BACKGROUND AND OBJECTIVE

Inhalational challenge with dry mannitol powder may potentially induce cough by two mechanisms: airway bronchoconstriction or laryngeal irritation. This prospective observational study investigated laryngeal and bronchial components of cough induced by mannitol challenge.

METHODS

We recruited consecutive patients referred for clinical mannitol challenge. The Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) was administered. Throughout testing, coughs were audio-recorded to derive a cough frequency index per time and dose of mannitol. Relationships between cough indices, laryngeal hypersensitivity and bronchial hyperresponsiveness (BHR) were examined. Participants were classified by cough characteristics with k-means cluster analysis.

RESULTS

Of 90 patients who underwent challenge, 83 completed both the questionnaire and challenge. Cough frequency was greater in patients with abnormal laryngeal hypersensitivity (p = 0.042), but not in those with BHR. There was a moderate negative correlation between coughs per minute and laryngeal hypersensitivity score (r = -0.315, p = 0.004), with lower LHQ scores being abnormal. Cluster analysis identified an older, female-predominant cluster with higher cough frequency and laryngeal hypersensitivity, and a younger, gender-balanced cluster with lower cough frequency and normal laryngeal sensitivity.

CONCLUSION

Cough frequency during mannitol challenge in our cohort reflected laryngeal hypersensitivity rather than BHR. Laryngeal hypersensitivity was more often present among older female patients. With the incorporation of cough indices, mannitol challenge may be useful to test for laryngeal hypersensitivity as well as BHR.

Asthma and Comorbid Conditions-Pulmonary Comorbidity

Pulmonary comorbidities can increase disease severity and health care costs associated with asthma management. Vocal cord dysfunction/inducible laryngeal obstruction is a common comorbidity that results from intermittent laryngeal obstruction. Patients describe distinct episodes of dyspnea that do not respond to bronchodilators. Inspiratory stridor is common. The gold standard diagnostic testing strategy is continuous laryngoscopy performed during exercise or irritant challenges. Dysfunctional breathing (DB) is an overarching term that describes conditions with a chronic change in the pattern of breathing that results in pulmonary and extrapulmonary symptoms. The prevalence of DB in asthma is up to 30%, and breathing retraining can improve symptoms and quality of life in people with DB and asthma. Asthma-chronic obstructive pulmonary disease overlap (ACO) refers to both asthmatics who develop fixed airflow obstruction after a history of exposure to smoke or biomass and patients with chronic obstructive pulmonary disease who have "asthmatic features" such as a large bronchodilator response, elevated levels of serum IgE, or peripheral eosinophil counts ≥300 per μL. Triple inhaler therapy with inhaled corticosteroid/long-acting beta-agonist/long-acting muscarinic should be considered in people with ACO and severe symptoms or frequent exacerbations. The clinical expression of bronchiectasis involves persistent mucus hypersecretion, recurrent exacerbations of infective bronchitis, incompletely reversible airflow obstruction, and lung fibrosis and can occur in up to 30% of adults with longstanding asthma. The treatable traits strategy is a useful model of care to manage the complexity and heterogeneity of asthma with pulmonary comorbidity.

Updated review of reported cases of reactive airways dysfunction syndrome

BACKGROUND

A previous systematic review of the diagnosis of reactive airways dysfunction syndrome (RADS), undertaken from 1985 to 2004, found a lack of standardization of case reporting, thus misattribution of symptoms can occur.

AIMS

We aimed to update the systematic review, update the list of reported causes and see whether a more structured approach to reporting has been adopted.

METHODS

We undertook a systematic literature review, using the databases EMBASE and Ovid MEDLINE, with search terms 'reactive airways dysfunction syndrome' or 'asthma AND acute irritant', and reported according to PRISMA guidelines. We included papers and abstracts published from January 2005 to September 2019, and articles were grouped by the presence or absence of diagnostic features: 'definite' RADS (met Brooks' criteria) or 'possible' RADS (Brooks' criteria not met or insufficient data). We collected demographic and diagnostic data for cases, where given.

RESULTS

Eleven papers and six conference abstracts met the inclusion criteria, 13 of which were case series or reports, and comprised 752 cases in total; seven articles met Brooks' criteria for RADS diagnosis. A variety of agents were implicated, with chlorine or chlorine-releasing molecules most frequently reported.

CONCLUSIONS

A lack of standardized reporting of RADS remains. The majority of published articles and conference abstracts either do not meet, or contain insufficient data to judge against, Brooks' criteria, particularly in relation to onset of symptoms and bronchial hyper-reactivity or variability of airflow obstruction. Some novel agents are described, in keeping with recognized structural taxonomies.

