Classification of Cough as a Symptom in Adults and Management Algorithms: CHEST Guideline and Expert Panel Report

Impact and disease burden of chronic cough

Cough is an important physiological mechanism to protect the lower airways, but it is also one of the most common symptoms that lead patients to seek medical consultations. Chronic cough, usually defined by cough duration longer than 8 weeks in adults, is prevalent in the community and impairs quality of life in individual patients. There are several characteristics that may differentiate pathologic coughs from protective cough responses, including cough duration, frequency, hypersensitivity, impaired cough suppressibility, or treatment refractoriness. However, the impact of cough, or its perceived severity, is a sum of the patient's experience of coughing and is a factor that may finally define cough as a disease. Social isolation is a major impact of chronic cough, which is now worse due to the coronavirus disease 2019 pandemic and a widespread fear of cough as a source of contagion. Emotional impact and economic impact (medical cost, reduced work productivity, and job loss) are also important complications of chronic cough, and they interact in a vicious cycle, aggravated by social isolation and treatment failures. This paper is a narrative review that aims to address the impact and disease burden of chronic cough in adult patients. We review the literature, but also introduce the findings from recent qualitative interviews and the patients' experiences of the impact and burden of chronic cough and discuss unmet needs in these patients.

The competency of Indonesian pharmacy students in handling a self-medication request for a cough: a simulated patient study

Background

Cough is a common symptom for which people frequently present to community pharmacies. Previous articles from developing countries have shown that the provision of self-medication consultation for cough in community pharmacies were suboptimal, with knowledge deficiency being a contributing factor. However, little is known regarding the ability of pharmacy students in handling self-medication consultations in developing countries.

Objectives

To measure the competency of Indonesian pharmacy students in providing self-medication consultations for patients with chronic cough and to identify factors associated with the provision of appropriate advice.

Method

This study is a cross-sectional study. A simulated patient method using a product and a symptom-based request of chronic cough was used in students from a pharmacy school in Indonesia. The nature and amount of information gathered and advice provided by pharmacy students were noted and audio-recorded. A logistic regression analysis was performed to identify factors associated with the provision of appropriate advice.

Results

The information gathered by participating students was not comprehensive. The most common types of information gathered were related to the nature and duration of the cough. Information relating to accompanying symptoms, medications, and allergies was gathered in less than 60% of the participating students for both product and symptom based scenarios. The appropriate advice of direct medical referral was provided in 54% and 56% of the 183 participating students for the product and symptom-based request scenarios respectively. Asking about symptom duration and prior medical conditions were positively associated with the provision of appropriate advice in the symptom and product based requests respectively.

Conclusion

Student competency in self-medication consultation for chronic cough needs to be improved. Appropriate information-gathering is a predictor of appropriate advice. Further qualitative research identifying factors affecting students' competence in providing self-medication consultation is required, so that suitable interventions are developed and implemented.

Addressing unmet needs for diagnosis and management of chronic cough in the primary care setting

Chronic cough (i.e. cough lasting >8 weeks) has a global prevalence of approximately 10% and is associated with substantial patient burden, including social, psychological, and physical impairments. This burden can be long-lasting, with some patients experiencing cough for many years. Although chronic cough is often a symptom of respiratory diseases (e.g. interstitial lung disease, chronic obstructive pulmonary disease) or is associated with comorbid conditions (e.g. asthma, gastroesophageal reflux disease) and may resolve after targeted treatment of these conditions, some patients continue to cough despite optimal treatment of associated conditions (refractory chronic cough (RCC)) or have no identifiable conditions presumed to be contributing to the cough (unexplained chronic cough (UCC)). As both RCC and UCC are diagnoses of exclusion, it is critical to perform a thorough initial patient assessment with adherence to diagnostic guidelines to accurately identify RCC and UCC and provide appropriate treatment. Primary care physicians may be in an important position to provide the initial diagnostic workup of patients with chronic cough as well as identify when referral to specialists (e.g. pulmonologists, allergists, otolaryngologists) is appropriate. In this narrative review, current diagnosis and management guidelines for chronic cough are summarized and recommendations for diagnostic workup in a primary care setting are provided. Increased appreciation of chronic cough as a distinct condition, rather than as only a symptom of other diseases, may help overcome current challenges in diagnosing and managing chronic cough and reduce patient burden.

Characterization of Patients With Refractory or Unexplained Chronic Cough Participating in a Phase 2 Clinical Trial of the P2X3-Receptor Antagonist Gefapixant

Purpose

This analysis assesses clinical characteristics of patients with refractory chronic cough (RCC) or unexplained chronic cough (UCC) enrolled in a phase 2 study to better understand this patient population.

Methods

Patients with RCC/UCC lasting for ≥ 1 year and cough severity visual analog scale (VAS) score of > 40 mm at screening were eligible. Demographics, clinical characteristics, and medical history were collected at baseline. Cough-related measures included cough severity VAS, Cough Severity Diary (CSD), Leicester Cough Questionnaire (LCQ), and a structured cough-trigger questionnaire. Medication history included all medications 30 days before screening and chronic cough treatments within 1 year before screening. Data were summarized using descriptive statistics.

Results

Patients (N = 253; female, 76%; mean age, 60 years) had severe (mean cough severity VAS, 57.5 mm) and long-lasting (median duration, 11 years) cough. The most burdensome self-reported aspects included psychological and social factors (LCQ) and cough frequency and intensity (CSD). Patient-reported triggers were consistent with cough hypersensitivity (e.g., 95% to 96% reported irritation or tickle in throat). Common reported comorbidities included gastroesophageal reflux disease (GERD; 56%), allergic rhinitis (47%), and asthma (30%); 12% of patients had been diagnosed with all 3 conditions. The most common prior medications included inhaled or oral steroids (21%), antihistamines (15%), and antacids (15%).

Conclusion

Patients with RCC/UCC had severe, long-lasting, and burdensome cough with clinical features of cough hypersensitivity. Many patients had been diagnosed with GERD, allergic rhinitis, and asthma but had a persistent cough despite treatment of these conditions.

Trial registration: ClinicalTrials.gov, NCT02612610; registered November 20, 2015

Evaluation and Management Outcomes and Burdens in Patients with Refractory Chronic Cough Referred for Behavioral Cough Suppression Therapy

PURPOSE

The purpose of this study was to investigate the typical symptoms and medical management characteristics of adult patients with refractory chronic cough (RCC) who are referred to speech-language pathology (SLP) for behavioral cough suppression therapy (BCST) in order to estimate cost-effectiveness and efficiency of current practice patterns for this population.

METHODS

One hundred sixty-four (164) patients with RCC referred for BCST were surveyed. Patients completed an initial survey at BCST onset related to symptom pattern and prior treatment, including the Leicester Cough Questionnaire (LCQ). Every four to six weeks patients completed follow-up surveys to assess their response to BCST.

RESULTS

Mean age was 58 years (83.5% women). The majority of patients reported their cough began two or more years prior to BCST. Approximately half (49%) reported seeing four or more physicians (including primary care physicians) and being prescribed four or more medications (57%) prior to BCST. Medications targeting post-nasal drip (72%), reflux (70%), asthma (56%), and allergies (56%) were most commonly prescribed. BCST resulted in a clinically significant improvement in 70.1% of participants. The mean change in LCQ for those who improved with BCST was 6.61. Over half (58%) reported they were quite satisfied to completely satisfied with their treatment response. The average time from enrollment to study completion was 64 days.

