Paradoxical vocal fold motion dysfunction in asthma patients

Diagnostic utility of spirometry for children with induced laryngeal obstruction or chronic non-specific cough

PURPOSE

To determine the diagnostic utility of spirometry in distinguishing children with Induced Laryngeal Obstruction (ILO) or chronic non-specific cough (a.k.a. tic cough) from those with mild or moderate to severe asthma.

METHODS

Retrospective cross sectional design. Children diagnosed with ILO (N = 70), chronic non-specific cough (N = 70), mild asthma (N = 60), or moderate to severe asthma (N = 60) were identified from the electronic medical record of a large children's hospital. Spirometry was completed before ILO, non-specific cough, or asthma diagnoses were made by pediatric laryngologists or pulmonologists. Spirometry was performed following American Thoracic Society guidelines and was interpreted by a pediatric pulmonologist. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1), FEV1/FVC Ratio (FEV1/FVC), Forced Mid-Expiratory Flow 25--75 % (FEF25-75%), pulmonologist interpretation of flow volume loops, and overall exam findings were extracted from the medical record.

RESULTS

Ninety seven percent of children with ILO or chronic non-specific cough presented with spirometry values within normative range. Patients with ILO, non-specific cough, and mild asthma presented with FVC, FEV1, FEV1/FVC, and FEF25-75% values in statistically similar range. Children with moderate to severe asthma presented with significantly reduced FVC (p < .001), FEV1 (p < .001), FEV1/FVC (p < .001), and FEF25-75% (p < .001) values when compared with patients in the other groups. Flow volume loops were predominantly normal for children with ILO and non-specific cough.

CONCLUSIONS

Findings indicate that ILO and chronic non-specific cough can neither be diagnosed nor differentiated from mild asthma using spirometry alone. Spirometry should therefore be used judiciously with this population, bearing in mind the limitations of the procedure. Future research should determine the most effective and efficient ways of delineating ILO and non-specific cough from other respiratory conditions in children.

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.

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.

Experiences of Diagnosis, Symptoms, and Use of Reliever Inhalers in Patients With Asthma and Concurrent Inducible Laryngeal Obstruction or Breathing Pattern Disorder: Qualitative Analysis of a UK Asthma Online Community

BACKGROUND

Breathing pattern disorders (BPDs) and inducible laryngeal obstruction (ILO) cause similar symptoms to asthma, including dyspnea and chest tightness, with an estimated prevalence of up to one-fifth of patients with asthma. Both conditions can be comorbid with asthma, and there is evidence that they are misdiagnosed and mistreated as asthma.

OBJECTIVE

This study aims to explore whether the symptoms of ILO and BPD were topics of discussion in a UK asthma online health community and patient experiences of diagnosis and treatment, in particular their use of reliever inhalers.

METHODS

A qualitative thematic analysis was performed with posts from an asthma community between 2018 and 2022. A list of key ILO or BPD symptoms was created from the literature. Posts were identified using the search terms "blue inhaler" and "breath" and included if describing key symptoms. Discussion threads of included posts were also analyzed.

RESULTS

The search retrieved a total of 1127 relevant posts: 1069 written by 302 users and 58 posted anonymously. All participants were adults, except 2 who were parents writing about their children. Sex and age were only available for 1.66% (5/302; 3 females and 2 males) and 9.93% (30/302) of participants (27 to 73 years old), respectively. The average number of posts written by each participant was 3.54 (range 1-63). Seven participants wrote >20 posts each. Participants experiencing undiagnosed ILO or BPD symptoms, whether or not comorbid with asthma, expressed frustration with the "one-size-fits-all" approach to diagnosis, as many felt that their asthma diagnosis did not fully explain symptoms. Some suspected or were formally diagnosed with BPD or ILO, the latter reporting relief on receiving a diagnosis and appropriate management. Participants showed awareness of their inappropriate salbutamol use or overuse due to lack of effect on symptoms. BPD and ILO symptoms were frequently comorbid with asthma. The asthma online community was a valuable resource: engagement with peers not only brought comfort but also prompted action with some going back to their clinicians and reaching a diagnosis and appropriate management.

CONCLUSIONS

Undiagnosed ILO and BPD symptoms and lack of effects of asthma treatment were topics of discussion in an asthma online community, caused distress and frustration in participants, and affected their relationship with health care professionals, showing that patients experiencing BPD and ILO have unmet needs. Clinicians' education on BPD and ILO diagnosis and management, as well as increased access to appropriate management options, such as respiratory physiotherapy and speech and language therapy, are warranted particularly in primary care. Qualitative evidence that engagement with the online community resulted in patients taking action going back to their clinicians and reaching a diagnosis of ILO and BPD prompts future research on online peer support from an established online health community as a self-management resource for patients.

Paradoxical Vocal Fold Dysfunction Mimicking Bronchial Asthma in a Young Female Patient

Inducible laryngeal obstruction (ILO)/paradoxical vocal fold motion (PVFM) is a reversible narrowing of the larynx that results from vocal fold motion dysfunction. Distinguishing ILO from asthma can be challenging, as they can coexist, and standard tests may not be able to differentiate between the two. However, a flexible laryngoscopy can promptly diagnose ILO. Unfortunately, ILO is often overlooked as a potential cause when evaluating patients with sudden-onset breathing difficulties and respiratory distress. We present a case of a young female who sought frequent treatment at the emergency room (ER) with symptoms of shortness of breath (SOB), rapid heart rate, rapid breathing, and anxiety. Despite receiving treatment for acute asthma attacks, her symptoms persisted. During her most recent hospital admission, a flexible laryngoscopy revealed abnormal vocal fold movements, indicating paradoxical vocal fold dysfunction (PVFD) and muscle tension dysphonia (MTD). A comprehensive treatment approach involving speech therapy, pulmonology, and psychiatry led to significant clinical improvement. This case report highlights the importance of raising awareness among healthcare providers about ILO potentially mimicking bronchial asthma exacerbation.

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.

Paroxysmal dyspnoea in asthma: Wheeze, ILO or dysfunctional breathing?