Work-Related Upper-Airway Disorders

Work-related rhinitis and laryngeal disorders are common and can significantly contribute to work absences and presenteeism. Each can cause respiratory symptoms that may be misdiagnosed as asthma symptoms, and each may occur as an isolated disorder or may also accompany asthma. Suspicion of these disorders and correct management require a careful medical and occupational history. Investigations for work-related rhinitis include examination of the nose, allergy skin tests, and in some cases, monitoring of peak inspiratory nasal flows at work and off work, or specific challenge tests. Work-related laryngeal disorders require assistance from an otolaryngologist and speech language pathologist.

Gastroesophageal reflux and asthma: when, how, and why

PURPOSE OF REVIEW

Gastro-esophageal reflux is a possible cause of uncontrolled symptoms of asthma and should be actively investigated and treated before severe asthma is diagnosed and biological therapy started.

RECENT FINDINGS

Recent investigations on esophageal function and tissue biomarkers in patients with asthma and associated GERD have established a relevant role for esophageal motility and neuronal sensory abnormalities in linking the two diseases. Characterization of the underpinning inflammatory substrate has showed mixed results as both neutrophilic and eosinophilic type 2 inflammatory changes have been described.

SUMMARY

New findings regarding inflammatory mechanisms in GERD-associated asthma as well as new diagnostic tools to investigate functional esophageal abnormalities and characterize asthma endotype have identified potential treatable traits that may improve the clinical management and outcome of asthmatic patients with GERD.

Asthma in Competitive Cross-Country Skiers: A Systematic Review and Meta-analysis

INTRODUCTION

In cross-country skiing, the repetitive ventilation of large amounts of cold and dry air strains the airways. The aim of this systematic review was to establish an overview of the current literature on asthma in cross-country skiers, biathletes and ski-orienteers.

METHODS

Six databases were searched on August 29, 2019. The search yielded 2161 articles. Thirty articles fulfilled the search criteria and were pooled together for a qualitative synthesis. Eight articles were included in the meta-analysis on the prevalence of asthma and the use of asthma medication.

RESULTS

According to the meta-analysis, the prevalence of self-reported physician-diagnosed asthma in skiers was 21% (95% CI 14-28%). The onset age of asthma was higher in skiers than in non-skiers with asthma. The prevalence of asthma medication use was on average 23% (CI 95% 19-26%). Several studies reported that asthma was underdiagnosed in skiers, as previously healthy skiers without a prior asthma diagnosis or medication use were frequently found to fulfill diagnostic criteria for asthma according to lung function tests. Studies using bronchial biopsy demonstrated that eosinophilic asthma is not detected in skiers with asthma as often as it is in non-skiers with asthma and that there are signs of airway inflammation even in non-asthmatic skiers.

CONCLUSION

Our findings suggest that the accuracy and coverage of diagnosing asthma in skiers has improved over the recent decades. However, the optimal treatment and natural course of asthma in this population remain unclear. Future research should investigate how the intensity of training, airway infections and their treatment affect the development of asthma among skiers.

PRD REGISTRATION NUMBER

CRD42017070940.

UK consensus statement on the diagnosis of inducible laryngeal obstruction in light of the COVID-19 pandemic

Prior to the COVID‐19 pandemic, laryngoscopy was the mandatory gold standard for the accurate assessment and diagnosis of inducible laryngeal obstruction. However, upper airway endoscopy is considered an aerosol‐generating procedure in professional guidelines, meaning routine procedures are highly challenging and the availability of laryngoscopy is reduced. In response, we have convened a multidisciplinary panel with broad experience in managing this disease and agreed a recommended strategy for presumptive diagnosis in patients who cannot have laryngoscopy performed due to pandemic restrictions. To maintain clinical standards whilst ensuring patient safety, we discuss the importance of triage, information gathering, symptom assessment and early review of response to treatment. The consensus recommendations will also be potentially relevant to other future situations where access to laryngoscopy is restricted, although we emphasize that this investigation remains the gold standard.

Laryngeal Dysfunction in Severe Asthma: A Cross-Sectional Observational Study

BACKGROUND

Laryngeal disorders can contribute to disease burden in severe asthma yet the nature of laryngeal disorders in severe asthma is poorly understood.

OBJECTIVE

The aim of this study was to examine laryngeal function in patients with severe asthma.