CONCLUSION

The results of this study suggest early intervention with BCST may be a cost-effective and efficient option for patients with RCC.

Prevalence, incidence and characteristics of chronic cough among adults from the Canadian Longitudinal Study on Aging

The global prevalence of chronic cough is highly variable, ranging from 2% to 18%. There is a lack of data on the prevalence and incidence of chronic cough in the general population. The objective of this study was to investigate the prevalence and incidence of chronic cough in a sample of Canadian adults, and how these are influenced by age, sex, smoking, respiratory symptoms, medical comorbidities and lung function. Participants with chronic cough were identified from the Canadian Longitudinal Study on Aging (CLSA) based on self-reported daily cough in the past 12 months. This is a prospective, nationally generalisable, stratified random sample of adults aged 45-85 years at baseline recruited between 2011 and 2015, and followed-up 3 years later. The prevalence and incidence per 100 person-years are described, with adjustments for age, sex and smoking. Of the 30 097 participants, 29 972 completed the chronic cough question at baseline and 26 701 did so at follow-up. The prevalence of chronic cough was 15.8% at baseline and 17.6% at follow-up with 10.4-17.1% variation across seven provinces included in the CLSA comprehensive sample. Prevalence increased with age and current smoking, and was higher in males (15.2%), Caucasians (14%) and those born in North America, Europe or Oceania (14%). The incidence of chronic cough adjusted for age, sex and smoking was higher in males and in underweight and obese subjects. Subjects with respiratory symptoms, airway diseases, lower forced expiratory volume in 1 s (% predicted), cardiovascular diseases, psychological disorders, diabetes and chronic pain had a higher incidence of chronic cough. The prevalence and incidence of chronic cough is high in the CLSA sample with geographic, ethnic and gender differences, influenced by a number of medical comorbidities.

Herbal Medicine for Adult Patients with Cough Variant Asthma: A Systematic Review and Meta-Analysis

INTRODUCTION

Herbal medicine is commonly used by patients with chronic cough, but the role of herbal medicine for cough variant asthma (CVA) has not yet been clearly defined. For the first time, we performed a meta-analysis to integrate the current evidence of randomized controlled trials (RCTs) on this topic and assess the efficacy of herbal medicine in adults with CVA.

METHODS

A comprehensive search was conducted in electronic databases to identify RCTs of herbal medicine for adult CVA. Cochrane systematic review methods were followed, and the Grading of Recommendations Assessment, Development, and Evaluation was performed to evaluate the quality of evidence.

RESULTS

Twenty-eight RCTs were included. Compared with placebo, moderate-quality evidence from two studies showed that herbal medicine was associated with reduced cough symptom score (CSS) (MD -1.15 points; 95% CI, -1.67 to -0.63) and visual analogue scale (VAS) (MD -1.76 points; 95% CI, -2.66 to -0.86). Compared with montelukast, low- to moderate-quality evidence from 11 studies indicated that herbal medicine was associated with improved Leicester Cough Questionnaire (LCQ) (MD 2.38 points; 95% CI, 1.32 to 3.44), reduced CSS (SMD -0.81 points; 95% CI, -1.09 to -0.53), and VAS (MD -1.34 points; 95% CI, -1.82 to -0.86). There were no significant differences between herbal medicine and ICS plus bronchodilator.

CONCLUSIONS

In adults with CVA, herbal medicine may result in improved quality of life and reduced cough frequency and severity scores compared with placebo or montelukast. Herbal medicine was not better than ICS plus a bronchodilator but the evidence is very uncertain.

The Japanese respiratory society guidelines for the management of cough and sputum (digest edition)

Cough and sputum are common complaints at outpatient visits. In this digest version, we provide a general overview of these two symptoms and discuss the management of acute (up to three weeks) and prolonged/chronic cough (longer than three weeks). Flowcharts are provided, along with a step-by-step explanation of their diagnosis and management. Most cases of acute cough are due to an infection. In chronic respiratory illness, a cough could be a symptom of a respiratory infection such as pulmonary tuberculosis, malignancy such as a pulmonary tumor, asthma, chronic obstructive pulmonary disease, chronic bronchitis, bronchiectasis, drug-induced lung injury, heart failure, nasal sinus disease, sinobronchial syndrome, eosinophilic sinusitis, cough variant asthma (CVA), atopic cough, chronic laryngeal allergy, gastroesophageal reflux (GER), and post-infectious cough. Antibiotics should not be prescribed for over-peak cough but can be considered for atypical infections. The exploration of a single/major cause is recommended for persistent/chronic cough. When sputum is present, a sputum smear/culture (general bacteria, mycobacteria), cytology, cell differentiation, chest computed tomography (CT), and sinus X-ray or CT should be performed. There are two types of rhinosinusitis. Conventional sinusitis and eosinophilic rhinosinusitis present primarily with neutrophilic inflammation and eosinophilic inflammation, respectively. The most common causes of dry cough include CVA, atopic cough/laryngeal allergy (chronic), GER, and post-infectious cough. In the last chapter, future challenges and perspectives are discussed. We hope that the clarification of the pathology of cough hypersensitivity syndrome will lead to further development of "pathology-specific non-specific therapeutic drugs" and provide benefits to patients with chronic refractory cough.

Longitudinal Follow-up of Superior Laryngeal Nerve Block for Chronic Neurogenic Cough

Objective

To demonstrate longitudinal follow-up for patients who underwent in-office superior laryngeal nerve (SLN) block with lidocaine and steroids for chronic neurogenic cough.

Study Design

Longitudinal follow-up study over 10 months.

Setting

Clinical.

Methods

A retrospective review of 30 patients who underwent in-office nerve block to the SLN for neurogenic cough, including the 10 patients whose outcomes were originally published in 2019.

Results

Thirty patients in this study who underwent a series of SLN blocks showed significant improvement in cough severity index (CSI). The average number of blocks was 3 (range, 2-8). Twelve patients underwent initial SLN block to the left side and 18 patients underwent initial SLN block to the right side. The mean follow-up from the first SLN block was 5.3 months. The mean pretreatment and posttreatment CSI scores were 27 and 11, respectively, for all 30 patients who underwent an SLN block. A Wilcoxon signed rank test shows that there is a significant effect on CSI (W = 2, z = −4.659, P < .05). The mean longitudinal follow-up for the original 10 patients was 10 months from the first SLN block, with none of these patients receiving any further treatment for their cough.

Conclusion

Superior laryngeal nerve block is an effective long-term treatment for neurogenic cough. No additional treatment was required within 10 months of the SLN block.

Level of Evidence

Level IV.

Work-Related Upper-Airway Disorders

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

Gastroesophageal reflux and asthma: when, how, and why

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Consensus Guidelines for Evaluation and Management of Pulmonary Disease in Sjögren's

BACKGROUND

Pulmonary disease is a potentially serious yet underdiagnosed complication of Sjögren's syndrome, the second most common autoimmune rheumatic disease. Approximately 16% of patients with Sjögren's demonstrate pulmonary involvement with higher mortality and lower quality of life.

