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

Age differences in inducible laryngeal obstruction in adult populations

BACKGROUND

Whereas differences in inducible laryngeal obstruction (ILO) presentation on the basis of age have been observed within pediatric populations, age-based differences in adult populations are lacking.

OBJECTIVE

To describe differences in ILO on the basis of age in adults.

METHODS

Patients aged older than 16 years with confirmed ILO (vocal cord adduction > 50% during inspiration) by means of provocation-challenge rhinolaryngoscopy by their treating allergist were included. An investigator-designed questionnaire was administered using Research Electronic Data Capture with corresponding medical data collection. χ2 tests, Student's t tests, analysis of variance, Cochran-Armitage test for trend, and Fisher's exact test were used.

RESULTS

The median age of the 67 patients was 50 years. P values less than .05 were considered significant. Those aged younger than 50 years (n = 31; mean age 35.6 years) reported more symptoms vs age 50 years and older (n = 36; mean age 61.8 years), including shortness of breath at rest and exertion (84% vs 39%, 94% vs 72%), throat tightness (81% vs 50%), chest tightness (81% vs 47%), and difficulty getting air in (81% vs 56%). Those aged younger than 50 years had an increased history of anxiety (68% vs 33%), asthma (55% vs 31%), positive methacholine challenge (52% vs 22%), increasing triggers with time (87% vs 43%), higher Pittsburgh Vocal Cord Dysfunction Index Scores (6.9 vs 5.5), and inspiratory curve flattening (48% vs 24%). Additional age-based subdivisions confirmed significant trends with the lowest reported ILO characteristics and symptoms in those aged 65 years and older.

CONCLUSION

A high index of suspicion for ILO should be maintained in older adults since they may report less typical ILO symptoms and anxiety associations that prompt ILO evaluation.

Economic Burden of Induced Laryngeal Obstruction in Adolescents and Children

PURPOSE

Diagnosing pediatric induced laryngeal obstruction (ILO) requires equipment typically available in specialist settings, and patients often see multiple providers before a diagnosis is determined. This study examined the financial burden associated with the diagnosis and treatment of ILO in pediatric patients with reference to socioeconomic disadvantage.

METHODS

Adolescents and children (<18 years of age) diagnosed with ILO were identified through the University of Madison Voice and Swallow Outcomes Database. Procedures, office visits, and prescribed medications were collected from the electronic medical record. Expenditures were calculated for two time periods (1) pre-diagnosis (first dyspnea-related visit to diagnosis), and (2) the first year following diagnosis. The Area Deprivation Index (ADI) was used to estimate patient socioeconomic status to determine if costs differed with neighborhood-level disadvantage.

RESULTS

A total of 113 patients met inclusion criteria (13.9 years, 79% female). Total pre-diagnosis costs of ILO averaged $6486.93 (SD = $6604.14, median = $3845.66) and post-diagnosis costs averaged $2067.69 (SD = $2322.78; median = $1384.12). Patients underwent a mean of 3.01 (SD = 1.9; median = 2) procedures and 5.8 (SD = 4.7; median = 5) office visits prior to diagnosis. Pharmaceutical, procedure/office visit, and indirect costs significantly decreased following diagnosis. Patients living in neighborhoods with greater socioeconomic disadvantage underwent fewer procedures and were prescribed more medication than those from more affluent areas. However, total expenditures did not differ based on ADI.

CONCLUSIONS

Pediatric ILO is associated with considerable financial costs. The source of these costs, however, differed according to socioeconomic advantage. Future work should determine how ILO diagnosis and management can be more efficient and equitable across all patients. Laryngoscope, 134:3384-3390, 2024.

The role of radiological imaging in the management of severe and difficult-to-treat asthma

Radiological imaging has proven to be a useful tool in the assessment of asthma, its comorbidities and potential complications. Characteristic chest radiograph and computed tomography scan findings can be seen in asthma and in other conditions that can coexist with or be misdiagnosed as asthma, including chronic rhinosinusitis, inducible laryngeal obstruction, excessive dynamic airway collapse, tracheobronchomalacia, concomitant COPD, bronchiectasis, allergic bronchopulmonary aspergillosis, eosinophilic granulomatosis with polyangiitis, and eosinophilic pneumonia. The identification of the characteristic radiological findings of these conditions is often essential in making the correct diagnosis and provision of appropriate management and treatment. Furthermore, radiological imaging modalities can be used to monitor response to therapy.

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.

Patients' Demographics and Risk Factors in Voice Disorders: An Umbrella Review of Systematic Reviews

OBJECTIVES

This study aimed to provide a comprehensive overview of the systematic reviews that focus on the prevalence of voice disorders (VDs), associated risk factors, and the demographic characteristics of patients with dysphonia. An umbrella review was conducted to identify general research themes in voice literature that might guide future research initiatives and contribute to the classification of VDs as a worldwide health concern.

STUDY DESIGN

Umbrella review of systematic reviews.

