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

Pulmonary manifestations of gastroesophageal reflux disease

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a widespread condition with a significant impact on the quality of life and healthcare resources. In addition to its gastrointestinal problems, GERD has been linked to a variety of respiratory diseases either as a direct cause, or as a risk factor to the inability to control or worsening of the disease.

AREAS COVERED

We performed a literature search in the PubMed database for articles addressing GERD and pulmonary diseases. This review will discuss several different pulmonary diseases affected by GERD ranging from upper airway including chronic cough, vocal cord dysfunction, lower airway diseases including COPD, asthma, and bronchiolitis obliterans syndrome to parenchymal diseases such as interstitial lung diseases. The review will discuss several different pulmonary manifestations of GERD and their contribution to patient mortality and morbidity. It will also review the mechanisms leading to these diseases, diagnostic workup, and the role of the available treatment options.

EXPERT OPINION

GERD is often overlooked as a cause of respiratory symptoms and illnesses. The literature is sparse on the relation between GERD and respiratory diseases such as interstitial lung diseases and bronchiolitis obliterans including its role in pathogenesis, mechanisms of lung injury, and whether treatment of GERD is effective in managing such illnesses.

Chronic cough in Vocal Cord Dysfunction: Description of a clinical entity

BACKGROUND AND AIM

Vocal Cord Dysfunction (VCD) and chronic cough (CC) are challenging conditions which lead to significant quality of life impairment. The underlying mechanisms are poorly understood, but laryngeal dysfunction may be common to both conditions. The aim of this study was to determine the characteristics of cough in VCD and whether patients with cough have coexisting VCD.

METHOD

Participants included 51 patients with VCD and a comparison group of 39 patients with chronic cough that was refractory to medical treatment. Participants underwent a comprehensive assessment including questionnaires, laryngoscopy, cough frequency monitoring and voice testing.

RESULTS

Patients with VCD had significant cough morbidity with an increased cough frequency of 17.3 coughs/hour and reduced cough quality of life with mean Leicester Cough Questionnaire Score of 12.8. Breathing pattern abnormalities were also common in VCD and there was a strong correlation between the number of breathing pattern abnormalities and cough frequency (r = -0.827, p = 0.002). Cough measures were not significantly different between patients with VCD and those with CC. Moderate-severe PVFM was present in 69% of patients with CC. Abnormal vocal fold closure during phonation was also present in patients with chronic cough and was similar between the VCD (n = 40, 78.4%) and cough (n = 25, 64.1%) groups, p = 0.240.

CONCLUSION

Cough is an important symptom in VCD. Patients presenting with chronic cough may have underlying VCD as a cause of their cough. Since cough and VCD symptoms co-occur clinicians need to consider cough when are treating VCD and VCD when treating chronic cough.

Prevalence and incidence of, and risk factors for chronic cough in the adult population: the Rotterdam Study

Chronic cough is a common complaint in the general population but there are no precise data on the incidence of, and prospectively examined risk factors for chronic cough in a population-based setting. Therefore, we investigated the period prevalence, incidence and risk factors for chronic cough in adult subjects. In a prospective population-based cohort study among subjects aged ≥45 years, data on chronic cough were collected on two separate occasions using a standardised questionnaire. Chronic cough was defined as daily coughing for at least 3 months duration during the preceding 2 years. Potential risk factors were gathered by interview, physical examination and several investigations. Of the 9824 participants in this study, 1073 (10.9%) subjects had chronic cough at baseline. The prevalence of chronic cough increased with age and peaked in the eighth decade. In subjects aged <70 years, chronic cough was more common in women. During an average follow-up of 6 years, 439 incident cases of chronic cough occurred with an overall incidence rate of 11.6 per 1000 person-years (95% CI 10.6-12.8). In current smokers, the incidence of chronic cough was higher in men. In the multivariable analysis, current smoking, gastro-oesophageal reflux disease (GORD), asthma and COPD were identified as risk factors for chronic cough. Chronic cough is common among adults and highly prevalent in the older population. Current smoking, GORD, asthma and COPD are independent risk factors for chronic cough. Individuals at risk of developing chronic cough may benefit from smoking cessation and control of the underlying disease.

Association of cough with asthma in chronic rhinosinusitis patients

OBJECTIVE

To determine whether the complaint of cough in chronic rhinosinusitis (CRS) patients is associated with asthma and if there is a potential predictive value for asthma diagnosis.

METHOD

Consecutive patients presenting for initial evaluation at a tertiary rhinology clinic who were diagnosed with CRS were considered for inclusion in a cross-sectional study. The presence and severity of cough was determined using the 22-item Sinonasal Outcome Test (SNOT-22). Subgroup analysis included asthma diagnosis confirmed by pulmonary function testing (PFT) in our institution, and for chronic rhinosinusitis patients with (CRSwNP) and without nasal polyps (CRSsNP).