RESEARCH QUESTION

Clinical practice guidelines for pulmonary manifestations of Sjögren's were developed by the Sjögren's Foundation after identifying a critical need for early diagnosis and improved quality and consistency of care.

STUDY DESIGN AND METHODS

A rigorous and transparent methodology was followed according to American College of Rheumatology guidelines. The Pulmonary Topic Review Group (TRG) developed clinical questions in the PICO (Patient, Intervention, Comparison, Outcome) format and selected literature search parameters. Each article was reviewed by a minimum of two TRG members for eligibility and assessment of quality of evidence and strength of recommendation. Guidelines were then drafted based on available evidence, expert opinion, and clinical importance. Draft recommendations with a clinical rationale and data extraction tables were submitted to a Consensus Expert Panel for consideration and approval, with at least 75% agreement required for individual recommendations to be included in the final version.

RESULTS

The literature search revealed 1,192 articles, of which 150 qualified for consideration in guideline development. Of the original 85 PICO questions posed by the TRG, 52 recommendations were generated. These were then reviewed by the Consensus Expert Panel and 52 recommendations were finalized, with a mean agreement of 97.71% (range, 79%-100%). The recommendations span topics of evaluating Sjögren's patients for pulmonary manifestations and assessing, managing, and treating upper and lower airway disease, interstitial lung disease, and lymphoproliferative disease.

INTERPRETATION

Clinical practice guidelines for pulmonary manifestations in Sjögren's will improve early identification, evaluation, and uniformity of care by primary care physicians, rheumatologists, and pulmonologists. Additionally, opportunities for future research are identified.

A Symptom-Directed Paradigm for the Evaluation and Management of Upper Respiratory Tract Infections

Upper respiratory tract infections are one of the most common challenges in ambulatory medicine. Effective evaluation involves identification, primarily through the history, of the dominant set of patient symptoms leading to accurate diagnosis. Certain more morbid illnesses that mimic common upper respiratory symptoms can also be excluded with this approach. Treatment should address patient preferences through an understanding of the limited utility of antibiotics and through tailored advisement of the numerous pharmacologic options for symptom relief.

Cannabis use disorder and the lungs

Cannabis is one of the world's most widely used recreational drugs and the second most commonly smoked substance. Research on cannabis and the lungs has been limited by its illegal status, the variability in strength and size of cannabis cigarettes (joints), and the fact that most cannabis users also smoke tobacco, making the effects difficult to separate. Despite these difficulties, the available evidence indicates that smoking cannabis causes bronchitis and is associated with changes in lung function. The pattern of effects is surprisingly different from that of tobacco. Whereas smoking cannabis appears to increase the risk of severe bronchitis at quite low exposure, there is no convincing evidence that this leads to chronic obstructive pulmonary disease. Instead, cannabis use is associated with increased central airway resistance, lung hyperinflation and higher vital capacity with little evidence of airflow obstruction or impairment of gas transfer. There are numerous reports of severe bullous lung disease and pneumothorax among heavy cannabis users, but convincing epidemiological data of an increased risk of emphysema or alveolar destruction are lacking. An association between cannabis and lung cancer remains unproven, with studies providing conflicting findings.

Inflammatory Subtypes in Classic Asthma and Cough Variant Asthma

Background

Measurement of sputum is used to define airway inflammatory phenotypes. Cough variant asthma (CVA) is considered to be the initial stage of classic asthma (CA). The aim of this study was to describe the association between the different subtypes of CVA and CA.

Methods

A total of 459 patients with CVA and CA were screened for the study. All included patients performed spirometry, underwent a bronchial challenge with methacholine and induced sputum according to the guidelines.

Results

A higher frequency of female patients were found with CVA and the eosinophilic airway inflammation of CVA than in CA and the noneosinophilic airway inflammation of CA (p=0.004 and p=0.024, respectively). Bronchial hyper-responsiveness (BHR) was lower in eosinophilic CVA and CA (p=0.006), while no difference was found in noneosinophilic CVA and CA. Association between the percentage of sputum eosinophils and the FEV₁ level fell below 20% of the baseline value (PD₂₀) in CVA and CA (r= −0.1245, p=0.0357 and r= −0.2148, p=0.0014, respectively).

Conclusion

Eosinophilia may be associated with more severe disease, yet there was no difference in spirometry between the eosinophilic and noneosinophilic groups, and the BHR difference was not dramatic.

Prevalence and Characteristics of Chronic Cough in Adults Identified by Administrative Data

CONTEXT

International Classification of Diseases-9/10 codes for chronic cough (CC) do not exist, limiting investigation.

OBJECTIVE

To develop a computerized algorithm to determine CC prevalence and its characteristics.

DESIGN

This observational study using administrative data identified hierarchically patients aged 18 to 85 years with CC from 2013 to 2016. First, a specialist-diagnosed CC group was identified using an internal CC encounter code during an outpatient visit to a pulmonologist, allergist, otolaryngologist, or gastroenterologist. Subsequently, an event-diagnosed CC group was identified based on clinical notes through natural language processing, ICD-9/ICD-10 cough codes, and dispensed antitussives.

MAIN OUTCOME MEASURES

Prevalence of CC and comparison of clinical characteristics between specialist-diagnosed and event-diagnosed CC subgroups.

RESULTS

A total of 50,163 patients with CC of more than 8 weeks were identified. Of these, 11,290 (22.5%) were specialist diagnosed, and 38,873 (77.5%) were event diagnosed. The CC cohort was 57.4 ± 16.5 years of age; 67.6% were female. The overall prevalence was 1.04% (95% confidence interval = 1.03-1.06) in 2016. Prevalence in 2016 was higher in female patients (1.21%) than in male patients (0.81%), higher in patients aged 65 to 85 years (2.2%) than in patients aged 18 to 44 years (0.43%), and higher in Blacks (1.38%) than in Whites (1.21%). Compared with patients with event-diagnosed CC, patients with specialist-diagnosed CC exhibited significantly higher frequencies of laboratory tests and respiratory and nonrespiratory comorbidities and dispensed medication and lower frequency of pneumonia, all-cause and respiratory-cause emergency department visits and hospitalizations, and dispensed antitussives.

CONCLUSIONS

We identified a CC cohort using electronic data in a managed care organization. Prevalences varied by sex, age, and ethnicity. Clinical characteristics varied between specialist-diagnosed and event-diagnosed CC.

Patient-Reported Burden of Chronic Cough in a Managed Care Organization

BACKGROUND

The burden of chronic cough (CC) requires better understanding.

OBJECTIVE

To determine the severity, health status, and health care resource utilization among patients with CC identified by electronic health records on 2 visits separated by ≥1 year.

METHODS

Information on cough-related burden was collected through survey from patients with CC, including validated questionnaires (the cough health status Leicester Cough Questionnaire [LCQ], the cough hypersensitivity Hull Airway Reflux Questionnaire [HARQ], and the Cough Quality of Life Questionnaire [CQLQ]), CC-associated respiratory and gastrointestinal comorbidities, and treatment responses. Spearman correlation coefficients were reported to examine the associations among the LCQ, HARQ, and CQLQ. Patient demographics and patient-reported CC features were compared between males and females, and among ethnic groups using Robust Poisson regression models.