METHOD

A cross-sectional observational study involving 97 participants compared laryngeal function in patients with severe asthma (n = 53) with patients with laryngeal disorders of vocal cord dysfunction/inducible laryngeal obstruction (n = 16) and muscle tension dysphonia (n = 14), and with healthy controls (n = 13). A pre-post pilot study of speech pathology intervention for laryngeal symptoms was then provided to 11 participants with severe asthma and laryngeal dysfunction.

RESULTS

Laryngeal dysfunction was common in severe asthma. The majority of participants with severe asthma (87%) had laryngeal dysfunction, which affected respiration, phonation, or both. Three distinct patterns of laryngeal dysfunction in severe asthma were identified: (1) phonatory laryngeal dysfunction, (2) respiratory laryngeal dysfunction, and (3) combined laryngeal dysfunction. Laryngeal hypersensitivity and impaired voice measures were common in severe asthma. Patient-reported outcome measures improved after therapy, and laryngeal dysfunction improved in 7 (64%) participants.

CONCLUSION

Laryngeal dysfunction affects respiration and phonation in severe asthma. It requires identification and treatment to minimize its impact on asthma symptoms.

Developments in the field of clinical allergy in 2018 through the eyes of Clinical and Experimental Allergy, Part II

In this article, we describe developments in the field of clinical allergy as described by Clinical and Experimental Allergy in 2018; epidemiology, asthma and rhinitis, clinical allergy and allergens are all covered.

Prevalence and impact of comorbid laryngeal dysfunction in asthma: A systematic review and meta-analysis

BACKGROUND

Laryngeal or vocal cord dysfunction has long been regarded as a mimic of asthma; however, recent evidence indicates that it may be a significant comorbid condition in patients with asthma.

OBJECTIVE

We aimed to systematically estimate the prevalence of comorbid laryngeal dysfunction (LD) in adults with asthma and characterize its clinical impact on asthma.

METHODS

Electronic databases were searched for relevant studies published until June 2019. Studies were included if LD was objectively defined by direct visualization of laryngeal movement. Outcomes included the prevalence of LD and its association with clinical asthma indicators, such as severity, control, and quality of life. Random effects meta-analyses were performed to calculate the estimates.

RESULTS

A total of 21 studies involving 1637 patients were identified. Overall, the pooled prevalence of LD in adults with asthma was 25% (95% CI = 15%-37%; I² = 96%). Prevalence estimates differed according to the diagnostic test utilized, with the lowest overall prevalence (4% [95% CI = 0%-10%; I² = 90%]) seen when LD was diagnosed by resting laryngoscopy without external stimuli; however, it was much higher when diagnosed by laryngoscopy studies utilizing an external trigger, such as exercise (38% [95% CI = 24%-53%; I² = 90%]) or in studies using a computed tomography-based diagnostic protocol (36% [95% CI = 24%-49%; I² = 78%]). Only 7 studies reported the associations between LD and clinical asthma indicators; inconsistencies between studies limited meaningful conclusions.

CONCLUSION

LD may be a common comorbidity in asthma, affecting about 25% of adult patients. Further prospective studies are needed to better characterize its clinical impact and the benefits of detecting and managing LD in patients with asthma.

Systematic Assessment of Difficult-to-Treat Asthma: Principles and Perspectives

Difficult-to-treat asthma affects a minority of adults and children with asthma but represents a challenging mix of misdiagnosis, multimorbidity, inadequate self-management, severe airway pathobiology, and treatment complications. Management of these patients extends beyond asthma pharmacotherapy, because multiple other patient-related domains need to be addressed as well. Such complexity can hinder adequate clinical assessment even when performed in specialist practice. Systematic assessment undertaken by specialized multidisciplinary teams brings a broad range of resources to bear on patients with difficult-to-treat asthma. Although the concept of systematic assessment is not new, practices vary considerably and implementation is not universal. Nevertheless, assessment protocols are already in place in several institutions worldwide, and outcomes after such assessments have been highly encouraging. This review discusses the rationale, components, and benefits of systematic assessment, outlining its clinical utility and the available evidence for improved outcomes. It describes a range of service configurations and assessment approaches, drawing examples from severe asthma centers around the world to highlight common essential elements. It also provides a framework for establishing such services and discusses practical considerations for implementation.

Paradoxical Vocal Fold Motion in Difficult Asthma Is Associated with Dysfunctional Breathing and Preserved Lung Function

BACKGROUND

Many patients with difficult asthma also have coexisting vocal cord dysfunction (VCD), evident by paradoxical vocal fold motion (PVFM) on laryngoscopy.

