Common causes and current guidelines

The Diagnosis and Time of Onset of Voice Disorders in Patients with Chronic Cough

OBJECTIVES

Chronic cough is a complaint of up to 46% of patients referred to specialist clinics. Patients with cough often report hoarseness at the time of the cough diagnosis. When the cough fails to resolve with standard medications, referrals to other specialists including otolaryngologists are made. This is the first study to report the specific diagnosis and length of time it took to obtain a specific voice disorder diagnosis in patients with chronic cough.

STUDY DESIGN

Case Series METHODS: The charts of 105 patients referred to the Loma Linda Voice and Swallowing Center were reviewed. The first complaint of cough and/or hoarseness and the specific voice disorder diagnosis following otolaryngologic evaluation were identified. Voice disorders were divided into neurogenic or other/functional disorders and common comorbidities were identified. Statistical analysis between diagnostic groups, gender, and age were obtained.

RESULTS

The specific voice disorders in the cohort were identified. There was a high prevalence of neurogenic voice disorders (n = 85, 81%). There were significant relationships between chronic cough and the two most common neurogenic voice disorders, vocal fold paresis and vocal fold atrophy. The average length of time between complaint of hoarseness and the specific voice disorder diagnosis was 32.3 months. Most patients (86%) complained of voice problems after diagnosis of chronic cough. A significant association was found in prevalence of asthma (OR = 4.52, P = 0.02) and dyspnea (OR = 4.24, P = 0.02) in the cohort who presented first with voice complaints and later developed chronic cough.

CONCLUSIONS

There is a high incidence of neurogenic voice disorders accompanying patients with chronic cough. Understanding the relationship between chronic cough and hoarseness provides the clinician with specific diagnostic information in the treatment of both disorders.

Health-related experiences of adults with chronic cough: Empirical research mixed methods

AIM

To describe adults' health-related experiences with chronic cough.

DESIGN

Survey and interviews.

METHODS

Participants completed questionnaires and interviews, to explore chronic cough's impact and management.

DATA SOURCES

Patients aged 18-85 years with at least three cough-related encounters within 56-120 days.

RESULTS

Forty-one patients were surveyed. Mean cough severity was 4.5 (scale 0-9). Chronic cough-related problems included embarrassment (66%), fatigue (56%), and anxiety or depression (49%). Testing was judged insufficient by 44%. Only 28% were satisfied with treatment; 20% reported abandoning treatment due to ineffectiveness. Interview themes (N = 30) included frustration with diagnostic uncertainty, and feelings of therapeutic futility. Some reported psychological distress. Work and socializing were commonly disrupted.

CONCLUSION

Diagnostic uncertainty, perceived limitations of testing, and treatment failures suggest needs for better approaches to evaluating and treating chronic cough. Special attention to identifying and addressing mental health issues appears warranted.

Integrate UPLC-QE-MS/MS and Network Pharmacology to Investigate the Active Components and Action Mechanisms of Tea Cake Extract for Treating Cough

OBJECTIVE

Investigate the active components and mechanisms of tea cake extract (TCE) for treating cough.

METHODS

The components of TCE were tentatively identified by ultrahigh performance liquid chromatography coupled with Q-Exactive MS/MS (UPLC-QE-MS/MS), whose targets were obtained from databases of Swiss Target Prediction and traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP). Cough-related targets were retrieved from databases of Gene cards and Online Mendelian Inheritance in Man (OMIM). After intersection targets were obtained, enrichment analysis of Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was performed, and protein-protein interactions (PPI) network and active compound-intersection target-KEGG pathway network was constructed. Core active compounds and their targets were validated with molecular docking.

RESULTS

Total of 78 compounds were identified from TCE, including 24 flavonoids, 17 phenolic acids, 10 alkaloids, 7 organic acids, 5 triterpenes, 5 amino acids, 5 coumarins, 3 carbohydrates, 1 anthraquinone and 1 other. 347 intersection targets were obtained. The top 5 GO terms with most significant P-values were response to oxygen-containing compound, response to organic substance, response to chemical, cellular response to chemical stimulus, and regulation of biological quality. The top 5 KEGG pathways with most significant P-values were: PI3K-Akt signaling pathway, lipid and atherosclerosis, human cytomegalovirus infection, fluid shear stress and atherosclerosis, and proteoglycans in cancer. The top 5 core active compounds were: quercetin, genistein, luteolin, kaempferol and emodin. The top 5 core targets were: protein kinase B (Akt1), prostaglandin-endoperoxide synthase 2 (PTGS2), mitogen-activated protein kinase 1/3 (MAPK1/3), and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1). The top 5 core active compounds could stably bind to their targets with LibDockScore higher than 100.