Paroxysms of dyspnoea in the general population are commonly reported and are frequently assumed to be asthma-related, especially if this diagnostic label has been previously applied. Often, this is not the case. Inducible Laryngeal Obstruction (ILO) and Dysfunctional Breathing (DB) are common comorbid conditions that go unrecognised in many difficult-to-treat asthmatics. On average, these patients have a delay in diagnosis of almost 5 years. This delay, along with ineffective, inappropriate escalation of asthma therapy, frequent hospital presentations for uncontrolled symptoms, and even intensive care admissions, magnifies patient morbidity and poor quality of life. ILO and DB have similar presentations and triggers to asthma. Differentiating between them can be challenging, especially in centres that do not have access to multidisciplinary subspecialty asthma services. Objectively confirming the diagnosis can likewise be challenging as symptoms fluctuate, and gold-standard investigations require extensive experience. This mini-review will summarise the clinical features of ILO and DB, with particular focus in the context of individuals treated for asthma. This narrative review will define each condition, highlight poignant aspects of the history and describe elements of the diagnostic pathway to gain objective confirmation.

Long-term pulmonary sequelae in adolescents post-SARS-CoV-2 infection

RATIONALE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes long-term pulmonary sequelae in adults, but little is known about pulmonary outcomes in pediatrics.

OBJECTIVE(S)

The aim of this study was to describe long-term subjective and objective pulmonary abnormalities after SARS-CoV-2 infection in pediatric populations.

METHODS

Single-center, retrospective cohort of patients seen in post-coronavirus disease 2019 (COVID-19) pulmonary clinic in 2021. Subjects evaluated had persistent pulmonary symptoms 4 weeks or more after initial infection. Clinical testing included a 6-min walk test (6MWT), chest X-ray, pre- and postbronchodilator spirometry, plethysmography, and diffusion capacity. Patients were followed 2-to-3-months after the initial visit with repeat testing. The primary outcome was the presence of abnormal pulmonary function testing. Secondary measures included variables associated with pulmonary outcomes.

RESULTS

Eighty-two adolescents were seen at a median of 3.5 months postinfection, with approximately 80% reporting two or more symptoms at clinic presentation (cough, chest pain, dyspnea at rest, and exertional dyspnea). At follow-up (~6.5 months) exertional dyspnea persisted for most (67%). Spirometry was normal in 77% of patients, but 31% had a positive bronchodilator response. No abnormalities were noted on plethysmography or diffusion capacity. Clinical phenotypes identified included inhaled corticosteroid responsiveness, paradoxical vocal fold motion disorder, deconditioning, and dysautonomia. Multivariable modeling demonstrated that obesity, anxiety, and resting dyspnea were associated with reduced 6MWT, while female sex and resting dyspnea were associated with higher Borg Dyspnea and Fatigues scores.

CONCLUSIONS

This is the largest study to date of pediatric patients with long-term pulmonary sequelae post-COVID-19. Identified clinical phenotypes and risk factors warrant further study and treatment.

Factors impacting therapy duration in children and adolescents with Paradoxical Vocal Fold Movement (PVFM)

PURPOSE

Paradoxical Vocal Fold Movement (PVFM) may cause airway restriction and resulting dyspnea in the pediatric population. Therapy with a speech-language pathologist (SLP) is the primary treatment for children and adolescents diagnosed with Paradoxical Vocal Fold Movement (PVFM). This study examined treatment duration and factors predicting number of therapy sessions required.

METHODS

Data were drawn from the University of Wisconsin-Madison Voice and Swallow Clinics Outcome Database. One hundred and twelve children and adolescents were included in this study. Participants were diagnosed with PVFM, followed for therapy with a SLP, and were subsequently discharged from therapy with successful outcomes. Extracted data included number of therapy sessions, PVFM symptoms, patient demographics, medical history, and comorbid diagnoses. Regression was used to determine factors predicting therapy duration.

RESULTS

Patients completed an average of 3.4 therapy sessions before discharge. Comorbid behavioral health diagnosis (β = 1.96, t = 3.83, p < .01) and a history of upper airway surgeries (β = 1.26, t = 2.615, p = .01) were significant predictors of the number of therapy sessions required before discharge; both factors significantly increased therapy duration. Age, symptom trigger-type, reflux symptoms, and dysphonia did not predict therapy duration. Overall, our regression model accounted for 42% of the variance in number of sessions required (r² = 0.42).

CONCLUSIONS

On average, 3.4 sessions of therapy with an SLP resolved PVFM symptoms. Children with a behavioral health diagnosis required an average of 5.45 sessions and those with a history of upper airway surgery an average of 4.3 sessions. Future work should examine the relationship between behavioral health care and PVFM treatment, as well as how PVFM treatment efficiency can be maximized.

Type 2 inflammation in asthma and other airway diseases

Chronic inflammatory airway diseases, including asthma, chronic rhinosinusitis, eosinophilic COPD and allergic rhinitis are a global health concern. Despite the coexistence of these diseases and their common pathophysiology, they are often managed independently, resulting in poor asthma control, continued symptoms and poor quality of life. Understanding disease pathophysiology is important for best treatment practice, reduced disease burden and improved patient outcomes. The pathophysiology of type 2 inflammation is driven by both the innate immune system triggered by pollutants, viral or fungal infections involving type 2 innate lymphoid cells (ILC2) and the adaptive immune system, triggered by contact with an allergen involving type 2 T-helper (Th2) cells. Both ILC2 and Th2 cells produce the type-2 cytokines (interleukin (IL)-4, IL-5 and IL-13), each with several roles in the inflammation cascade. IL-4 and IL-13 cause B-cell class switching and IgE production, release of pro-inflammatory mediators, barrier disruption and tissue remodelling. In addition, IL-13 causes goblet-cell hyperplasia and mucus production. All three interleukins are involved in trafficking eosinophils to tissues, producing clinical symptoms characteristic of chronic inflammatory airway diseases. Asthma is a heterogenous disease; therefore, identification of biomarkers and early targeted treatment is critical for patients inadequately managed by inhaled corticosteroids and long-acting β-agonists alone. The Global Initiative for Asthma guidelines recommend add-on biological (anti IgE, IL-5/5R, IL-4R) treatments for those not responding to standard of care. Targeted therapies, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab and tezepelumab, were developed on current understanding of the pathophysiology of type 2 inflammation. These therapies offer hope for improved management of type 2 inflammatory airway diseases.