METHODS

Pubmed/Medline and Embase were searched for eligible systematic reviews by two authors independently. Extracted data items included the study publication details, study design, characteristics of the target population, sample size, region/country, and incidence and/or prevalence of the VD(s) of interest.

RESULTS

Forty systematic reviews were included. Sixteen reported a meta-analysis. Great heterogeneity in methods was found. A total of 277,035 patients across the included studies were included with a prevalence ranging from 0%-90%. The countries represented best were the United States and Brazil, with 13 studies each. Aging, occupational voice use, lifestyle choices, and specific comorbidities, such as obesity or hormonal disorders, seem to be associated with an increased prevalence of dysphonia.

CONCLUSIONS

This review underscores the influence of VDs on distinct patient groups and the general population. A variety of modifiable or non-modifiable risk factors, having varied degrees of impact on voice qualities, have been identified. The overall effect of VDs is probably underestimated due to factors, such as sample size, patient selection, underreporting of symptoms, and asymptomatic cases. Employing systematic reviews with consistent methodologies and criteria for diagnosing VDs would enhance the ability to determine the prevalence of VDs and their impact.

Prevalence and characterisation of exercise-induced laryngeal obstruction in patients with exercise-induced dyspnoea

OBJECTIVE

The prevalence of exercise-induced laryngeal obstruction is largely unknown. This study aimed to evaluate the prevalence of this condition in a selected study population of patients with exercise-induced dyspnoea.

METHOD

A retrospective analysis was conducted of demographic data, co-morbidities, medication, symptoms, performance level of sporting activities, continuous laryngoscopy exercise test results and subsequent treatment.

RESULTS

Data from 184 patients were analysed. The overall prevalence of exercise-induced laryngeal obstruction in the study population was 40 per cent, and the highest prevalence was among females aged under 18 years (61 per cent). However, a high prevalence among males aged under 18 years (50 per cent) and among adults regardless of gender (34 per cent) was also found.

CONCLUSION

The prevalence of exercise-induced laryngeal obstruction is clinically relevant regardless of age and gender. Clinicians are encouraged to consider exercise-induced laryngeal obstruction as a possible diagnosis in patients suffering from exercise-induced respiratory symptoms. No single characteristic that can distinguish exercise-induced laryngeal obstruction from other similar conditions was identified.

Untangling asthma, inducible laryngeal obstruction, and dysfunctional breathing in a competitive sportsperson

A young woman with historically mild asthma experienced worsening breathlessness and cough with competitive ice skating. Despite optimizing and escalating treatment for her eosinophilic asthma, and addressing known exacerbating factors, her symptoms remained uncontrolled and refractory to bronchodilators and oral corticosteroids. Objective testing suggested her presentation was out of keeping with asthma alone, and she was suspected to have comorbid dysfunctional breathing and/or inducible laryngeal obstruction. Evidence was required to confirm the diagnoses, assess each condition's contribution to her symptom burden, and guide therapy. As exercise was a predominant trigger, she proceeded to cardiopulmonary exercise test with continuous laryngoscopy during exercise (CPET-CLE). Testing confirmed the presence of two forms of inducible laryngeal obstruction and evidence of hyperventilation predominant dysfunctional breathing. This case highlights the importance of identifying coexisting conditions in difficult-to-treat asthma, and the value of structured multidisciplinary assessment in referral centres for such individuals.

Treatable traits in asthma during pregnancy: a call for a shift towards a precision-based management approach

Asthma is the most common chronic medical condition in pregnancy. Asthma exacerbations in pregnancy are unpredictable, and are associated with adverse maternal and fetal perinatal outcomes such as preterm birth and low birthweight. Goals of asthma management in pregnancy are to establish effective asthma control and prevent exacerbations. Optimising the management of asthma in pregnancy is an important goal of practice and future research.Treatable traits is a precision medicine paradigm proposed for the management of airways diseases, which holistically addresses the complexity and heterogeneity of airways disease. It is an individualised treatment approach that aims to improve outcomes. This makes treatable traits well suited for pregnant women with asthma, who have a high prevalence of obesity, mental health conditions, poor symptom perception and suboptimal asthma management skills including low treatment adherence. These traits are measurable and treatable. In this review, we explore current knowledge on the burden of asthma, maternal and perinatal consequences of asthma during pregnancy, the treatable traits paradigm, the prevalence of treatable traits in pregnant women with asthma, and consider how the treatable traits paradigm can be integrated into the management of asthma in pregnancy.