CONCLUSION

TCE plays the antitussive role by multiple components and targets. Core targets (AKT1, MAPK1, MAPK3 and PIK3R1) and core components (quercetin, genistein, luteolin and kaempferol) involved in the PI3K-Akt signaling pathway are worth more attention in subsequent validation experiments.

Clinical Effects and Safety of Zhi Sou San for Cough: A Meta-Analysis of Randomized Trials

Introduction

Zhi Sou San (ZSS), a traditional Chinese prescription, has been widely applied in treating cough. The purpose of this meta-analysis was to evaluate the effectiveness and safety of ZSS for cough.

Methods

We searched relevant articles up to 5 March 2017 in seven electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed, Chinese National Knowledge Infrastructure (CNKI), Cqvip Database (VIP), China Biology Medicine disc (CBM), and Wanfang Data. Randomized controlled trials (RCTs) were eligible, regardless of blinding. The primary outcome was the total effective rate.

Results

Forty-six RCTs with a total of 4007 participants were identified. Compared with western medicine, ZSS significantly improved the total effective rate (OR: 4.45; 95% CI: 3.62–5.47) and the pulmonary function in terms of FEV1 (OR: 0.35; 95% CI: 0.24–0.46) and decreased the adverse reactions (OR: 0.05; 95% CI: 0.02–0.01) and the recurrence rate (OR: 0.30; 95% CI: 0.16–0.57). However, there was no significant improvement in the cough symptom score comparing ZSS with western medicine.

Conclusions

This meta-analysis shows that ZSS has significant additional benefits and relative safety in treating cough. However, more rigorously designed investigations and studies, with large sample sizes, are needed because of the methodological flaws and low quality of the included trials in this meta-analysis.

Targeting TRP channels for chronic cough: from bench to bedside

Cough is currently the most common reason for patients to visit a primary care physician in the UK, yet it remains an unmet medical need. Current therapies have limited efficacy or have potentially dangerous side effects. Under normal circumstances, cough is a protective reflex to clear the lungs of harmful particles; however, in disease, cough can become excessive, dramatically impacting patients' lives. In many cases, this condition is linked to inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD), but can also be refractory to treatment and idiopathic in nature. Therefore, there is an urgent need to develop therapies, and targeting the sensory afferent arm of the reflex which initiates the cough reflex may uncover novel therapeutic targets. The cough reflex is initiated following activation of ion channels present on vagal sensory afferents. These ion channels include the transient receptor potential (TRP) family of cation-selective ion channels which act as cellular sensors and respond to changes in the external environment. Many direct activators of TRP channels, including arachidonic acid derivatives, a lowered airway pH, changes in temperature, and altered airway osmolarity are present in the diseased airway where responses to challenge agents which activate airway sensory nerve activity are known to be enhanced. Furthermore, the expression of some TRP channels is increased in airway disease. Together, this makes them promising targets for the treatment of chronic cough. This review will cover the current understanding of the role of the TRP family of ion channels in the activation of airway sensory nerves and cough, focusing on four members, transient receptor potential vanilloid (TRPV) 1, transient receptor potential ankyrin (TRPA) 1, TRPV4, and transient receptor potential melastatin (TRPM) 8 as these represent the channels where most information has been gathered with relevance to the airways. We will describe recent data and highlight the possible therapeutic utility of specific TRP channel antagonists as antitussives in the clinic.

Management and diagnosis of psychogenic cough, habit cough, and tic cough: a systematic review

BACKGROUND

Several pharmacologic and nonpharmacologic therapeutic options have been used to treat cough that is not associated with a pulmonary or extrapulmonary etiology.

METHODS

We conducted a systematic review to summarize the evidence supporting different cough management options in adults and children with psychogenic, tic, and habit cough. Medline, EMBASE, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus were searched from the earliest inception of each database to September 2013. Content experts were contacted, and we searched bibliographies of included studies to identify additional references.