The impact of identifying laryngeal obstruction syndromes on reducing treatment of pediatric asthma: A systematic review

Inducible laryngeal obstruction (ILO) in children is underrecognized. This systematic review characterizes the scientific evidence on the impact of pediatric ILO diagnosis and treatment on asthma medication use. This review, registered with PROSPERO (CRD42020209168), utilized database searches in MEDLINE, EMBASE, CINAHL, and Web of Science from inception to October 2020. Both experimental and observational studies on ILO and asthma outcomes in patients ≤18 years were included. Population characteristics (sample size, sex, age, and comorbidities) and study outcomes (medication usage and respiratory symptoms) were extracted. The risk of bias was assessed with the National Toxicology Program's Office of Health Assessment and Risk of Bias Rating Tool. Data are presented narratively due to study heterogeneity. Of 1091 studies, 1076 titles and abstracts were screened after duplicate removal. Screening 31 full texts yielded eight pre-post studies. Patients were an average of 14.1 years old, 15% male, and >90% used asthma medication; 40% reported allergies, 30% gastroesophageal reflux, and 20% anxiety or depression. Most patients received at least one intervention, with 75% showing symptomatic improvement and >75% decreasing or stopping asthma medications. Studies were small with a high risk of selection, confounding, and detection bias. Asthma management was not a primary outcome in any of the studies. Overall, ILO patients were often diagnosed with or treated for asthma before ILO diagnosis. Evidence from individual studies suggests that comorbidities including ILO, gastroesophageal reflux, allergies, and anxiety should be considered in pediatric patients with asthma not responsive to medical therapy. Further research is required to determine the proportion of impacted asthma patients.

2021 Brazilian Thoracic Association recommendations for the management of severe asthma

Advances in the understanding that severe asthma is a complex and heterogeneous disease and in the knowledge of the pathophysiology of asthma, with the identification of different phenotypes and endotypes, have allowed new approaches for the diagnosis and characterization of the disease and have resulted in relevant changes in pharmacological management. In this context, the definition of severe asthma has been established, being differentiated from difficult-to-control asthma. These recommendations address this topic and review advances in phenotyping, use of biomarkers, and new treatments for severe asthma. Emphasis is given to topics regarding personalized management of the patient and selection of biologicals, as well as the importance of evaluating the response to treatment. These recommendations apply to adults and children with severe asthma and are targeted at physicians involved in asthma treatment. A panel of 17 Brazilian pulmonologists was invited to review recent evidence on the diagnosis and management of severe asthma, adapting it to the Brazilian reality. Each of the experts was responsible for reviewing a topic or question relevant to the topic. In a second phase, four experts discussed and structured the texts produced, and, in the last phase, all experts reviewed and approved the present manuscript and its recommendations.

Die induzierbare laryngeale Obstruktion (ILO) – Ursachen, klinische Präsentation, Diagnostik und Therapie

Wiederholt episodenhaft auftretende Atemnot ist im Kindes- und Jugendalter ein häufiges Symptom. Neben anstrengungsinduzierter Bronchialobstruktion im Rahmen eines Asthma bronchiale ist eine funktionelle Genese eine sehr häufige Differenzialdiagnose. Dennoch wird diese Diagnose häufig nicht oder mit langer Latenz gestellt. Unter dem Oberbegriff „ILO“ („inducible laryngeal obstruction“) werden sowohl funktionelle supraglottische Obstruktionen durch Kollaps der Knorpelstrukturen als auch Dysfunktionen auf Glottisebene wie „vocal cord dysfunction“ (VCD) subsumiert. Körperliche Anstrengung ist ein häufiger Auslöser; es werden jedoch auch Beschwerdebilder ohne Anstrengungsbezug beobachtet. Es wird der Erkenntnisstand zur Pathophysiologie referiert und die klinische Präsentation beschrieben. Ein wesentlicher Fokus des Artikels liegt im Folgenden auf der Darstellung eines sinnvollen und Ressourcen-orientierten diagnostischen Vorgehens. Der CLE-Test („continuous laryngoscopy exercise test“) als Provokationsmethode unter Wach-Videolaryngoskopie ist der Goldstandard, jedoch wird diese Diagnostik im deutschsprachigen Raum nicht flächendeckend vorgehalten. Dieses Positionspapier stellt daher die diagnostische Wertigkeit verschiedener anderer Diagnostik-Algorithmen und anamnestischer Informationen heraus. Ein weiterer Schwerpunkt des Papiers besteht in der detaillierten Vorstellung geeigneter atemphysiotherapeutischer Interventionen.

Economic Burden Associated With Management of Paradoxical Vocal Fold Motion Disorder

OBJECTIVES

Paradoxical vocal fold movement (PVFM) is often misdiagnosed as asthma and tends to have a prolonged time to diagnosis. Study aims were to estimate the time from dyspnea onset to PVFM diagnosis, to estimate associated pre- and postdiagnosis direct and indirect healthcare cost, and to compare the cost of postdiagnosis care among patients who did and did not undergo standard-of-care speech therapy.

METHODS

Patients diagnosed with PVFM were identified retrospectively. Time from dyspnea symptom onset to diagnosis was measured. Direct costs consisting of office visits, procedures, and prescribed pharmaceuticals before and after diagnosis were calculated. Indirect costs associated with lost wages related to healthcare were also estimated. Costs for patients who initiated versus did not initiate speech therapy and who had successful versus unsuccessful therapy were compared.

RESULTS

Among 110 patients, median time from dyspnea onset to PVFM diagnosis was 33 months (interquartile range [IQR] 5-60). Direct and indirect prediagnosis median costs were $8,625 (IQR $1,687-$35,812) and $736 (IQR $421-$1,579) while first year following dyspnea symptom onset median direct and indirect costs were $1,706 (IQR $427-$7,118) and $315 (IQR $131-$631). Median direct and indirect costs of care in the postdiagnosis year were $2,062 (IQR $760-$11,496) and $841 (IQR $631-$1,261). Pharmaceuticals were predominant cost drivers in all time periods. Of those who completed speech therapy, 85% had breathing symptom improvement while incurring significant cost savings compared to those whose symptoms persisted.