The Clinical Utility of Continuous Laryngoscopy During Exercise: A Report of Two Cases

Exertional dyspnea is a common and disabling symptom in otherwise healthy children and adolescents, as well as in children with baseline airway abnormalities. It impairs the quality of life and may be associated with fatigue and underperformance in sports. Exertional dyspnea can be caused by a wide variety of structural and psychogenic causes. Exercise-induced laryngeal obstruction (EILO) is a relatively prevalent entity in young people that usually presents with exertional stridor, coughing, and dyspnea caused by transient closure of the larynx. In more complex cases where conventional tests such as pulmonary function tests (PFTs), chest imaging, ECG, and echocardiography are unrevealing, continuous laryngoscopy during exercise (CLE) tests may provide diagnostic utility. In addition to the baseline abnormalities visualized by conventional laryngoscopy, CLE can assess dynamic laryngeal responses during exercise. This article describes the clinical characteristics of two pediatric patients with various degrees of laryngeal dysfunction at baseline and the utility of CLE testing in tailoring management strategies.

Diagnosis of vocal cord dysfunction/inducible laryngeal obstruction: An International Delphi Consensus Study

BACKGROUND

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathing difficulties in association with excessive supraglottic or glottic laryngeal narrowing. The condition is common and can occur independently; however, it may also be comorbid with other disorders or mimic them. Presentations span multiple specialties and misdiagnosis or delayed diagnosis is commonplace. Group-consensus methods can efficiently generate internationally accepted diagnostic criteria and descriptions to increase clinical recognition, enhance clinical service availability, and catalyze research.

OBJECTIVES

We sought to establish consensus-based diagnostic criteria and methods for VCD/ILO.

METHODS

We performed a modified 2-round Delphi study between December 7, 2021, and March 14, 2022. The study was registered at ANZCTR (Australian New Zealand Clinical Trials Registry; ACTRN12621001520820p). In round 1, experts provided open-ended statements that were categorized, deduplicated, and amended for clarity. These were presented to experts for agreement ranking in round 2, with consensus defined as ≥70% agreement.

RESULTS

Both rounds were completed by 47 international experts. In round 1, 1102 qualitative responses were received. Of the 200 statements presented to experts across 2 rounds, 130 (65%) reached consensus. Results were discussed at 2 international subject-specific conferences in June 2022. Experts agreed on a diagnostic definition for VCD/ILO and endorsed the concept of VCD/ILO phenotypes and clinical descriptions. The panel agreed that laryngoscopy with provocation is the gold standard for diagnosis and that ≥50% laryngeal closure on inspiration or Maat grade ≥2 define abnormal laryngeal closure indicative of VCD/ILO.

CONCLUSIONS

This Delphi study reached consensus on multiple aspects of VCD/ILO diagnosis and can inform clinical practice and facilitate research.

Cough and cough hypersensitivity as treatable traits of asthma

Cough is a common and troublesome symptom in people with asthma and is often associated with poorer asthma control and exacerbations. Apart from asthma, other causes or comorbidities might underlie cough in asthma, such as rhinosinusitis and bronchiectasis. Eosinophilic inflammation and bronchoconstriction can lead to an acute episode of cough or worsen chronic cough. Cough hypersensitivity with laryngeal paraesthesia, allotussia, and hypertussia might underlie the cough of asthma through augmented sensory nerve excitability of upper-airway vagal sensory nerves. Cough associated with bronchoconstriction and type 2 inflammation should respond to inhaled corticosteroids and long-acting β-adrenoceptor agonist therapy. For cough hypersensitivity in adults, speech and language therapy and neuromodulators (eg, gabapentin) could be considered. In children, there is no consistent association of asthma with cough sensitivity or between cough and asthma severity. Further research is needed to realise the potential of cough as a measure of asthma control, to understand the mechanisms of cough in asthma, and to develop safe, effective treatments and a precision-medicine approach to the management of cough in asthma in children and adults.

Vocal cord dysfunction/inducible laryngeal obstruction-2022 Melbourne Roundtable Report

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO), is a common condition characterized by breathlessness associated with inappropriate laryngeal narrowing. Important questions remain unresolved, and to improve collaboration and harmonization in the field, we convened an international Roundtable conference on VCD/ILO in Melbourne, Australia. The aims were to delineate a consistent approach to VCD/ILO diagnosis, appraise disease pathogenesis, outline current management and model(s) of care and identify key research questions. This report summarizes discussions, frames key questions and details recommendations. Participants discussed clinical, research and conceptual advances in the context of recent evidence. The condition presents in a heterogenous manner, and diagnosis is often delayed. Definitive diagnosis of VCD/ILO conventionally utilizes laryngoscopy demonstrating inspiratory vocal fold narrowing >50%. Computed tomography of the larynx is a new technology with potential for swift diagnosis that requires validation in clinical pathways. Disease pathogenesis and multimorbidity interactions are complex reflecting a multi-factorial, complex condition, with no single overarching disease mechanism. Currently there is no evidence-based standard of care since randomized trials for treatment are non-existent. Recent multidisciplinary models of care need to be clearly articulated and prospectively investigated. Patient impact and healthcare utilization can be formidable but have largely escaped inquiry and patient perspectives have not been explored. Roundtable participants expressed optimism as collective understanding of this complex condition evolves. The Melbourne VCD/ILO Roundtable 2022 identified clear priorities and future directions for this impactful condition.