RESULTS

The survey was completed by 565 patients who were 64.8 ± 12.6 years, 75.8% female, and 60.4% white. CC duration was 8.6 ± 10.5 years with an average weekly severity of 5.3 ± 2.3 (maximum 10). The LCQ score was 11.3 ± 3.9 (maximum 21). The HARQ score was 33.3 ± 13.6 (normal ≤13). The CQLQ score was 56.9 ± 17.5 (maximum 112, worse with higher scores). The Spearman rank correlations were high between the LCQ and HARQ (-0.65), the LCQ and CQLQ (-0.80), and the HARQ and CQLQ (0.69). Patients with CC-associated respiratory and gastrointestinal comorbidities generally showed similar results regarding the above questionnaires. Treatment responses were suboptimal. Women compared with men and non-whites compared with whites reported significantly worse cough severity and poorer LCQ, HARQ, and CQLQ scores.

CONCLUSIONS

CC is self-reported as a burdensome condition, particularly in women and non-white minorities, which markedly affects daily living with inadequate response to treatments.

Management of chronic refractory cough in adults

Cough is a common respiratory symptom that is considered to be chronic when it lasts more than eight weeks. When severe, chronic cough may significantly impact an individual's quality of life, and such patients are frequently referred for specialist evaluation. Current international guidelines provide algorithms for the management of chronic cough: in most cases, treatment of the underlying disease is sufficient to improve or resolve cough symptoms. Severe chronic cough may significantly affect patients' quality of life and necessitate frequent referral for specialist evaluations. In this narrative review, we summarize non-pharmacologic and pharmacologic management of adult patients with chronic cough of known cause that persists after proper treatment (chronic refractory cough, CRC) or chronic cough of unknown cause in adult patients. If chronic cough persists even after treatment of the underlying disease, or if the chronic cough is not attributable to any cause, then a symptomatic approach with neuromodulators may be considered, with gabapentin as the first choice, and opioids or macrolides as alternatives. Speech pathology treatment and/or neuromodulators should be discussed with patients and alternative options carefully considered, taking into account risk/benefit. Novel promising drugs are under investigation (e.g. P2×3 inhibitors), but additional studies are needed in this field. Speech pathology can be combined with a neuromodulator to give an enhanced treatment response of longer duration suggesting that non-pharmacologic treatment may play a key role in the management of CRC.

Cough and Eosinophilia

Eosinophilic airway inflammation is observed in 30% to 50% of chronic cough sufferers. It is a common feature of asthma and upper airway cough syndrome, and it is required in the diagnosis of nonasthmatic eosinophilic bronchitis. Our understanding of the mechanisms underlying allergic and nonallergic eosinophilic inflammation have evolved tremendously in the last 2 decades, but the cause of this inflammation in any individual is often uncertain. Inhaled corticosteroids are the mainstay therapy for cough due to asthma or nonasthmatic eosinophilic bronchitis, and response is related to the presence of biomarkers of eosinophilic airway inflammation. In upper airway cough syndrome, nasal topical corticosteroids are beneficial in allergic rhinitis and chronic rhinosinusitis with polyposis. This review will describe the diagnosis, current and possible future treatments, and prognosis of chronic cough in adults with eosinophilic inflammation.

Looking ahead to novel therapies for chronic cough. Part 1 - peripheral sensory nerve targeted treatments

INTRODUCTION

Due to a relatively high prevalence and negative impact on quality of life chronic cough (CC) is a challenge for both patients and clinicians. There is ongoing research to address the unmet need and develop more effective antitussive treatment options. This is the first part of a series of two reviews of new antitussive medications. Medical databases (Medline, Embase and SCOPUS) and trial registries (ClinicalTrials.gov and EudraCT) were searched for studies on antitussive drugs targeting peripheral sensory nerves.

AREAS COVERED

This review presents current knowledge of peripheral receptors that are not only involved in evoking the cough reflex, but are also potentially responsible for more sustained neural alterations. Blockage of the receptors and ion channels is discussed in terms of its potential antitussive effect.

EXPERT OPINION

Although better understanding of CC mechanisms has facilitated the development of novel treatments including P2X2/3 receptor inhibitors (e.g. gefapixant), there remain several gaps in the knowledge about the mechanisms and treatment of CC. These include the lack of tests to diagnose cough hypersensitivity syndrome and predictors of response to specific treatments. Further research into cough phenotypes and endotypes will yield important insights and a personalized approach to cough management.

Perspectives on chronic cough in Korea

Chronic cough is a common condition, and generally affects about 3% of Korean adults with a significant influence on quality of life (QoL). Despite continued clinical and academic efforts, there are unmet needs for chronic cough prevention and management in Korea. Epidemiologically, there are two major challenges: an aging population and air pollution. Korea is one of the most rapidly aging countries, and the relative proportion of elderly to younger people is expected to double within the next two decades. Air pollution is a major concern, but there is very limited evidence on the effects of air pollutant on cough in Korean patients. Clinically, upper and lower airway diseases, such as rhinitis/rhinosinusitis and cough variant asthma/eosinophilic bronchitis, are reported to account for about 75% of chronic cough in Korean adults, which formed the basis in formulating clinical practice guidelines. However, further studies are warranted to resolve clinical uncertainty, particularly for the evaluation and treatment of upper airway conditions in chronic cough. The prevalence of gastroesophageal reflux disease (GERD) is increasing, thus its relevance to cough among Koreans may warrant re-evaluation. Infection-associated chronic cough, such as tuberculosis, is another continuing concern. The proportion of chronic refractory or unexplained cough is assumed to be 10–20% among patients visiting referral clinics for chronic cough. This review presents our perspectives on current epidemiological and clinical issues of chronic cough in Korea, and addresses major knowledge gaps and future research priorities.

Cough as an adverse effect on inhalation pharmaceutical products

Cough is an adverse effect that may hinder the delivery of drugs into the lungs. Chemical or mechanical stimulants activate the transient receptor potential in some airway afferent nerves (C-fibres or A-fibres) to trigger cough. Types of inhaler device and drug, dose, excipients and formulation characteristics, including pH, tonicity, aerosol output and particle size may trigger cough by stimulating the cough receptors. Release of inflammatory mediators may increase the sensitivity of the cough receptors to stimulants. The cough-provoking effect of aerosols is enhanced by bronchoconstriction in diseased airways and reduces drug deposition in the target pulmonary regions. In this article, we review the factors by which inhalation products may cause cough.

Should computed tomography and bronchoscopy be routine examinations for chronic cough?

Chronic cough is a common symptom of many diseases. Guidelines on cough from different countries recommend chest X-ray as the first-line examination. However, as compared to computerized tomography (CT), chest X-ray is insensitive in the diagnosis of many diseases. We speculate that CT is more helpful in excluding the causes of long-term cough, such as bronchial tumors and pulmonary interstitial diseases, which prevents patients from receiving unnecessary examinations and diagnostic treatments for chronic cough. In addition, a single chest CT is safe and affordable in some regions. Therefore, chest CT may be recommended as a first-line examination for patients with chronic cough. In addition, although bronchoscopy is employed as a further examination for chronic cough, it plays an important role in the diagnosis of chronic cough, especially in rare bronchial diseases such as amyloidosis and foreign body inhalation. Induced sputum cytology was not accepted as a necessary examination for chronic cough, but it becomes a first-line examination until physicians recognize that non-asthmatic eosinophilic bronchitis is a common cause of chronic cough. Therefore, we speculate that the roles of chest CT and bronchoscopy in the identification of causes of chronic cough are increasingly important; in some regions, or for patients suspicious for uncommon causes of chronic cough, CT and bronchoscopy are recommended as first-line examinations.