RESULTS

A total of 18 uncontrolled studies were identified, enrolling 223 patients (46% male subjects, 96% children and adolescents). Psychogenic cough was the most common descriptive term used (90% of the studies). Most of the patients (95%) had no cough during sleep; barking or honking quality of cough was described in only eight studies. Hypnosis (three studies), suggestion therapy (four studies), and counseling and reassurance (seven studies) were the most commonly used interventions. Hypnosis was effective in resolving cough in 78% of the patients and improving it in another 5%. Suggestion therapy resolved cough successfully in 96% of the patients. The greatest majority of improvements noted with these forms of therapy occurred in the pediatric age group. The quality of evidence is low due to the lack of control groups, the retrospective nature of all the studies, heterogeneity of definitions and diagnostic criteria, and the high likelihood of reporting bias.

CONCLUSIONS

Only low-quality evidence exists to support a particular strategy to define and treat psychogenic, habit, and tic cough. Patient values, preferences, and availability of potential therapies should guide treatment choice.

Inhibitory effect of cervical trachea and chest wall vibrations on cough reflex sensitivity and perception of urge-to-cough in healthy male never-smokers

BACKGROUND

Non-pharmacological options for symptomatic management of cough are desired. Although chest wall mechanical vibration is known to ameliorate cough reflex sensitivity, the effect of mechanical vibrations on perceptions of urge-to-cough has not been studied. Therefore, we investigated the effect of mechanical vibration of cervical trachea, chest wall and femoral muscle on cough reflex sensitivity, perceptions of urge-to-cough as well as dyspnea.

METHODS

Twenty-four healthy male never-smokers were investigated for cough reflex sensitivity, perceptions of the urge-to-cough and dyspnea with or without mechanical vibration. Cough reflex sensitivity and urge-to-cough were evaluated by the inhalation of citric acid. The perception of dyspnea was evaluated by Borg scores during applications of external inspiratory resistive loads. Mechanical vibration was applied by placing a vibrating tuning fork on the skin surface of cervical trachea, chest wall and femoral muscle.

RESULTS

Cervical trachea vibration significantly increased cough reflex threshold, as expressed by the lowest concentration of citric acid that elicited five or more coughs (C5), and urge-to-cough threshold, as expressed by the lowest concentration of citric acid that elicited urge-to-cough (Cu), but did not significantly affect dypnea sensation during inspiratory resistive loading. On the other hand, the chest wall vibration not only significantly increased C5 and Cu but also significantly ameliorated the load-response curve of dyspnea sensation.

CONCLUSIONS

Both cervical and trachea vibrations significantly inhibited cough reflex sensitivity and perception of urge-to-cough. These vibration techniques might be options for symptomatic cough management.

Upper esophageal sphincter and esophageal motility in patients with chronic cough and reflux: assessment by high-resolution manometry

The pathophysiology of chronic cough and its association with dsymotility and laryngopharyngeal reflux remains unclear. This study applied high-resolution manometry (HRM) to obtain a detailed evaluation of pharyngeal and esophageal motility in chronic cough patients with and without a positive reflux-cough symptom association probability (SAP). Retrospective analysis of 66 consecutive patients referred for investigation of chronic cough was performed. Thirty-four (52%) were eligible for inclusion (age 55 [19-77], 62% female). HRM (ManoScan 360, Given/Sierra Scientific Instruments, Mountain View, CA) with 10 water swallows was performed followed by a 24-hour ambulatory pH monitoring. Of this group, 21 (62%) patients had negative reflux-cough SAP (group A) and 13 (38%) had positive SAP (group B). Results from 23 healthy controls were available for comparison (group C). Detailed analysis revealed considerable heterogeneity. A small number of patients had pathological upper esophageal sphincter (UES) function (n=9) or esophageal dysmotility (n=1). The overall baseline UES pressure was similar, but average UES residual pressure was higher in groups A and B than in control group C (-0.2 and -0.8mmHg vs. -5.4mmHg; P<0.018 and P<0.005). The percentage of primary peristaltic contractions was lower in group B than in groups A and C (56% vs. 79% and 87%; P=0.03 and P<0.002). Additionally, intrabolus pressure at the lower esophageal sphincter was higher in group B than in group C (15.5 vs. 8.9; P=0.024). HRM revealed changes to UES and esophageal motility in patients with chronic cough that are associated with impaired bolus clearance. These changes were most marked in group B patients with a positive reflux-cough symptom association.