CONCLUSION

Costs of care leading to diagnosis of PVFM are substantial. More efficient methods of identifying patients with PVFM are essential to reduce prolonged time to diagnosis and associated costs.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Vocal cord dysfunction detected by a three-dimensional image of dynamic change in respiratory resistance in a patient with difficult-to-treat asthma: a case report

INTRODUCTION

Vocal cord dysfunction (VCD) often coexists with asthma and exacerbates respiratory symptoms. A noninvasive method could be considered beneficial for the detection and follow-up of VCD complicated by asthma. Here, we report a case of VCD complicated by asthma, highlighting the effectiveness of colored three-dimensional (3-D) imaging of respiratory impedance using a broadband frequency forced oscillation technique (MostGraph).

CASE STUDY

A 74-year-old woman with difficult-to-treat asthma, in whom mepolizumab treatment was ineffective, was referred to our hospital. Stridulous sounds were loudest over the anterior neck. Pulmonary function tests' results were normal; however, a flattening of the inspiratory flow-volume curve was detected.

RESULTS

Remarkably, prominent spikes were observed in the inspiratory phase in the colored 3-D imaging of respiratory resistance, which was superimposed on increased respiratory resistance in the expiratory phase. Flexible laryngoscopy revealed the adduction of vocal cords on inspiration. The patient was diagnosed with asthma complicated by VCD. After successful treatment of VCD by speech therapy, inspiratory spikes of respiratory resistance disappeared, and normal vocal cord movement was observed on laryngoscopy.

CONCLUSION

The present case report indicates the effectiveness of forced oscillometry in evaluating dynamic changes in respiratory resistance for detecting and monitoring VCD complicated by asthma.

Can the Expiratory Disproportion Index Distinguish PVFMD from Subglottic Stenosis in Obese Patients?

OBJECTIVES

Expiratory disproportion index (EDI) is the ratio of forced expiratory volume in 1 second (FEV1) divided by peak expiratory flow rate (PEFR) multiplied by 100. Prominent EDI (>50) values can differentiate subglottic stenosis (SGS) from paradoxical vocal fold movement disorder (PVFMD), but this has not been verified when considering body habitus. We hypothesize that the predictive value of elevated EDI in differentiating SGS from PVFMD will be lower in obese patients than non-obese patients.

METHODS

Patients ≥ 18 years old with recorded PFT values, BMI, and airway imaging were reviewed retrospectively from 01/2011 to 10/2018. EDI was recorded for 4 cohorts: non-obese/SGS, non-obese/ PVFMD, obese/SGS, and obese/ PVFMD, to determine the mean EDI and the sensitivity/specificity of an elevated EDI.

RESULTS

Mean EDI values were 69.32 and 48.38 in the non-obese SGS and PVFMD groups, respectively (P < .01). They were 58.89 and 47.67 in the obese SGS and PVFMD groups, respectively (P < .05). At a threshold of >50, EDI had a sensitivity of 90.0% and specificity of 51.6% in differentiating between SGS and PVFMD cases in non-obese patients and 51.6% and 63.6% in obese patients.

CONCLUSION

Prior literature has established that EDI can distinguish SGS from PVFMD in the general population. Our results show that the mean EDI values were significantly different in both cohorts, but an elevated EDI was not as sensitive at identifying SGS cases in obese patients. This suggests that the EDI should be used with caution in obese patients and should not be relied upon to rule out SGS.

LEVEL OF EVIDENCE

3.

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.

Impact of comorbid conditions on asthmatic adults and children

Comorbid conditions (comorbidities) can complicate the diagnosis and management of asthma. In different age groups, comorbid conditions can present varying challenges, including diagnostic confusion due to mimicking asthma symptoms, exacerbation of asthma symptoms, therapy for comorbid conditions affecting asthma or therapy for asthma affecting these conditions. This review aims to summarise some common comorbid conditions with asthma, such as rhinitis, vocal cord dysfunction, gastro-oesophageal reflux, psychiatric disorders, obesity and obstructive sleep apnoea, and discuss their prevalence, symptoms, diagnosis and treatment, highlighting any differences in how they impact children and adults. Overall, there is a lack of data on the impact of treating comorbid conditions on asthma outcomes and further studies are needed to guide age-appropriate asthma management in the presence of these conditions.

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.

Managing comorbid conditions in severe asthma

Asthma care has increasingly focused on personalised management for severe asthma, and recognition of the role and importance of comorbid conditions has increased. Severe asthma can be crippling; associated comorbid conditions often play a key role in the significant disease morbidity and frequently contribute to a severe and difficult-to-treat asthma phenotype. Comorbid conditions can be broadly grouped as being either airway-related or airway-unrelated. Airway-related comorbid conditions with the greatest impact are allergic rhinitis, chronic rhinosinusitis, vocal cord dysfunction, lung fungal sensitisation and underlying structural lung disease. The most important airway-unrelated comorbid conditions are obesity, obstructive sleep apnoea, gastro-oesophageal reflux disease and anxiety and depression. A diagnostic and management algorithm for comorbid conditions in severe asthma is outlined. It concentrates initially on the group with common comorbid conditions that can be managed in primary care. If asthma remains troublesome, emphasis can shift to identifying uncommon and more complex factors. The algorithm allows for personalised diagnostic and management pathways to be implemented. Personalised diagnosis and management of comorbid conditions are essential to achieving effective and improved outcomes for patients with severe asthma.