Trigeminal Function in Sino-Nasal Health and Disease

The upper airway (nasal passages, paranasal sinuses, pharynx, and glottis) provides the sentinel portion of the human respiratory tract, with the combined senses of olfaction (cranial nerve I) and trigeminal sensation (cranial nerve V) signaling the quality of inspired air. Trigeminal function also complements the sense of taste (in turn mediated by cranial nerves VII, IX and X), and participates in the genesis of taste aversions. The ability of trigeminal stimulation in the upper aero-digestive tract to trigger a variety of respiratory and behavioral reflexes has long been recognized. In this context, the last three decades has seen a proliferation of observations at a molecular level regarding the mechanisms of olfaction, irritation, and gustation. Concurrently, an ever-widening network of physiological interactions between olfaction, taste, and trigeminal function has been uncovered. The objective of this review is to summarize the relatively recent expansion of research in this sub-field of sensory science, and to explore the clinical and therapeutic implications thereof.

Prevalence and impact of exercise-induced laryngeal obstruction in asthma: a study protocol for a cross-sectional and longitudinal study

INTRODUCTION

Exercise-induced laryngeal obstruction (EILO) and exercise-induced asthma can cause troublesome respiratory symptoms that can be difficult to distinguish between. Further, there is now a growing appreciation that the two conditions may coexist, complicating the interpretation of symptoms. The primary aim of this study is to investigate the prevalence of EILO in patients with asthma. Secondary aims include evaluation of EILO treatment effects and investigation of comorbid conditions other than EILO in patients with asthma.

METHODS AND ANALYSIS

The study will be conducted at Haukeland University Hospital and Voss Hospital in Western Norway, and enrol 80-120 patients with asthma and a control group of 40 patients without asthma. Recruitment started in November 2020, and data sampling will continue until March 2024. Laryngeal function will be assessed at baseline and at a 1-year follow-up, using continuous laryngoscopy during high-intensity exercise (CLE). Immediately after the EILO diagnosis is verified, patients will be treated with standardised breathing advice guided by visual biofeedback from the laryngoscope video screen. The primary outcome will be the prevalence of EILO in patients with asthma and control participants. Secondary outcomes include changes in CLE scores, asthma-related quality of life, asthma control and number of the asthma exacerbations, as assessed between baseline and the 1-year follow-up.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Regional Committee for Medical and Health Research Ethics, Western Norway, (ID number 97615). All participants will provide signed informed consent before enrolment. The results will be presented in international journals and conferences.

TRIAL REGISTRATION NUMBER

NCT04593394.

Predictors of voice therapy efficacy in vocal cord dysfunction at a tertiary care center

OBJECTIVE

Vocal cord dysfunction is inappropriate adduction of vocal cords during inspiration that causes dyspnea and is commonly mistaken for exercise-induced asthma. To improve diagnostic accuracy, this study aims to identify demographics associated with vocal cord dysfunction and to determine their impact on the efficacy of voice therapy in improving vocal cord function.

STUDY DESIGN

Retrospective chart review.

SETTING

Single tertiary care institution between January 2015 and December 2021.

METHODS

184 patients who underwent voice therapy for vocal cord dysfunction were included. The primary outcome was patient self-reported percent improvement of symptoms. The secondary outcome was number of voice therapy treatments.

RESULTS

The mean duration of symptoms was 2 ± 3 years. The mean number of voice therapy treatments was 2.2 ± 1.5. Of the 107 (58.2 %) patients with documented perceived breathing improvement percentages recorded, the mean maximal percent improvement was 72.5 ± 21.5 %. Mean maximal percent improvement of symptoms increased with each voice therapy treatment (p = 0.01). This association remained significant when controlling for comorbid conditions such as allergic rhinitis with postnasal drip, anxiety, asthma, and gastroesophageal reflux disease in multivariate analysis (p = 0.005). Patients with asthma had significantly higher maximum percent breathing improvement compared to those without asthma (p = 0.026). Similarly, patients who played sports had significantly higher maximum percent breathing improvement compared to those who did not (p = 0.022).

CONCLUSION

Patient perceived breathing improvement with voice therapy is higher among those with concomitant asthma and those who play sports. Voice therapy is a safe and effective first line treatment of vocal cord dysfunction even when controlling for comorbid conditions.

Strength of association between comorbidities and asthma: a meta-analysis

BACKGROUND

The strength of association between comorbidities and asthma has never been ranked in relation to the prevalence of the comorbidity in the nonasthma population. We investigated the strength of association between comorbidities and asthma.

METHODS

A comprehensive literature search was performed for observational studies reporting data on comorbidities in asthma and nonasthma populations. A pairwise meta-analysis was performed and the strength of association calculated by anchoring odds ratios and 95% confidence intervals with the rate of comorbidities in nonasthma populations via Cohen's d method. Cohen's d=0.2, 0.5 and 0.8 were cut-off values for small, medium and large effect sizes, respectively; very large effect size resulted for Cohen's d >0.8. The review was registered in the PROSPERO database; identifier number CRD42022295657.