Improvement in health status following cough-suppression physiotherapy for patients with chronic cough

Cough-suppression physiotherapy is a novel self-help therapy for chronic cough. We evaluated the effectiveness of cough physiotherapy in a pilot prospective observational study. We assessed cough-specific health-related quality of life (HRQOL) with the Leicester Cough Questionnaire (LCQ) and subjectively reported cough frequency and sleep disturbance in 23 patients with chronic cough refractory to medical therapy, before and after outpatient-based cough-suppression physiotherapy. Cough-suppression physiotherapy consisted of education, counselling, cough control, breathing retraining, and vocal hygiene. There was a significant improvement in cough-specific HRQOL after cough physiotherapy; mean (standard error of mean [SEM]) LCQ total score before 12.4 (0.9) versus after 15.1 (0.9); 95% confidence interval of difference -4.1 to -1.3; p < 0.001. The improvement in cough-specific HRQOL was greater than the LCQ minimal clinically important difference of 1.3. A significant improvement was seen in all LCQ domains: physical (p = 0.001), psychological (p < 0.001) and social (p < 0.04). There was a significant reduction in cough frequency scores (p = 0.002) and sleep disturbance scores (p = 0.02). Our findings suggest cough-suppression physiotherapy may lead to a clinically significant improvement in cough-specific HRQOL in patients with chronic cough.

Pediatric cough: what the otolaryngologist needs to know

PURPOSE OF REVIEW

Pediatric cough is a common complaint in 35% of preschool children and 9% of 7-11-year-olds. The cause of the cough is often elusive. This review article presents a framework from which to approach the pediatric patient with chronic cough.

RECENT FINDINGS

The cause of cough in the pediatric patient is often allergy, postnasal drip, asthma, or infection. The existence of cough-variant asthma has been brought into question and evidence is detailed in this article.

SUMMARY

The treatment of chronic cough in a pediatric population should be approached from a multidisciplinary team consisting of pulmonologists, gastroenterologists, allergists, immunologists and otolaryngologists. Once a specific diagnosis is determined, treatment should be specific to that diagnosis.

Provision of primary care to patients with chronic cough in the community pharmacy setting

BACKGROUND

Community pharmacies are at the forefront of primary care providers and have an important role in the referral of patients to a medical practitioner for review when necessary. Chronic cough is a common disorder in the community and requires medical assessment. The proficiency of community pharmacy staff to refer patients with chronic cough is currently unknown.

OBJECTIVE

To assess the ability of community pharmacy staff to recognize and medically refer patients with a chronic nonproductive cough.

METHODS

Following ethics approval, a simulated patient study of 156 community pharmacies in Perth, Western Australia, was conducted over a 3-month period. Simulated patients presented to the pharmacy requesting treatment for a cough. The simulated patient required a referral based on a designated scenario. Demographic details, assessment questions, and advice provided were recorded by the simulated patient immediately postvisit. A logistic regression analysis was performed, with referral for medical assessment as the dependent variable.

RESULTS

Of the 155 community pharmacies included in the analysis, 38% provided appropriate medical referral. Cough suppressants were provided as therapy in 72% of all visits. Predictors of medical referral were assessment of symptom duration, medical history, current medications being taken, frequency of reliever use, and the position of the pharmacy staff member conducting the consultation. A third of community pharmacies provided appropriate primary care by recommending medical referral advice to patients with chronic cough. The majority of pharmacy staff members acquired information from the patient that suggested a need for medical referral, yet did not provide referral advice.

CONCLUSIONS

Appropriate medical referral is more likely when adequate assessment is undertaken and when a pharmacist is directly involved in the consultation. This highlights the need for pharmacies to ensure that processes are in place for patients to access the pharmacist.

Does gastroesophageal reflux scintigraphy correlate with clinical findings in children with chronic cough?

OBJECTIVE

Gastroesophageal reflux (GER), a common problem during childhood, leads to chronic troublesome symptoms including chronic respiratory symptoms. Therefore, timely diagnostic work-up for GER is essential in children when GER is suspected. In this study, we aimed to establish whether scintigraphic parameters have clinical importance in investigating the reflux in children.

METHODS

A total of 72 children older than 7 years with chronic cough of unknown etiology were enrolled for this study. The scintigraphic procedure was performed by using technetium-99m tin colloid (37-74 MBq). Cough and GER scores were used for children who were positive for GER both before and after GER treatment.