OBJECTIVE

Among patients with difficult asthma, we sought to identify clinical features associated with laryngoscopy-diagnosed PVFM.

METHODS

Consecutive patients with "difficult asthma" referred by respiratory specialists underwent systematic assessment in this observational study. Those with a high clinical suspicion for VCD were referred for laryngoscopy, either at rest or after mannitol provocation. Statistical analyses were performed to identify clinical factors associated with PVFM, and a multivariate logistic regression model was fitted to control for confounders.

RESULTS

Of 169 patients with difficult asthma, 63 (37.3%) had a high clinical probability of VCD. Of 42 who underwent laryngoscopy, 32 had PVFM confirmed. Patients with PVFM more likely had preserved lung function (prebronchodilator forced expiratory ratio 74% ± 11 vs 62% ± 16, P < .001); physiotherapist-confirmed dysfunctional breathing (odds ratio [OR] = 5.52, 95% confidence interval [CI]: 2.4-12.7, P < .001), gastro-oesophageal reflux (OR = 2.6, 95% CI: 1.16-5.8, P = .02), and a lower peripheral eosinophil count (0.09 vs 0.23, P = .004). On multivariate logistic regression, independent predictors for PVFM were dysfunctional breathing (OR = 4.93, 95% CI: 2-12, P < .001) and preserved lung function (OR = 1.07, 95% CI: 1.028-1.106, P < .001).

CONCLUSION

Among specialist-referred patients with difficult asthma, VCD pathogenesis may overlap with dysfunctional breathing but is not associated with severe airflow obstruction. Dysfunctional breathing and preserved lung function may serve as clinical clues for the presence of VCD.

Systematic Assessment for Difficult and Severe Asthma Improves Outcomes and Halves Oral Corticosteroid Burden Independent of Monoclonal Biologic Use

BACKGROUND

Guidelines endorse systematic assessment for severe asthma, with data indicating benefit across multiple outcome domains.

OBJECTIVE

We examined which patients respond to systematic assessment and whether oral corticosteroid burden can be decreased independent of monoclonal biologic use.

METHODS

Specialist-referred patients are assessed systematically for difficult asthma at our center. We undertook a responder analysis for improvements in the domains of symptom control, quality of life, exacerbations, and airflow obstruction, assessed 6 months after initial assessment. Multivariate analyses were performed for each domain to identify predictors of response. Changes in oral corticosteroid burden were also measured, stratified by monoclonal biologics commenced during assessment.

RESULTS

Among 161 patients assessed systematically, 64% had a reduction in exacerbations, 54% achieved minimum clinically important differences for both symptom control and quality of life, and 40% increased their forced expiratory volume in 1 second by ≥100 mL. Altogether, 87% of patients with asthma improved in at least 1 domain. The most consistent predictor of response across domains was poorer baseline asthma status. There was a substantial reduction in mean chronic oral corticosteroid dose (11-5 mg, n = 46, P < .001), even after excluding 7 patients commenced on monoclonal biologics (11-5.6 mg, n = 39, P < .001).

CONCLUSIONS

Almost 90% of patients undergoing systematic assessment for difficult asthma improve significantly in at least 1 key asthma outcome, with few reliable predictors of response. The halving of oral corticosteroid burden during systematic assessment is independent of, and comparable in magnitude with, that achieved by monoclonal biologics.

Asthma

"From the Pages of AllergyWatch" is devoted to publishing synopses of Allergy and Asthma literature relevant to a topic of emphasis. These unbiased synopses and comments by our Editors have been previously printed in the AllergyWatch bimonthly newsletter, and it is our hope that presenting carefully selected article summaries and comments in the Annals will serve as a valuable educational resource for practicing allergists.

Feasibility of portable continuous laryngoscopy during exercise testing

Exercise-induced laryngeal obstruction (EILO) is a prevalent and yet still under-recognised cause of exertional breathlessness [1]. The transient closure of the larynx, which develops during EILO, results in dyspnoea, cough, inspiratory wheeze (i.e. stridor) and tightness in the throat on physical exertion. It is estimated that EILO is present in 6% of adolescents and as many as one in four athletes with unexplained respiratory symptoms [1, 2]. Despite improved recognition over the past 5 years [3, 4], it remains frequently misdiagnosed and mistreated as asthma [2, 5].

Exercise-induced laryngeal obstruction (EILO) is a prevalent problem causing exertional breathlessness and wheeze. This report demonstrates the feasibility and safety of a diagnostic approach to EILO, using a portable laryngoscope during exercise.http://ow.ly/eM6L30njDst