RESULTS

Data from 5 493 776 subjects were analysed. Allergic rhinitis (OR 4.24, 95% CI 3.82-4.71), allergic conjunctivitis (OR 2.63, 95% CI 2.22-3.11), bronchiectasis (OR 4.89, 95% CI 4.48-5.34), hypertensive cardiomyopathy (OR 4.24, 95% CI 2.06-8.90) and nasal congestion (OR 3.30, 95% CI 2.96-3.67) were strongly associated with asthma (Cohen's d >0.5 and ≤0.8); COPD (OR 6.23, 95% CI 4.43-8.77) and other chronic respiratory diseases (OR 12.85, 95% CI 10.14-16.29) were very strongly associated with asthma (Cohen's d >0.8). Stronger associations were detected between comorbidities and severe asthma. No bias resulted according to funnel plots and Egger's test.

CONCLUSION

This meta-analysis supports the relevance of individualised strategies for disease management that look beyond asthma. A multidimensional approach should be used to assess whether poor symptom control is related to uncontrolled asthma or to uncontrolled underlying comorbidities.

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.

Computed Tomography Imaging of the Larynx for Diagnosis of Vocal Cord Dysfunction

BACKGROUND: Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathlessness and often mimics or accompanies severe asthma. The disorder occurs intermittently, and the diagnosis is established by using laryngoscopy. Dynamic computed tomography (CT) imaging of the larynx at low-radiation doses has the potential to provide an alternative method to make the diagnosis of VCD/ILO. METHODS: We report two case series: in series A, laryngoscopy (diagnostic standard) and CT imaging of the larynx were each performed within 1 hour of each other (n=31), and in series B, the procedures were performed on separate days 4 to 6 weeks apart (n=72). Diagnosis of VCD/ILO by laryngoscopy used conventional criteria, and diagnosis by CT imaging was based on vocal cord narrowing in excess of a validated normal threshold. In each series, we evaluated the accuracy of CT imaging of the larynx to establish a diagnosis of VCD/ILO compared with laryngoscopy. RESULTS: In series A, the sensitivity of CT imaging of the larynx was 53.8%, and specificity was 88.9%; in series B, the sensitivity of CT imaging of the larynx was 76.2%, and specificity was 93.3%. At a disease prevalence of 30% (which was known to be the case in our clinic), the positive predictive value was 67.5% in series A and 83% in series B. Negative predictive values were 81.8% and 90.1% in series A and B, respectively, and false-positive rates were 11.1% and 6.7%. CONCLUSIONS: When the population prevalence was assumed to be 30%, low-dose CT imaging of the larynx detected VCD/ILO with negative predictive values greater than 80% in both series settings and agreed with each other within 9 percentage points. Positive predictive values for laryngeal CT imaging varied substantially between the settings of the two case series. (Supported by Monash Lung and Sleep Institute and Grant APP ID 1198362 and others.)

Vocal cord dysfunction/inducible laryngeal obstruction: novel diagnostics and therapeutics

INTRODUCTION

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is an important medical condition but understanding of the condition is imperfect. It occurs in healthy people but often co-exists with asthma. Models of VCD/ILO pathophysiology highlight predisposing factors rather than specific mechanisms and disease expression varies between people, which is seldom appreciated. Diagnosis is often delayed, and the treatment is not evidence based.

AREAS COVERED

A unified pathophysiological model and disease phenotypes have been proposed. Diagnosis is conventionally made by laryngoscopy during inspiration with vocal cord narrowing >50% Recently, dynamic CT larynx was shown to have high specificity (>80%) with potential as a noninvasive, swift, and quantifiable diagnostic modality. Treatment entails laryngeal retraining with speech pathology intervention and experimental therapies such as botulinum toxin injection. Multidisciplinary team (MDT) clinics are a novel innovation with demonstrated benefits including accurate diagnosis, selection of appropriate treatment, and reductions in oral corticosteroid exposure.

EXPERT OPINION

Delayed diagnosis of VCD/ILO is pervasive, often leading to detrimental treatments. Phenotypes require validation and CT larynx can reduce the necessity for laryngoscopy, thereby fast-tracking diagnosis. MDT clinics can optimize management. Randomized controlled trials are essential to validate speech pathology intervention and other treatment modalities and to establish international standards of care.

Respiratory comorbidities in severe asthma: focus on the pediatric age

INTRODUCTION

Asthma comorbidities are a frequent cause of adverse outcomes, such as poor asthma control, frequent asthma attacks, reduced quality of life, and higher healthcare costs. Comorbidities are well-known treatable traits whose proper management can help achieve optimal asthma control. Although multimorbidity is frequent among asthmatics, comorbidities are still a potential cause of misdiagnosis and under or over treatments, and little is known about their impact on severe pediatric asthma.