Dysfunctional Breathing in Children and Adults With Asthma

Asthma occurs across the life course. Its optimal treatment includes the use of personalized management plans that recognize the importance of co-morbidities including so-called "dysfunctional breathing." Such symptoms can arise as a result of induced laryngeal obstruction (ILO) or alterations in the mechanics of normal breathing called breathing pattern disorders. Whilst these two types of breathing abnormalities might be related, studies tend to focus on only one of them and do not consider their relationship. Evidence for these problems amongst childhood asthmatics is largely anecdotal. They seem rare in early childhood. Both types are more frequently recognized in the second decade of life and girls are affected more often. These observations tantalizingly parallel epidemiological studies characterizing the increasing prevalence and severity of asthma that also occurs amongst females after puberty. Exercise ILO is more common amongst adolescents and young adults. It should be properly delineated as it might be causally related to specific treatable factors. More severe ILO occurring at rest and breathing pattern disorders are more likely to be occurring within a psychological paradigm. Dysfunctional breathing is associated with asthma morbidity through a number of potential mechanisms. These include anxiety induced breathing pattern disorders and the enhanced perception of subsequent symptoms, cooling and drying of the airways from hyperventilation induced hyperresponsiveness and a direct effect of emotional stimuli on airways constriction via cholinergic pathways. Hyperventilation is the most common breathing pattern disorder amongst adults. Although not validated for use in asthma, the Nijmegen questionnaire has been used to characterize this problem. Studies show higher scores amongst women, those with poorly controlled asthma and those with psychiatric problems. Evidence that treatment with breathing retraining techniques is effective in a primary care population including all types of asthmatics suggests the problem might be more ubiquitous than just these high-risk groups. Future challenges include the need for studies characterizing all types of dysfunctional breathing in pediatric and adult patient cohorts and clearly defined, age appropriate, interventional studies. Clinicians caring for asthmatics in all age groups need to be aware of these co-morbidities and routinely ask about symptoms that suggest these problems.

Nonallergic Triggers and Comorbidities in Asthma Exacerbations and Disease Severity

Asthma triggers are exogenous or endogenous factors that could worsen asthma acutely to cause an exacerbation, or perpetuate chronic symptoms and airflow limitation. Because it is well known that recent asthma exacerbations and poor symptom control are strong predictors of future disease activity, it is not surprising that the number of (allergic or nonallergic) asthma triggers in the environment correlates with the disease-related quality of life. There is a need to identify and avoid specific triggers as the centerpiece of disease management, especially in those with heightened sensitivity to certain factors.

Current opinions for the management of asthma associated with ear, nose and throat comorbidities

Ear, nose and throat (ENT) comorbidities are common in patients with asthma and are frequently associated with poorer asthma outcomes. All these comorbidities are "treatable traits" in asthma. Identification and management of these disorders may spare medication usage and contribute to improved asthma control and quality of life, and a decrease in exacerbation rates.This review summarises recent data about the prevalence, clinical impact and treatment effects of ENT comorbidities in asthma including allergic rhinitis, chronic rhinosinusitis with and without nasal polyposis, aspirin-exacerbated respiratory disease, obstructive sleep apnoea and vocal cord dysfunction.Many of these comorbidities are possible to be managed by the pulmonologist, but the collaboration with the ENT specialist is essential for patients with chronic rhinosinusitis or vocal cord dysfunction. Further rigorous research is needed to study the efficacy of comorbidity treatment to improve asthma outcomes, in particular with the development of biotherapies in severe asthma that can also be beneficial in some ENT diseases.

Co-existence of vocal cord dysfunction with pulmonary conditions other than asthma: A case series

Background

Vocal cord dysfunction (VCD) is defined as inappropriate movement of the vocal cords resulting in functional airway obstruction and symptoms including cough, wheezing, and dyspnea. VCD is often misdiagnosed with asthma but can also co-exist with asthma. The association of VCD with other serious pulmonary conditions has not been described to date.

Case reports

We describe the first case series of two adult patients evaluated at a university asthma clinic who in addition to having VCD also had significant pulmonary pathology other than asthma. Patient 1 had VCD and pulmonary veno-occulsive disease which necessitated a lung transplant. Patient 2 had VCD and a patent ductus arteriosis who necessitated surgical closure.

Conclusion

It is important to recognize that VCD can exist with pulmonary conditions other than asthma. Lack of improvement in respiratory symptoms after appropriate treatment for VCD should alert the clinician to evaluate for additional conditions.

Comorbid "treatable traits" in difficult asthma: Current evidence and clinical evaluation

The care of patients with difficult-to-control asthma ("difficult asthma") is challenging and costly. Despite high-intensity asthma treatment, these patients experience poor asthma control and face the greatest risk of asthma morbidity and mortality. Poor asthma control is often driven by severe asthma biology, which has appropriately been the focus of intense research and phenotype-driven therapies. However, it is increasingly apparent that extra-pulmonary comorbidities also contribute substantially to poor asthma control and a heightened disease burden. These comorbidities have been proposed as "treatable traits" in chronic airways disease, adding impetus to their evaluation and management in difficult asthma. In this review, eight major asthma-related comorbidities are discussed: rhinitis, chronic rhinosinusitis, gastroesophageal reflux, obstructive sleep apnoea, vocal cord dysfunction, obesity, dysfunctional breathing and anxiety/depression. We describe the prevalence, impact and treatment effects of these comorbidities in the difficult asthma population, emphasizing gaps in the current literature. We examine the associations between individual comorbidities and highlight the potential for comorbidity clusters to exert combined effects on asthma outcomes. We conclude by outlining a pragmatic clinical approach to assess comorbidities in difficult asthma.

Differentiating vocal cord dysfunction from asthma

Vocal cord dysfunction (VCD)-associated symptoms are not rare in pediatric patients. Dyspnea, wheezing, stridor, chest pain or tightness and throat discomfort are the most commonly encountered symptoms. They may occur either at rest or more commonly during exercise in patients with VCD, as well as in asthmatic subjects. The phase of respiration (inspiration rather than expiration), the location of the wheezing origin, the rapid resolution of symptoms, and the timing occurring in relation to exercise, when VCD is exercise induced, raise the suspicion of VCD in patients who may have been characterized as merely asthmatics and, most importantly, had not responded to the appropriate treatment. The gold standard method for the diagnosis of VCD is fiberoptic laryngoscopy, which may also identify concomitant laryngeal abnormalities other than VCD. However, as VCD is an intermittent phenomenon, the procedure should be performed while the patient is symptomatic. For this reason, challenges that induce VCD symptoms should be performed, such as exercise tests. Recently, for the evaluation of patients with exercise-induced VCD, continuous laryngoscopy during exercise (such as treadmill, bicycle ergometer, swimming) was used. A definite diagnosis of VCD is of importance, especially for those patients who have been erroneously characterized as asthmatics, without adequate response to treatment. In these cases, another therapeutic approach is necessary, which will depend on whether they suffer solely from VCD or from both conditions.