Mechanisms and Rationale for Targeted Therapies in Refractory and Unexplained Chronic Cough

Chronic cough, defined as a cough lasting > 8 weeks, is a common medical condition that exerts a substantial physical, mental, and social burden on patients. A subset of patients with chronic cough are troubled with a cough that persists despite optimal treatment of presumed associated common and uncommon conditions (refractory chronic cough; RCC) or in which no diagnosable cause for cough can be identified despite extensive assessment (unexplained chronic cough; UCC). Many of these patients exhibit clinical features of cough hypersensitivity, including laryngeal paresthesia, hypertussia, and allotussia. Over-the-counter cough remedies are ineffective and can lead to intolerable side effects when used for RCC/UCC, and the lack of approved treatments indicated for these conditions reflects a major unmet need. An increased understanding of the anatomy and neurophysiology of protective and pathologic cough has fostered a robust clinical development pipeline of several targeted therapies for RCC/UCC. This manuscript reviews the mechanisms presumed to underly RCC/UCC together with the rationale and clinical evidence for several targeted therapies currently under clinical investigation, including transient receptor potential channel antagonists, P2X3-receptor antagonists, voltage-gated sodium channel blockers, neuromodulators, and neurokinin-1-receptor antagonists. Finally, we provide an overview of targets that have been investigated in preclinical models of cough and other airway diseases that may hold future promise for clinical studies in RCC/UCC. Development of targeted therapies with different sites of action may foster a precision medicine approach to treat this heterogeneous, underserved patient population.

Cluster analysis in 975 patients with current cough identifies a phenotype with several cough triggers, many background disorders, and low quality of life

BACKGROUND

Recognition of disorder phenotypes may help to estimate prognosis and to guide the clinical management. Current cough management guidelines classify patients according to the duration of the cough episode. However, this classification is not based on phenotype analyses. The present study aimed to identify cough phenotypes by clustering.

METHODS

An email survey among employed, working-age subjects identified 975 patients with current cough. All filled in a comprehensive 80-item questionnaire including the Leicester Cough Questionnaire. Phenotypes were identified utilizing K-means partitional clustering. A subgroup filled in a follow-up questionnaire 12 months later to investigate the possible differences in the prognosis between the phenotypes.

RESULTS

Two clusters were found. The cluster A included 608 patients (62.4% of the population) and the cluster B 367 patients (37.6%). The three most important variables to separate the clusters were the number of the triggers of cough (mean 2.63 (SD 2.22) vs. 6.95 (2.30), respectively, p < 0.001), the number of the cough background disorders (chronic rhinosinusitis, current asthma, gastroesophageal reflux disease, 0.29 (0.50) vs. 1.28 (0.75), respectively, p < 0.001), and the Leicester Cough Questionnaire physical domain (5.33 (0.76) vs. 4.25 (0.84), respectively, p < 0.001). There were significant interrelationships between these three variables (each p < 0.001). Duration of the episode was not among the most important variables to separate the clusters. At 12 months, 27.0% of the patients of the cluster A and 46.1% of the patients of the cluster B suffered from cough that had continued without interruptions from the first survey (p < 0.001).

CONCLUSIONS

Two cough phenotypes could be identified. Cluster A represents phenotype A, which includes the majority of patients and has a tendency to heal by itself. The authors propose that cluster B represents phenotype TBQ (Triggers, Background disorders, Quality of life impairment). Given the poor prognosis of this phenotype, it urges a prompt and comprehensive clinical evaluation regardless of the duration of the cough episode.

The causes of acute cough: a tertiary-care hospital study in Japan

OBJECTIVES

Cough is the most frequent presenting complaint in general practice and has an adverse effect on an individual's well-being. Understanding the causes of cough is critical for appropriate patient management. According to its duration, cough is classified as acute, subacute, and chronic. While acute respiratory infection is considered to be the major cause of acute cough, there is little evidence.

METHODS

We retrospectively assessed the prevalence of acute cough in all patients presenting with cough to the respiratory clinic of Japanese Red Cross Wakayama Medical Center from May 2018 to April 2019. We subsequently assessed the causes of acute cough, after stratifying patients with acute cough into two subgroups based on the chest X-ray findings.

RESULTS

Among 685 patients (329 males; mean age, 61.8 ± 18.6 years) who presented with cough as a chief complaint, 274 (125 males; mean age, 57.6 ± 20.9 years) reported to have acute cough; chest X-ray abnormalities were detected in 113 of these patients. The most frequent cause of acute cough among 113 patients with chest X-ray abnormalities was pneumonia (55.8%), followed by lung cancer (9.7%) and pneumonia exacerbating asthma (7.1%). Among the 161 patients with acute cough without chest X-ray abnormalities, the most frequent cause was upper respiratory tract infection (57.1%), followed by asthma (23.6%) and cough variant asthma (6.2%).

CONCLUSIONS

Cough is the most frequent presenting complaint in general practice. Infections are the most frequent causes of acute cough regardless of the chest X-ray findings.

ACEI-induced cough: A review of current evidence and its practical implications for optimal CV risk reduction

Cough is one of the common adverse effects in patients receiving angiotensin-converting enzyme inhibitors (ACEIs). This review presents the current evidence on incidence and mechanisms of cough associated with ACEIs use, and proposes a practical approach for managing the same for optimal cardiovascular (CV) risk reduction. The incidence of dry cough in patients receiving ACEIs vary among individual ACEIs, and is the lowest with perindopril. Cough is thought to originate from multiple mechanisms, bradykinin theory is the most commonly appealed hypothesis. The strategies for optimal management could be temporarily discontinuation of ACEI upon a reported incidence of cough and reintroduction after its remission. However, studies have reported disappearance of cough despite continuing treatment. Another important approach could be adding calcium channel blockers to ACEIs. Switching to alternative drugs such as angiotensin receptor blockers should be suggested in case intolerable symptoms recur and after exclusion of all other possible causes of cough.

Extra-Esophageal Presentation of Gastroesophageal Reflux Disease: 2020 Update

Gastroesophageal reflux disease (GERD) is defined by the presence of symptoms induced by the reflux of the stomach contents into the esophagus. Although clinical manifestations of GERD typically involve the esophagus, extra-esophageal manifestations are widespread and less known. In this review, we discuss extra-esophageal manifestations of GERD, focusing on clinical presentations, diagnosis, and treatment. Common extra-esophageal manifestations of GERD include chronic cough, asthma, laryngitis, dental erosions, and gingivitis. Extra-esophageal involvement can be present also when classic GERD symptoms are absent, making the diagnosis more challenging. Although available clinical studies are heterogeneous and frequently of low quality, a trial with proton pump inhibitors can be suggested as a first-line diagnostic strategy in case of suspected extra-esophageal manifestations of GERD.