AREAS COVERED

We provided a comprehensive, 5-year updated review focusing on the main respiratory comorbidities in severe asthma, particularly in epidemiology, pathogenesis, and current and future therapies.

EXPERT OPINION

Respiratory comorbidities have unique characteristics in childhood. Their management must be multidisciplinary, age-specific, and integrated. Further longitudinal studies are needed to understand better the mutual interrelation and synergistic effect between asthma and its respiratory comorbidities, the identification of common, treatable risk factors leading to potential asthma prevention, the effectiveness of actual and future target-therapies, and the correlation between long-lasting respiratory comorbidities and poor lung function trajectories.

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.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

Clinical Characteristics of Irritant-Induced Occupational Asthma

BACKGROUND

Work is a substantial contributing factor of adult-onset asthma. A subtype of occupational asthma (OA) is caused by irritant agents, but knowledge of the clinical outcomes of irritant-induced asthma (IIA) is incomplete.

OBJECTIVES

To evaluate whether the clinical picture of IIA differs from that of sensitizer-induced OA.

METHODS

This retrospective study analyzed acute and subacute IIA patients diagnosed in an occupational medicine clinic during 2004 to 2018. Sixty-nine patients fulfilled the inclusion criteria, and their characteristics were analyzed at the time of the diagnosis and 6 months later. The results were compared with those of 2 subgroups of sensitizer-induced OA: 69 high-molecular-weight (HMW) and 89 low-molecular-weight (LMW) agent-induced OA patients.

RESULTS

Six months after the diagnosis, 30% of the patients with IIA needed daily short-acting β-agonists (SABA), 68% were treated with Global Initiative for Asthma, 2020 report (GINA) step 4-5 medication, and 24% of the patients had asthma exacerbation after the first appointment. IIA depicted inferiority to LMW-induced OA in daily need for SABA (odds ratio [OR]: 3.80, 95% confidence interval [CI]: 1.38-10.46), treatment with GINA step 4-5 medication (OR: 2.22, 95% CI: 1.08-4.57), and exacerbation (OR: 3.85, 95% CI: 1.35-11.04). IIA showed poorer results than HMW-induced OA in the latter 2 of these features (OR: 2.49, 95% CI: 1.07-5.79 and OR: 6.29, 95% CI: 1.53-25.83, respectively).

CONCLUSIONS

Six months after the OA diagnosis, a significant proportion of the patients with IIA remain symptomatic and the majority of these patients use asthma medications extensively suggesting uncontrolled asthma. The short-term outcomes of IIA appear poorer than that of sensitizer-induced OA.

Evolving Concept of Severe Asthma: Transition From Diagnosis to Treatable Traits

In recent decades, the concept of severe asthma has evolved from an umbrella term encompassing patients with high-intensity treatment needs to a clinical syndrome with heterogeneous, albeit distinct, pathophysiological processes. Biased and unbiased cluster approaches have been used to identify several clinical phenotypes. In parallel, cellular and molecular approaches allow for the development of biological therapies, especially targeting type 2 (T2) cytokine pathways. Although T2-biologics have significantly improved clinical outcomes for patients with severe asthma in real-world practice, questions on the proper use of biologics remain open. Furthermore, a subset of severe asthma patients remains poorly controlled. The unmet needs require a new approach. The “treatable traits” concept has been suggested to address a diversity of pathophysiological factors in severe asthma and overcome the limitations of existing treatment strategies. With a tailored therapy that targets the treatable traits in individual patients, better personalized medical care and outcomes should be achieved.

Treatable Traits in Chronic Respiratory Disease: A Comprehensive Review

Chronic respiratory diseases are major contributors to the global burden of disease. While understanding of these diseases has improved, treatment guidelines have continued to rely on severity and exacerbation-based approaches. A new personalised approach, termed the "treatable traits" approach, has been suggested to address the limitations of the existing treatment strategies. We aim to systematically review the current evidence regarding treatable traits in chronic respiratory diseases and to identify gaps in the current literature. We searched the PubMed and Embase databases and included studies on treatable traits and chronic respiratory diseases. We then extracted information on prevalence, prognostic implications, treatment options and benefits from these studies. A total of 58 papers was included for review. The traits identified were grouped into five broad themes: physiological, biochemical, psychosocial, microbiological, and comorbidity traits. Studies have shown advantages of the treatable traits paradigm in the clinical setting. However, few randomised controlled trials have been conducted. Findings from our review suggest that multidisciplinary management with therapies targeted at treatable traits has the potential to be efficacious when added to the best practices currently implemented. This paradigm has the potential to improve the holistic care of chronic respiratory diseases.

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.