Exercise inducible laryngeal obstruction: diagnostics and management

Obstruction of the central airways is an important cause of exercise-induced inspiratory symptoms (EIIS) in young and otherwise healthy individuals. This is a large, heterogeneous and vastly understudied group of patients. The symptoms are too often confused with those of asthma. Laryngoscopy performed as symptoms evolve during increasing exercise is pivotal, since the larynx plays an important role in symptomatology for the majority. Abnormalities vary between patients, and laryngoscopic findings are important for correct treatment and handling. The simplistic view that all EIIS is due to vocal cord dysfunction [VCD] still hampers science and patient management. Causal mechanisms are poorly understood. Most treatment options are based on weak evidence, but most patients seem to benefit from individualised information and guidance. The place of surgery has not been settled, but supraglottoplasty may cure well-defined severe cases. A systematic clinical approach, more and better research and randomised controlled treatment trials are of utmost importance in this field of respiratory medicine.

Does treatment of paradoxical vocal fold movement disorder decrease asthma medication use?

OBJECTIVES/HYPOTHESIS

To determine whether diagnosis and treatment of paradoxical vocal fold movement disorder (PVFMD) leads to decreased asthma medication use. Secondary objectives include determining initial rate of asthma medication use, characterizing symptom improvement, and correlating with pulmonary function testing (PFT).

STUDY DESIGN

Prospective observational study.

METHODS

Patients newly diagnosed with PVFMD at a single institution were recruited to participate. Medication questionnaires were completed at the initial visit, at the first return visit for therapy, and at 6 months. PFTs were reviewed when available.

RESULTS

Sixty-six patients were recruited; the study was closed early because findings reached significance. Fifty-six patients (85%) were taking asthma medication at presentation. Forty-four patients presented with PFTs, and two-thirds were normal. Forty-two patients completed follow-up questionnaires; 79% decreased asthma medication use (P < .001), and 82% reported symptom improvement. Seventy-seven percent of patients participated in therapy and 23% did not, with equal rates of decrease in asthma medication use between these groups. Outcomes did not vary based on PFT pattern (i.e., obstructive vs. nonobstructive, P = .75).

CONCLUSIONS

Diagnosis and treatment of PVFMD lead to a decline in asthma medication use. This decrease occurred alongside symptom improvement and irrespective of PFT findings. Use of asthma medication in this patient population is high, at 85%.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1531-1537, 2017.

Upper Respiratory Tract Diseases in Athletes in Different Sports Disciplines

Upper respiratory tract diseases in athletes are a very common medical problem. Training conditions in different sports disciplines increase the risk of upper respiratory disease. Epidemiological evidence suggests that heavy acute or chronic exercise is related to an increased incidence of upper respiratory tract infections in athletes. Regular physical exercise at high intensity may lead to transient immunosuppression due to high prevalence of allergic diseases in athletes. Regardless of the cause they can exclude athletes from the training program and significantly impair their performance. In the present work, the most common upper respiratory tract diseases in athletes taking into account the disciplines in which they most often occur were presented. The focus was laid on symptoms, diagnostic methods and pharmacotherapy. Moreover, preventive procedures which can help reduce the occurrence of upper respiratory tract disease in athletes were presented. Management according to anti-doping rules, criteria for return to training and competition as an important issues of athlete’s health were discussed.

Validated questionnaires heighten detection of difficult asthma comorbidities

OBJECTIVE

Multiple extra-pulmonary comorbidities contribute to difficult asthma, but their diagnosis can be challenging and time consuming. Previous data on comorbidity detection have focused on clinical assessment, which may miss certain conditions. We aimed to locate relevant validated screening questionnaires to identify extra-pulmonary comorbidities that contribute to difficult asthma, and evaluate their performance during a difficult asthma evaluation.

METHODS

MEDLINE was searched to identify key extra-pulmonary comorbidities that contribute to difficult asthma. Screening questionnaires were chosen based on ease of use, presence of a cut-off score, and adequate validation to help systematically identify comorbidities. In a consecutive series of 86 patients referred for systematic evaluation of difficult asthma, questionnaires were administered prior to clinical consultation.

RESULTS

Six difficult asthma comorbidities and corresponding screening questionnaires were found: sinonasal disease (allergic rhinitis and chronic rhinosinusitis), vocal cord dysfunction, dysfunctional breathing, obstructive sleep apnea, anxiety and depression, and gastro-oesophageal reflux disease. When the questionnaires were added to the referring clinician's impression, the detection of all six comorbidities was significantly enhanced. The average time for questionnaire administration was approximately 40 minutes.

CONCLUSIONS

The use of validated screening questionnaires heightens detection of comorbidities in difficult asthma. The availability of data from a battery of questionnaires prior to consultation can save time and allow clinicians to systematically assess difficult asthma patients and to focus on areas of particular concern. Such an approach would ensure that all contributing comorbidities have been addressed before significant treatment escalation is considered.

Inhaled Mannitol as a Laryngeal and Bronchial Provocation Test

OBJECTIVES

Timely diagnosis of vocal cord dysfunction (VCD), more recently termed "inducible laryngeal obstruction," is important because VCD is often misdiagnosed as asthma, resulting in delayed diagnosis and inappropriate treatment. Visualization of paradoxical vocal cord movement on laryngoscopy is the gold standard for diagnosis, but is limited by poor test sensitivity. Provocation tests may improve the diagnosis of VCD, but the diagnostic performance of current tests is less than ideal. Alternative provocation tests are required. This pilot study demonstrates the feasibility of using inhaled mannitol for concurrent investigation of laryngeal and bronchial hyperresponsiveness.