Chronic cough in adults

Cough, a defense mechanism for clearing the airways of secretions, exudate, or foreign bodies, may become a troublesome symptom. Chronic cough, one of the most frequent symptoms requiring medical attention, is often not due to identifiable causes in adults. Chronic productive cough defines chronic bronchitis, and thus is present in 100% of these patients, and frequently in patients with bronchiectasis, cystic fibrosis, and chronic infectious respiratory diseases. However, chronic cough is most frequently dry. Thus, chronic cough in adults is a difficult syndrome requiring multidisciplinary approaches, particularly to diagnose and treat the most frequent identifiable causes, but also to decide which patients may benefit by treating the central cough hypersensitivity by neuromodulatory therapy and/or non-pharmacologic treatment (speech pathology therapy). Recent guidelines provide algorithms for diagnosis and assessment of cough severity; particularly chronic cough in adults. After excluding life-threatening diseases, chronic cough due to identifiable causes (triggers and/or diseases), particularly smoking and/or the most frequent diseases (asthma, chronic bronchitis, chronic obstructive pulmonary disease, eosinophilic bronchitis, and adverse reactions to drugs [angiotensin-converting enzyme inhibitors and sitagliptin]) should be treated by avoiding triggers and/or according to guidelines for each underlying disease. In patients with troublesome chronic cough due to unknown causes or persisting even after adequate avoidance of triggers, and/or treatment of the underlying disease(s), a symptomatic approach with neuromodulators and/or speech pathology therapy should be considered. Additional novel promising neuromodulatory agents in clinical development (e.g., P2X3 inhibitors) will hopefully become available in the near future.

Diagnosis and management of chronic cough: similarities and differences between children and adults

Cough is a natural process that protects the airway. Cough can occur spontaneously or voluntarily. It is considered chronic when it is present for longer than 4 weeks in children or 8 weeks in adults. In both, chronic cough causes patient distress and increased healthcare utilization. Etiologies of pediatric chronic cough include asthma, protracted bacterial bronchitis, tracheomalacia, habit cough, and various systemic disorders. While some diagnoses are identifiable by careful history alone, others require testing guided by specific pointers. Flexible fiberoptic bronchoscopy has been an important tool to identify etiologies of chronic cough that were not otherwise apparent. In adults, asthma and bronchitis are well-defined etiologies of chronic cough, but much chronic cough in adults is largely a conundrum.

Reviews of adult chronic cough report that at least 40% of adults with chronic cough have no medical explanation. Gastroesophageal reflux and upper airway cough syndrome (a.k.a. post-nasal drip) have been common diagnoses of chronic cough, but those diagnoses have no support from controlled clinical trials and have been subjected to multiple published critiques. Cough hypersensitivity is considered to be an explanation for chronic cough in adults who have no other confirmed diagnosis. Gabapentin, a neuromodulator, has been associated with a modest effect in adults, as has speech pathology. While habit cough has not generally been a diagnosis in adults, there is evidence for a behavioral component in adults with chronic cough. Treatment for a specific diagnosis provides a better outcome than trials of cough suppression in the absence of a specific diagnosis. More data are needed for chronic cough in adults to examine the hypothesized cough hypersensitivity and behavioral management. This article reviews etiologies and the treatment of chronic cough in children and the conundrum of diagnosing and treating chronic cough in adults.

Rhinitis 2020: A practice parameter update

This comprehensive practice parameter for allergic rhinitis (AR) and nonallergic rhinitis (NAR) provides updated guidance on diagnosis, assessment, selection of monotherapy and combination pharmacologic options, and allergen immunotherapy for AR. Newer information about local AR is reviewed. Cough is emphasized as a common symptom in both AR and NAR. Food allergy testing is not recommended in the routine evaluation of rhinitis. Intranasal corticosteroids (INCS) remain the preferred monotherapy for persistent AR, but additional studies support the additive benefit of combination treatment with INCS and intranasal antihistamines in both AR and NAR. Either intranasal antihistamines or INCS may be offered as first-line monotherapy for NAR. Montelukast should only be used for AR if there has been an inadequate response or intolerance to alternative therapies. Depot parenteral corticosteroids are not recommended for treatment of AR due to potential risks. While intranasal decongestants generally should be limited to short-term use to prevent rebound congestion, in limited circumstances, patients receiving regimens that include an INCS may be offered, in addition, an intranasal decongestant for up to 4 weeks. Neither acupuncture nor herbal products have adequate studies to support their use for AR. Oral decongestants should be avoided during the first trimester of pregnancy. Recommendations for use of subcutaneous and sublingual tablet allergen immunotherapy in AR are provided. Algorithms based on a combination of evidence and expert opinion are provided to guide in the selection of pharmacologic options for intermittent and persistent AR and NAR.

P2X3-Receptor Antagonists as Potential Antitussives: Summary of Current Clinical Trials in Chronic Cough

Cough is among the most common complaints for which patients worldwide seek medical attention. In a majority of patients with chronic cough (defined as cough of greater than 8 weeks' duration), successful management results from a thorough evaluation and treatment of underlying causes. In a subgroup of patients, however, cough proves refractory to therapeutic trials aimed at known reversible causes of chronic cough. Such patients are appropriately termed as having refractory chronic cough. At present, safe and effective medications are lacking for this challenging patient population. Currently available therapeutic options are usually ineffective or achieve antitussive effect at the expense of intolerable side effects, typically sedation. Fortunately, the past decade has witnessed great progress in elucidating underlying mechanisms of cough. From that knowledge, aided by the development of validated instruments to measure objective and subjective cough-related end points, numerous antitussive drug development programs have emerged. The most active area of inquiry at present involves antagonists of the purinergic P2X receptors. Indeed, four clinical programs (one in Phase 3 and three in Phase 2) are currently underway investigating antagonists of receptors comprised entirely or partially of the P2X3 subunit as potential antitussive medications. Herein we review the foundation on which P2X receptor antagonists were developed as potential antitussive medications and provide an update on current clinical trials.

Palliative care in pulmonary medicine

Palliative care was initially developed for patients with advanced cancer. The concept has evolved and now encompasses any life-threatening chronic disease. Studies carried out to compare end-of-life symptoms have shown that although symptoms such as pain and dyspnea are as prevalent in patients with lung disease as in patients with cancer, the former receive less palliative treatment than do the latter. There is a need to refute the idea that palliative care should be adopted only when curative treatment is no longer possible. Palliative care should be provided in conjunction with curative treatment at the time of diagnosis, by means of a joint decision-making process; that is, the patient and the physician should work together to plan the therapy, seeking to improve quality of life while reducing physical, psychological, and spiritual suffering.

Treatable traits in chronic rhinosinusitis with nasal polyps

PURPOSE OF REVIEW

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex inflammatory sinonasal disease that deserves a multidisciplinary precision medicine approach. In a precision medicine model, a more pragmatic approach taking in consideration disease features that are potentially treatable should be considered.

RECENT FINDINGS

Several treatable traits in CRSwNP can be identified: from disease-related ones, to extra-ENT features, to behavioral and environmental factors. This review article summarizes primarily the recent findings of CRSwNP-related treatable traits and how they can be modified by given treatments.