RESULTS

Of 72 children, 65 children with a mean age of 10.3+/-2.3 (7-19) years had GER on gastroesophageal scintigraphy. Median reflux episode number was 7 (1-14). There was a significantly positive correlation between reflux episode number and cough (r = 0.446, P<0.001) and GER score (r = 0.432, P<0.001). The significant decrease was observed in cough (from 3.5+/-1.9 to 1.6+/-1.3) and GER scores (from 4.1+/-2.5 to 1.3+/-1.1) with GER treatment (P<0.001 for each).

CONCLUSION

Scintigraphy should be used for the detection of GER in children who present with chronic cough. Increasing episode number in gastroesophageal scintigraphy might be a predictor for reflux-related symptom severity.

Modulation of sensory nerve function and the cough reflex: understanding disease pathogenesis

To cough is a protective defence mechanism that is vital to remove foreign material and secretions from the airways and which in the normal state serves its function appropriately. Modulation of the cough reflex pathway in disease can lead to inappropriate chronic coughing and an augmented cough response. Chronic cough is a symptom that can present in conjunction with a number of diseases including chronic obstructive pulmonary disease (COPD) and asthma, although often the cause of chronic cough may be unknown. As current treatments for cough have proved to exhibit little efficacy and are largely ineffective, there is a need to develop novel, efficacious and safe antitussive therapies. The underlying mechanisms of the cough reflex are complex and involve a network of events, which are not fully understood. It is accepted that the cough reflex is initiated following activation of airway sensory nerves. Therefore, in the hope of identifying novel antitussives, much research has focused on understanding the neural mechanisms of cough provocation. Experimentally this has been undertaken using chemical or mechanical tussive stimuli in conjunction with animal models of cough and clinical cough assessments. This review will discuss the neural mechanisms involved in the cough, changes that occur under pathophysiological conditions and and how current research may lead to novel therapeutic opportunities for the treatment of cough.

Clinical cough II: therapeutic treatments and management of chronic cough

Chronic cough is a common and frequently disruptive symptom which can be difficult to treat with currently available medicines. Asthma/eosinophilic airway disease and gastro-oesophageal reflux disease are most commonly associated with chronic cough but it may also trouble patients with chronic obstructive pulmonary disease, pulmonary fibrosis and lung cancer. Over the last three decades there have been a number of key advances in the clinical approach to cough and a number of international guidelines on the management of cough have been developed. Despite the undoubted benefit of such initiatives, more effective treatments for cough are urgently needed. The precise pathophysiological mechanisms of chronic cough are unknown but central to the process is sensitization (upregulation) of the cough reflex. One well-recognized clinical consequence of this hypersensitive state is bouts of coughing triggered by apparently trivial provocation such as scents and odours and changes in air temperature. The main objective of new treatments for cough would be to identify ways to downregulate this heightened cough reflex but yet preserve its crucial role in protecting the airway. The combined efforts of clinicians, scientists and the pharmaceutical industry offer most hope for such a treatment breakthrough. The aim of this chapter is to provide some rationale for the current treatment recommendations and to offer some reflections on the management of patients with chronic cough.

Chronic cough – occupational considerations

Chronic cough is a common symptom in a wide range of respiratory conditions, and may also occur as a result of upper airway or gastro-esophageal problems. Whilst chronic cough of any cause may be exacerbated by work, in some cases it has a direct occupational cause, resulting from a harmful acute or chronic workplace exposure. Such occupational conditions may only be suspected by taking a detailed occupational history, and directly asking employed patients whether their cough improves away from work. Early and accurate diagnosis, linked with tailored drug therapy, modification of workplace exposures, and expert compensation advice is likely to offer the best outcome for this group of patients.

Does idiopathic cough exist?

Despite a meticulous protocol involving diagnostic testing and trials of empirical therapy, there may be no obvious cause for a chronic cough in up to 42% of cases referred for specialist evaluation. In some cases, failure to consider causes that include the asthma/eosinophilic airway syndromes such as eosinophilic bronchitis and atopic cough, or nonacid gastroesophageal reflux disease may explain diagnostic failure. However, a distinct group of patients may be considered to have true idiopathic cough. Current published evidence suggests a certain patient phenotype, namely, middle-aged females with prolonged nonproductive cough and cough reflex hypersensitivity. Almost nothing else is known about this clinical entity and currently no specific therapy exists.