METHODS

Consecutive patients with suspected VCD seen at our institution's asthma clinic underwent flexible laryngoscopy at baseline and following mannitol challenge. VCD was diagnosed on laryngoscopy based on inspiratory adduction, or >50% expiratory adduction of the vocal cords. Bronchial hyperresponsiveness after mannitol challenge was also assessed. We evaluated the interrater agreement of postmannitol laryngoscopy between respiratory specialists and laryngologists.

RESULTS

Fourteen patients with suspected VCD in the context of asthma evaluation were included in the study. Mannitol provocation demonstrated VCD in three of the seven patients with normal baseline laryngoscopy (42.9%). Only two patients had bronchial hyperresponsiveness. There was substantial interrater agreement between respiratory specialists and laryngologists, kappa = 0.696 (95% confidence interval: 0.324-1) (P = 0.006).

CONCLUSION

Inhaled mannitol can be used to induce VCD. It is well tolerated and can evaluate laryngeal and bronchial hyperresponsiveness at the same setting.

The VCDQ--a Questionnaire for symptom monitoring in vocal cord dysfunction

BACKGROUND

Vocal cord dysfunction (VCD) typically involves abnormal adduction of the vocal cords during inspiration, mimics the symptoms of asthma and leads to the prescription of ineffective medications.

OBJECTIVE

We aimed to develop a clinical tool to monitor symptoms and response to treatment in confirmed VCD.

METHODS

We collated symptoms of VCD from focus groups comprising patients and healthcare professionals; phrases describing these symptoms were assessed for face validity and internal correlation and rated for importance. The resultant 12-item questionnaire (VCDQ) rated the impact of each on a 5-point Likert scale (total score range 12-60) and was tested for reliability, concurrent validity and performance in 31 patients with endoscopically confirmed VCD (± asthma), 29 asthmatics with no history of VCD and 14 healthy controls. We assessed response to speech and language therapy and the minimal important difference by measuring the VCDQ pre- and post- therapy in a 20 new patients.

RESULTS

The VCDQ had excellent test-retest reliability and differentiated VCD vs. healthy (Mann-Whitney U-test: z = -5.390, P < 0.001) and asthma (z = -5.730, P < 0.001). All patients improved post-therapy, assessed both by a global rating of change score (GRCS) and by the VCDQ [median (IQR) score pre-therapy 50.5 (48.0 - 54.8), post-therapy 35.0 (29.3 - 41.8), P < 0.001]. The minimal important difference in the VCDQ associated with a rating of 'minimally better' on the GRCS was 4 points.

CONCLUSIONS AND CLINICAL RELEVANCE

The VCDQ is a valid and responsive tool suitable for measuring changes in symptoms in patients with VCD. It also gives insight into which symptoms are important to patients and could guide future therapy refinements. Future assessments of novel therapies for this condition should use an appropriately validated tool such as the VCDQ to measure response.

Vocal cord dysfunction diagnosis may be improved by a screening check list

BACKGROUND

Many patients with vocal cord dysfunction (VCD), with or without asthma, receive inappropriate treatment because they are misdiagnosed as having difficult-to-control asthma alone. We developed a clinical screening check list designed to aid the diagnosis of VCD.

METHODS

A prospective observational study involving 80 patients aged ≥18 years, diagnosed with severe asthma. After anamnesis and physical examination, physicians completed a check list with 6 questions to identify VCD, for which the answer "yes" counted one point. Then patients underwent spirometry and laryngoscopy. On the basis of the laryngoscopic findings, we created three patient groups: VCD (vocal cord adduction during inspiration, n = 14); unconfirmed VCD (inconclusive findings, n = 29); and control (normal findings, n = 37). We attempted to determine whether any of those groups were associated with the responses to individual questions or sets of questions on the check list.

RESULTS

The proportion of affirmative answers to the question "Does pulmonary auscultation reveal wheezing, predominantly in the cervical region, and/or stridor?" was significantly higher for the VCD group than for the other two groups (P = 0.006), notably in elderly patients. The variable "4 or more affirmative answers" was more common in VCD and unconfirmed VCD groups in comparison to controls (P = 0.022).

CONCLUSIONS

A finding of wheezing or stridor on auscultation of the cervical region is suggestive of vocal cord dysfunction, especially in elderly patients, and such dysfunction can be confirmed through laryngoscopy. Our VCD screening check list proved to be useful in the screening of VCD among patients with severe asthma.

Larynx during exercise: the unexplored bottleneck of the airways

Exercise-induced shortness of breath is not uncommon in otherwise healthy young people. Based on the presenting symptoms alone, it is challenging to distinguish exercise-induced asthma (EIA) from exercise-induced obstruction of central airways, sometimes leading to diagnostic errors and inadequate treatment. Central airway obstruction usually presents with exercise-induced inspiratory symptoms (EIIS) during ongoing exercise. EIIS tends to peak towards the end of an exercise session or immediately after its completion, contradicting symptoms of EIA typically peaking 3-15 min after the exercise has stopped. EIIS is usually associated with some form of laryngeal obstruction. Transnasal flexible laryngoscopy performed continuously throughout an incremental exercise test from rest to exhaustion or to intolerable symptoms is usually diagnostic, and also provides information that is important for further handling and treatment. Reflecting the complex anatomy and functional features of the larynx, exercise-induced laryngeal obstruction (EILO) appears to be a heterogeneous condition. Contradicting previous beliefs, recent literature suggests that laryngeal adduction in a majority of cases starts in supraglottic structures and that vocal cord adduction (VCD) most often occurs as a secondary phenomenon. However, EILO is poorly understood and more and better research is needed to unravel causal mechanisms. The evidence base for treatment of EILO is weak. Speech therapy, psychotherapy, biofeedback, muscle training, anticholinergic aerosols have all been applied, as has laser supraglottoplasty. Randomized controlled trials with well-defined and verifiable inclusion and success criteria are required to establish evidence-based treatment schemes.