SUMMARY

The advent of biological agents acting directly to the endotype underlying CRSwNP pushes the scientific community to integrate clinical, surgical and immunological evaluations for each single patient; this naturally leads to the identification of specific treatable traits that can serve as possible outcomes for any single biological.

Recent progress in the management of chronic cough

Chronic cough is a common clinical condition with significant impact on quality of life and for which effective therapy remains an unmet clinical need. Over the past decade, there has been a major shift in how we approach this problem, driven by better appreciation of the clinical manifestation of chronic cough and an improved understanding of the associated neurobiology. "Cough hypersensitivity syndrome" has been proposed as a new diagnostic term for chronic cough, encompassing different phenotypes of the condition. Accumulating evidence suggests that this new concept is clinically relevant. However, while it is gaining widespread endorsement within the allergy and respiratory community, raising its profile in routine clinical practice is a priority. Thus, the present paper reviews recent progress in our understanding and management of chronic cough, with focus on mechanistic and clinical studies. It also provides detail on knowledge gaps and future research directions.

AI4COVID-19: AI enabled preliminary diagnosis for COVID-19 from cough samples via an app

BACKGROUND

The inability to test at scale has become humanity's Achille's heel in the ongoing war against the COVID-19 pandemic. A scalable screening tool would be a game changer. Building on the prior work on cough-based diagnosis of respiratory diseases, we propose, develop and test an Artificial Intelligence (AI)-powered screening solution for COVID-19 infection that is deployable via a smartphone app. The app, named AI4COVID-19 records and sends three 3-s cough sounds to an AI engine running in the cloud, and returns a result within 2 min.

METHODS

Cough is a symptom of over thirty non-COVID-19 related medical conditions. This makes the diagnosis of a COVID-19 infection by cough alone an extremely challenging multidisciplinary problem. We address this problem by investigating the distinctness of pathomorphological alterations in the respiratory system induced by COVID-19 infection when compared to other respiratory infections. To overcome the COVID-19 cough training data shortage we exploit transfer learning. To reduce the misdiagnosis risk stemming from the complex dimensionality of the problem, we leverage a multi-pronged mediator centered risk-averse AI architecture.

RESULTS

Results show AI4COVID-19 can distinguish among COVID-19 coughs and several types of non-COVID-19 coughs. The accuracy is promising enough to encourage a large-scale collection of labeled cough data to gauge the generalization capability of AI4COVID-19. AI4COVID-19 is not a clinical grade testing tool. Instead, it offers a screening tool deployable anytime, anywhere, by anyone. It can also be a clinical decision assistance tool used to channel clinical-testing and treatment to those who need it the most, thereby saving more lives.

Giant cell arteritis manifested by chronic dry cough

A 77-year-old man visited the hospital with a chronic cough persisting for 2.5 months accompanied with night sweats, weight loss (3.5 kg) and elevated C-reactive protein level. Chest CT of the lung field was normal, but aortic wall thickening accompanied by a contrast effect was noted. Positron emission tomography-CT (PET-CT) showed that the aorta and subclavian artery were inflamed, suggesting large-vessel vasculitis. Ultrasonography showed thickening of the superficial temporal artery wall (macaroni sign). Biopsy revealed lymphocytic infiltration in the tunica media and foreign-body giant cell reaction with the elastic lamina, resulting in a diagnosis of giant cell arteritis (GCA). The cough was considered a symptom of GCA as it resolved following prednisolone administration. Cough may rarely be an initial GCA symptom. However, for chronic cough accompanied with elevated inflammatory findings but with a normal lung field, imaging studies such as PET-CT are useful for the differential diagnosis.

Life-Threatening and Non-Life-Threatening Complications Associated With Coughing: A Scoping Review

BACKGROUND

This is an update of the section on complications that are associated with coughing in the 2006 CHEST cough guidelines that addresses two aims: (1) to systematically identify and thematically categorize the diverse complications of cough by providing a guide for future studies and (2) to identify gaps in the literature for future research.

RESEARCH QUESTION

What are the potential complications that are associated with the act of coughing that have been reported in infants, children, adolescents, and adults?

STUDY DESIGN AND METHODS

A scoping review was performed with the use of PubMed and SCOPUS databases that were searched from their beginning until September 6, 2019.

RESULTS

Two hundred forty-seven publications met our inclusion criteria. To these, we added 38 articles from the 2006 complications paper that were not identified in the literature search plus the paper itself for a final total of 286 publications that formed the basis of this review. Since 2006, three new categories of complications have been reported: ear, nose and throat; disease transmission; and laboratory testing. Multiple additional complications that fall outside of these three categories have also been identified and included in the following categories: cardiovascular, constitutional symptoms, dermatologic, GI, genitourinary, musculoskeletal, neurologic, ophthalmologic, psychosocial/quality of life, and respiratory. Not previously highlighted is that some of the complications led to serious morbidity that included death, especially in patients with comorbid conditions, and potentially resulted in harm to others when cough resulted in a motor vehicle accident.

INTERPRETATION

Our work identified a large number of cough complications that we thematically categorized primarily by organ system so that future studies of each system or each complication can be conducted. The gap in the literature that future studies should address is to identify the frequency of the complications and the strength of their association with cough. Only then will one be able to describe the findings in a manner that allows specific recommendations for avoiding these complications. In the meantime, patients with cough should be evaluated and treated according to evidence-based guidelines to mitigate or prevent the myriad of potential complications that are associated with coughing.

Chronic cough related to the upper airway cough syndrome: one entity but not always the same

Purpose

Upper airway cough syndrome (UACS), described as chronic cough (CC) associated with allergic (AR), non-allergic rhinitis (NAR) or chronic rhinosinusitis (CRS), is one of the major causes of CC. We aimed to characterize a cohort of UACS patients with special attention to differences between patients with AR and NAR.

Methods

A prospective analysis of clinical data of patients, diagnosed with UACS between 2015 and 2018.

Results

There were 143 patients diagnosed with UACS, median age 52 years, women predominance (68.5%), The group comprised of 59 (41%) AR and 84 (59%) NAR subjects, CRS diagnosed in 17 (12%). Median cough duration: 48 months (IQR 24–120), median cough severity (VAS)—60 mm (IQR 42–78), median Leicester Cough Questionnaire (LCQ) score—11.3 (IQR 8.7–13.7), never-smokers: 70%. The most common symptoms: PND (62%), rhinorrhea (59%), nasal congestion (54%), abnormalities of sinus CT: septum deviation (62%), turbinates hypertrophy (53%), mucosal thickening (53%). UACS as the only cause of CC, was presented in 20 patients (14%). We found no differences between patients with AR and NAR in terms of age, gender, duration and severity of cough, BMI, blood eosinophil count, total IgE and FeNO. AR was associated with higher comorbidity of asthma than NAR (54% vs 35%, p = 0.019). Abnormalities in sinus CT scan were more frequently found in patients with NAR than AR (p = 0.018).

Conclusion

NAR is the most common upper airway disease associated with UACS. Clinical characteristics of UACS patients with AR and NAR are similar with only minor differences between these groups. It seems reasonable to plan further studies concerning relationship of NAR and cough sensitivity, also in terms of potential similar neurogenic mechanism.