Clinical Findings among Patients with Respiratory Symptoms Related to Moisture Damage Exposure at the Workplace-The SAMDAW Study

BACKGROUND

Respiratory tract symptoms are associated with workplace moisture damage (MD). The focus of this observational clinical study was patients with workplace MD-associated symptoms, to evaluate the usefulness of different clinical tests in diagnostics in secondary healthcare with a special interest in improving the differential diagnostics between asthma and laryngeal dysfunction.

METHODS

In patients referred because of workplace MD-associated respiratory tract symptoms, we sought to systematically assess a wide variety of clinical findings.

RESULTS

New-onset asthma was diagnosed in 30% of the study patients. Laryngeal dysfunction was found in 28% and organic laryngeal changes in 22% of the patients, and these were common among patients both with and without asthma. Most of the patients (85%) reported a runny or stuffy nose, and 11% of them had chronic rhinosinusitis. Atopy was equally as common as in the general population.

CONCLUSIONS

As laryngeal changes were rather common, we recommend proper differential diagnostics with lung function testing and investigations of the larynx and its functioning, when necessary, in cases of prolonged workplace MD-associated symptoms. Chronic rhinosinusitis among these patients was not uncommon. Based on this study, allergy testing should not play a major role in the examination of these patients.

Characteristics and impact of exercise-induced laryngeal obstruction: an international perspective

Background

Exercise-induced laryngeal obstruction (EILO) is a common cause of exertional breathlessness and wheeze yet is frequently misdiagnosed as asthma. Insight regarding the demographic characteristics, laryngeal abnormalities and impact of EILO is currently limited, with data only available from individual centre reports. The aim of this work was to provide a broader perspective from a collaboration between multiple international expert centres.

Methods

Five geographically distinct clinical paediatric and adult centres (3 Denmark, 1 UK, 1 USA) with an expertise in assessing unexplained exertional breathlessness completed database entry of key characteristic features for all cases referred with suspected EILO over a 5-year period. All included cases completed clinical asthma workup and continuous laryngoscopy during exercise (CLE) testing for EILO.

Results

Data were available for 1007 individuals (n=713 female (71%)) with a median (range) age of 24 (8–76) years, and of these 586 (58%) were diagnosed with EILO. In all centres, EILO was frequently misdiagnosed as asthma; on average there was a 2-year delay to diagnosis of EILO, and current asthma medication was discontinued in 20%. Collapse at the supraglottic level was seen in 60%, whereas vocal cord dysfunction (VCD) was only detected/visualised in 18%. Nearly half (45%) of individuals with EILO were active participants in recreational-level sports, suggesting that EILO is not simply confined to competitive/elite athletes.

Conclusion

Our findings indicate that key clinical characteristics and the impact of EILO/VCD are similar in globally distinct regions, facilitating improved awareness of this condition to enhance recognition and avoid erroneous asthma treatment.

Exercise-induced laryngeal obstruction is a prevalent cause of exertional breathlessness and wheeze. In this international multicentre collaboration, 1007 patients waited, on average, 2 years for diagnosis and 20% were mistreated as asthmatic.https://bit.ly/3auXpcp

Uncontrolled Asthma: Unmet Needs in the Management of Patients

The recent scientific research has provided clinicians with the tools for substantially upgrading the standard of care in the field of bronchial asthma. Nevertheless, satisfactory asthma control still remains an unmet need worldwide. Identifying the major determinants of poor control in different asthma severity levels represents the first step towards the improvement of the overall patients' management. The present review aims to provide an overview of the main unmet needs in asthma control and of the potential tools for overcoming the issue. Implementing a personalized medicine approach is essential, not only in terms of pharmacological treatments, biologic drugs or sophisticated biomarkers. In fact, exploring the complex profile of each patient, from his inflammation phenotype to his preferences and expectations, may help in filling the gap between the big potential of currently available treatments and the overall unsatisfactory asthma control. Telemedicine and e-health technologies may provide a strategy to both optimize disease assessment on a regular basis and enhance patients' empowerment in managing their asthma. Increasing patients' awareness as well as the physicians' knowledge about asthma phenotypes and treatment options besides corticosteroid probably represent the key and more difficult goals of all the players involved in asthma management at every level.

Prevalence and impact of comorbid obstructive sleep apnoea in diffuse parenchymal lung diseases

Objective

Obstructive sleep apnea (OSA) are increasingly recognized as important features in diffuse parenchymal lung diseases (DPLDs) with differed prevalence and impact reported. The aim of this study is to systematically review the prevalence of comorbid OSA and characterize its impact on clinical and outcome measurements in adults with DPLDs.

Methods

Publications addressing the prevalence of OSA in DPLDs and its impacts on DPLDs were selected from electronic databases. A random-effect model was used to estimate the pooled prevalence of OSA. Odds ratios (ORs) or mean differences (MDs) were used to assess the associations of OSA with clinical and outcome measurements. Heterogeneity was quantified by I² with 95% confidence interval (95% CI).