Bronchial thermoplasty in asthma: current perspectives

Bronchial thermoplasty (BT) is a novel therapy for patients with severe asthma. Using radio frequency thermal energy, it aims to reduce the airway smooth muscle mass. Several clinical trials have demonstrated improvements in asthma-related quality of life and a reduction in the number of exacerbations following treatment with BT. In addition, recent data has demonstrated the long-term safety of the procedure as well as sustained improvements in rates of asthma exacerbations, reduction in health care utilization, and improved quality of life. Further study is needed to elucidate the underlying mechanisms that result in these improvements. In addition, improved characterization of the asthma subphenotypes likely to exhibit the largest clinical benefit is a critical step in determining the precise role of BT in the management of severe asthma.

Asthma in pregnancy: Physiology, diagnosis, and management

Asthma is a common, potentially serious, medical condition that affects an estimated 8% of pregnant patients, with 4% of all pregnant patients experiencing an exacerbation in the past year. Practitioners must be able to diagnose, educate, and treat such patients as they undergo significant physiological and immunologic change. But staying current can be challenging given over 3000 citations for "asthma and pregnancy" in a recent PubMed search, with 750 described as review articles. Patients have even more difficulty navigating information, with 29 million Google search results for this same query and 1.2 million alone for the question whether asthma medications are safe during pregnancy. This review provides brief answers to important management questions followed by supporting background literature.

Exercise-induced bronchoconstriction and vocal cord dysfunction: two sides of the same coin?

Patients are referred often because of self-reported symptoms of dyspnea and wheeze during exercise. The two common causes of exercise-induced dyspnea are exercise-induced bronchoconstriction (EIB) and vocal cord dysfunction (VCD). It can be extraordinarily difficult to differentiate between the two, especially because they may coexist in the same patient. EIB is caused by bronchial smooth muscle constriction in the lower airways due to the inhalation of dry air or allergens during exercise; it is associated with the release of bronchoconstricting mediators from airway cells. EIB can occur in patients with or without persistent asthma. In contrast, VCD is associated with the paradoxical adduction of the vocal cords, especially during inhalation, which may produce inspiratory stridor. VCD can be solitary or comorbid with asthma and/or EIB. EIB classically is most severe after the cessation of exercise, while VCD typically occurs during exercise and resolves quickly upon exercise cessation. However, history is not adequate to differentiate between EIB and VCD, and appropriate challenge tests and flexible laryngoscopy during exercise are often necessary for diagnosis. This article examines our current understanding of these entities and discusses the mechanism, prevalence, diagnosis, and treatment.

Difficult-to-treat asthma in childhood

Asthma continues to be one of the greatest burdens to healthcare resources throughout the developed world. In most cases, good symptom control can be achieved with low-dose inhaled corticosteroids, and can be cared for in the primary and secondary healthcare systems. However, there is a group in whom control is not achieved despite high-dose inhaled corticosteroids and maximal add-on therapies; these are children with problematic severe asthma that should be referred to a specialist team for further investigation and management. In this review we aimed to provide an evidence-based guide for pediatricians providing care for children with asthma in secondary healthcare settings. The review focuses on a proposed investigation and management strategy for children aged between 6 and 16 years with problematic severe asthma, and is supported as far as possible by evidence from the literature. We first address recent advances in nomenclature and then discuss our proposed course of investigation and management of these children. Distinction of children with true, severe, therapy-resistant asthma from those with asthma that is difficult to treat because of unaddressed underlying modifiable factors is critical and is discussed in detail.

Work-related laryngeal syndromes

PURPOSE OF REVIEW

This review summarizes recent literature regarding the association of nonorganic laryngeal dysfunction with occupational exposures. Laryngeal dysfunction may masquerade as asthma and is an important consideration in patients with work-associated respiratory symptoms.

RECENT FINDINGS

Although there is lack of consensus regarding clinical features, vocal cord dysfunction (VCD) is the most well appreciated form of nonorganic laryngeal dysfunction. There are significant gaps in the literature regarding the occupational epidemiology of laryngeal dysfunction, however, occupational exposures such as upper airway irritants may be associated with the onset of symptoms. Recurrent work-associated laryngeal dysfunction has been described in occupational groups including the military and professional athletes. Recent theories have considered that VCD may be a state of laryngeal hyperresponsiveness associated with both intrinsic and extrinsic factors.

SUMMARY

Laryngeal dysfunction is an important consideration in patients with work-associated respiratory symptoms. Clinicians should have a high index of suspicion, in particular, if symptoms are associated with exposure to a respiratory irritant. Situations of high psychological stress may also be associated with recurrent symptoms. There is a requirement for evidence-based guidelines for the diagnosis and management of laryngeal dysfunction, which should also address work-related factors.

Vocal cord dysfunction and asthma

PURPOSE OF REVIEW

Vocal cord dysfunction can occur independently or can co-exist with asthma. It often mimics asthma in presentation and can be challenging to diagnose, particularly in those with known asthma. Vocal cord dysfunction remains under-recognized, which may result in unnecessary adjustments to asthma medicines and increased patient morbidity. There is a need to review current literature to explore current theories regarding disease presentation, diagnosis, and treatment.

RECENT FINDINGS

The underlying cause of vocal cord dysfunction is likely multifactorial but there has been increased interest in hyper-responsiveness of the larynx. Many intrinsic and extrinsic triggers have been identified which in part may explain asthma-like symptomatology. A variety of techniques have been reported to provoke vocal cord dysfunction during testing which may improve diagnosis. There is a significant gap in the literature regarding specific laryngeal control techniques, duration of therapy, and the effectiveness of laryngeal control as a treatment modality.

SUMMARY

Those with vocal cord dysfunction and asthma report more symptoms on standardized asthma control questionnaires, which can result in increasing amounts of medication if vocal cord dysfunction is not identified and managed appropriately. Clinicians need to maintain a high index of suspicion to identify these patients. Videolaryngostroboscopy remains the diagnostic method of choice. Evidence-based guidelines are needed for the most effective diagnostic techniques. Laryngeal control taught by speech pathologists is the most common treatment. Effectiveness is supported in case reports and clinical experience, but not in larger randomized trials which are needed.