Diagnoses and management of adult cough: An Indian Environmental Medical Association (EMA) position paper

BACKGROUND

Cough is a common yet distressing symptom that results in significant health care costs from outpatient visits and related consultations.

OBJECTIVE

The understanding of the pathobiology of cough in recent times has undergone an evolution with Cough hypersensitivity syndrome (CHS) being suggested in most cases of dry cough. However, in the case of productive cough, ancillary mechanisms including impaired Mucociliary clearance, in addition to hypermucosecretory bronchospastic conditions of Smoker's cough, asthma-COPD overlap, bronchiectasis, and allergic bronchopulmonary aspergillosis, need to be critically addressed while optimizing patient care with symptomatic therapy in outpatient settings of India.

METHODS

In this review, evidence-based graded recommendations on use of antitussives - & protussives as a Position Paper were developed based on the Level and Quality of Scientific evidence as per Agency for Health Care and Quality (AHRQ) criteria listing and Expert opinions offered by a multidisciplinary EMA panel in India.

RESULTS

Management of acute or chronic cough involves addressing common issues of environmental exposures and patient concerns before instituting supportive therapy with antitussives or bronchodilatory cough formulations containing mucoactives, anti-inflammatory, or short-acting beta-2 agonist agents.

CONCLUSION

The analyses provides a real world approach to the management of acute or chronic cough in various clinical conditions with pro- or antitussive agents while avoiding their misuse in empirical settings.

A role for neurokinin 1 receptor expressing neurons in the paratrigeminal nucleus in bradykinin-evoked cough in guinea-pigs

KEY POINTS

Airway projecting sensory neurons arising from the jugular vagal ganglia terminate centrally in the brainstem paratrigeminal nucleus, synapsing upon neurons expressing the neurokinin 1 receptor. This study aimed to assess the involvement of paratrigeminal neurokinin 1 receptor neurons in the regulation of cough, breathing and airway defensive responses. Lesioning neurokinin 1 receptor expressing paratrigeminal neurons significantly reduced cough evoked by inhaled bradykinin but not inhaled ATP or tracheal mechanical stimulation. The reduction in bradykinin-evoked cough was not accompanied by changes in baseline or evoked respiratory variables (e.g. frequency, volume or timing), animal avoidance behaviours or the laryngeal apnoea reflex. These findings warrant further investigations into targeting the jugular ganglia and paratrigeminal nucleus as a therapy for treating cough in disease.

ABSTRACT

Jugular vagal ganglia sensory neurons innervate the large airways and are thought to mediate cough and associated perceptions of airway irritations to a range of chemical irritants. The central terminals of jugular sensory neurons lie within the brainstem paratrigeminal nucleus, where postsynaptic neurons can be differentiated based on the absence or presence of the neurokinin 1 (NK1) receptor. Therefore, in the present study, we set out to test the hypothesis that NK1 receptor expressing paratrigeminal neurons play a role in cough evoked by inhaled chemical irritants. To test this, we performed selective neurotoxin lesions of NK1 receptor expressing neurons in the paratrigeminal nucleus in guinea-pigs using substance P conjugated to saporin (SSP-SAP). Sham lesion control or SSP-SAP lesion guinea-pigs received nebulised challenges, with the pan-nociceptor stimulant bradykinin or the nodose ganglia specific stimulant adenosine 5'-triphosphate (ATP), in conscious whole-body plethysmography to study cough and associated behaviours. Laryngeal apnoea reflexes and cough evoked by mechanical stimulation of the trachea were additionally investigated in anaesthetised guinea-pigs. SSP-SAP significantly and selectively reduced the number of NK1 receptor expressing neurons in the paratrigeminal nucleus. This was associated with a significant reduction in bradykinin-evoked cough, but not ATP-evoked cough, mechanical cough or laryngeal apnoeic responses. These data provide further evidence for a role of jugular vagal pathways in cough, and additionally suggest an involvement of NK1 receptor expressing neurons in the paratrigeminal nucleus. Therefore, this neural pathway may provide novel therapeutic opportunities to treat conditions of chronic cough.

Management of Respiratory Symptoms in Those with Serious Illness

Respiratory symptoms are common in patients living with serious illness, both in cancer and nonmalignant conditions. Common symptoms include dyspnea (breathlessness), cough, malignant pleural effusions, airway secretions, and hemoptysis. Basic management of respiratory symptoms is within the scope of primary palliative care. There are pharmacologic and nonpharmacologic approaches to treating respiratory symptoms. This article provides clinicians with treatment approaches to these burdensome symptoms.

The Wide-Ranging Spectrum of Cough-Induced Complications and Patient Harm

Cough is one of the most common complaints encountered in every setting; however, complications associated with coughing have received relatively little attention. An exhaustive systematic review of the English literature revealed an exceedingly large and varied spectrum of cough-induced complications affecting many systems, including upper airways, chest wall and thorax, abdominal wall, heart and aorta, central nervous system, eye, gastrointestinal tract, urogenital system, and emotional and psychological harm. Prospective studies and prevalence data are conspicuously missing. Reported cough-induced pathology ranges from rare (the majority) to common and from trivial (eg, lightheadedness, subconjunctival hemorrhage) to severe and life-threatening (eg, cervical artery dissection, rupture of a normal spleen). Other seemingly benign entities may mask a serious underlying pathology (eg, cough headache, cough syncope). A substantial proportion of patients experience anxiety and insomnia, and their quality of life is affected. Thus, the wide spectrum of cough-induced pathology need to be recognized and considered in patients complaining of cough. Suppression of cough must not be neglected in patients at risk, and areas of uncertainty need to be clarified by future prospective studies.

Obesity Predicts Treatment Response to Proton Pump Inhibitor Therapy in Patients with Chronic Cough

BACKGROUND

Chronic cough management is challenging as this condition is often associated with multiple comorbidities, requiring a multidisciplinary diagnostic approach. Little is known about the characteristics of obese patients with chronic cough. This study aims to describe treatable traits of chronic cough and the response to pump proton inhibitor (PPI) therapy in this sub-group of patients.

METHODS

A retrospective, observational study was performed in patients with chronic cough in a French University Hospital. Characteristics of chronic cough were analyzed for obese (N = 112) and non-obese (N = 355) patients. Refractory cough was estimated at 6 and 12 months.

RESULTS

The 3 main treatable traits associated with chronic cough in obese patients and non-obese patients were gastroesophageal reflux disease (GERD), asthma, and upper airway cough syndrome (UACS). A noticeable difference was the higher frequency of GERD (47.3% vs 34.6%, p = 0.0188) and obstructive sleep apnea (OSA) (9.8% vs 3.1%, p = 0.0080) in obese patients compared to non-obese patients. Pump proton inhibitor (PPI) treatment had a significantly higher success rate in obese patients (32.5% vs 17.0%, p < 0.05) and refractory cough at 12 months was less frequently reported in obese patients (22.3% vs 34.1%, p < 0.05).

CONCLUSION

In a context of chronic cough, a higher prevalence of GERD was noted in obese patients compared to non-obese patients and obese patients were more responsive to PPI treatment. Moreover, OSA was reported more frequently as a treatable trait in obese patients and should be considered early in the diagnostic evaluation. Prospective clinical studies that evaluate the contribution of obesity to chronic cough are further needed.