Results

4 studies comprising 643 participants were included. Overall, the pooled prevalence of OSA among DPLDs was 72% (95% CI: 65–79%; I² = 75.4%). Moderate-severe OSA was observed in 40% patients (95% CI: 28–52%; I² = 90.8%). The prevalence was higher as 76% in idiopathic pulmonary fibrosis (IPF) patients than in connective tissue associated-ILD or sarcoidosis (60%). Although oxygen desaturation during sleep was greater in OSA group compared with non-OSA patients, there was no difference in lung function or systematic comorbidities between the two groups. The associations between OSA and the mortality or disease progression of DPLDs were also systematically reviewed.

Conclusion

In conclusion, OSA is a common comorbidity in DPLD patients, affecting approximately three in four patients, which may exacerbate the nocturnal desaturation and have negative influence on the outcomes. Larger studies with more homogeneous samples are warranted.

Treatment options in type-2 low asthma

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30-50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, "type-2 low" asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

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.

Triggers of breathlessness in inducible laryngeal obstruction and asthma

BACKGROUND

Inducible laryngeal obstruction (ILO) is often misdiagnosed as, or may coexist with, asthma. Identifying differences in triggering factors may assist clinicians to differentiate between the two conditions and could give mechanistic insights.

OBJECTIVE

To identify and compare patient-reported triggers in ILO and asthma.

METHODS

This was a two-part study. Initially, we conducted a retrospective case note review of the triggers of ILO from endoscopically confirmed ILO patients to generate a Breathlessness Triggers Survey (BrTS). Triggers were categorized as scents, environmental factors, temperature, emotions, mechanical factors and daily activities. Secondly, ILO and/or asthma patients completed the BrTS prospectively, rating the likelihood of each item triggering their symptoms using a five-point Likert scale (strongly disagree to strongly agree). Chi-square testing was performed to compare responses by cohort.

RESULTS

Data from 202 patients with ILO [73% female, mean (SD) age 53(16) years] were included in the case note review. For the prospective study, 38 patients with ILO only [63% females, age 57(16) years], 39 patients with asthma only [(56% female, age 53(13) years] and 12 patients with both ILO and asthma [83% female, mean age, 57 (14) years)] completed the BrTS. The triggers identified in the case note review were confirmed in the independent sample of patients with ILO and/or asthma and identified several difference in prevalence of the triggers between disease types. Mechanical factors (talking [P < .001], shouting [P = .007] and swallowing [P = .002]) were more common in the ILO cohort compared to patients with asthma. Environmental factors (pollen/flowers [P = .005] and damp air [P = .012]) were more common in asthma. There were no differences between groups in frequency of reporting scents as triggers (except for vinegar, more common in ILO, P = .019), temperature, emotions or daily activities.

CONCLUSION

There were notable differences between patient-reported triggers of ILO and asthma, which may support clinician differential diagnosis.

Is the healthy respiratory system built just right, overbuilt, or underbuilt to meet the demands imposed by exercise?

In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O₂ transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an "underbuilt" respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.

Pediatric Dysfunctional Breathing: Proposed Components, Mechanisms, Diagnosis, and Management

Dysfunctional breathing (DB) is an overarching term describing deviations in the normal biomechanical patterns of breathing which have a significant impact on quality of life, performance and functioning. Whilst it occurs in both children and adults, this article focuses specifically on children. DB can be viewed as having two components; breathing pattern disorder (BPD) and inducible laryngeal obstruction (ILO). They can be considered in isolation, however, are intricately related and often co-exist. When both are suspected, we propose both BPD and ILO be investigated within an all-encompassing multi-disciplinary dysfunctional breathing clinic. The MDT clinic can diagnose DB through expert history taking and a choice of appropriate tests/examinations which may include spirometry, breathing pattern analysis, exercise testing and laryngoscopic examination. Use of the proposed algorithm presented in this article will aid decision making regarding choosing the most appropriate tests and understanding the diagnostic implications of these tests. The most common symptoms of DB are shortness of breath and chest discomfort, often during exercise. Patients with DB typically present with normal spirometry and an altered breathing pattern at rest which is amplified during exercise. In pediatric ILO, abnormalities of the upper airway such as cobblestoning are commonly seen followed by abnormal activity of the upper airway structures provoked by exercise. This may be associated with a varying degree of stridor. The symptoms, however, are often misdiagnosed as asthma and the picture can be further complicated by the common co-presentation of DB and asthma. Associated conditions such as asthma, extra-esophageal reflux, rhinitis, and allergy must be treated appropriately and well controlled before any directed therapy for DB can be started if therapy is to be successful. DB in pediatrics is commonly treated with a course of non-pharmaceutical therapy. The therapy is provided by an experienced physiotherapist, speech and language therapist or psychologist depending on the dominant features of the DB presentation (i.e., BPD or ILO in combination or in isolation) and some patients will benefit from input from more than one of these disciplines. An individualized treatment program based on expert assessment and personalized goals will result in a return to normal function with reoccurrence being rare.