RESULTS

The total study population included 297 patients with a diagnosis of CRS, with 63.9% of patients reporting cough. Physician-confirmed diagnosis of asthma was made in 38.7% of patients, and confirmed in 69.6% by PFT. Cough was more frequently reported by CRS patients diagnosed with asthma (relative risk [RR] = 1.60, 95% confidence interval [CI], 1.13-2.25), with sensitivity of 73.9% (95% CI, 65.0%-81.1%). This remained significant in the CRSsNP subgroup (RR = 2.65, 95% CI, 1.32-5.30), with sensitivity of 83.3% (95% CI, 70.4%-91.3%) and specificity of 41.2% (95% CI, 33.2%-49.8%). Cough was not associated with asthma in CRSwNP patients (RR = 1.26, 95% CI, 0.89-1.79). Cough severity had poor predication for asthma diagnosis (AUC = 0.60, 95% CI, 0.54-0.65).

CONCLUSIONS

Complaint of cough is associated with diagnosis of asthma in CRS patients. In CRSsNP, complaint of cough was sensitive for asthma diagnosis, although specificity was low. Cough in CRS patients can be multifactorial and asthma may be an important diagnostic consideration.

LEVEL OF EVIDENCE

4.

Burden of Specialist-Diagnosed Chronic Cough in Adults

BACKGROUND

The burden of chronic cough (CC) in patients seeking specialist care is infrequently researched.

OBJECTIVE

To describe patient characteristics and disease burden associated with specialist-diagnosed CC.

METHODS

Using administrative pharmacy and medical data, we identified patients aged 18 to 85 years with CC diagnosed by pulmonologists, allergists, otolaryngologists, or gastroenterologists. Patients were stratified into 4 subgroups on the basis of the presence or absence of common respiratory diseases or gastroesophageal reflux disease (GERD). Clinical features and health care resource utilization (HCRU) in the baseline and outcome years were compared between the CC subgroups. The baseline factors associated with persistence of CC and a comparison of the CC cohort to a matched noncough cohort were also determined.

RESULTS

The 11,290 patients with specialist-diagnosed CC were aged about 61 years and 66.7% were females. The CC cohort experienced frequent GERD (44.1%), asthma (31.2%), obesity (24.3%), upper airway cough syndrome (20.4%), common cough complications (19.4%), and hospitalizations (9.8%). The patients with CC with both respiratory disease and GERD exhibited at baseline and follow-up the most common cough comorbidities, higher HCRU, specialist care, and dispensed respiratory and nonrespiratory medications including proton pump inhibitors, antitussives, psychotherapeutics, oral corticosteroids, and antibiotics compared with the other subgroups. A 40.6% persistence of CC occurred similarly between CC subgroups. In addition, patients with CC in the matched analysis experienced significantly more comorbidities, laboratory evaluations, HCRU, and antitussives than patients without cough.

CONCLUSIONS

Specialist-diagnosed CC was associated with considerable disease burden, particularly among those with both respiratory disease and GERD. In addition, CC burden was more pronounced than in matched patients without cough.

Exploring the clinical relevance of cough hypersensitivity syndrome

Introduction: Knowledge of the pathophysiology of cough has continued to advance over recent decades. Establishing anatomic-diagnostic protocols, based on the anatomy and distribution of vagus nerve pathways regulating the cough reflex, was the first breakthrough in modern clinical medicine for chronic cough. The unmet clinical need has prompted revised thinking regarding the pathophysiology of and the clinical approach to chronic cough.Areas covered: The paradigm of cough hypersensitivity syndrome (CHS) has been recently proposed, wherein aberrant neuro-pathophysiology is a common etiology. This review covers major findings on chronic cough and cough hypersensitivity, particularly focused on recently-published studies and explores the clinical relevance and applicability of CHS based on current knowledge and discuss knowledge gaps and future research directions.Expert opinion: This paradigm has provided new opportunities in managing chronic cough and evidence is accumulating to support the validity of CHS. It also warrants the re-appraisal of existing clinical evidence and investigation of how to refine our clinical strategy. While CHS highlights the importance of clinical thinking from the viewpoint of cough, the value of anatomic-diagnostic protocols should remain. Moreover, given the considerable heterogeneity in clinical presentation, cough-associated disease conditions, and treatment responses across different patients, precise molecular endotyping remains key to making further to advancing clinical practice .

Arnold Nerve Reflex: Vagal Hypersensitivity in Chronic Cough With Various Causes

BACKGROUND

A higher incidence of Arnold nerve reflex (ANR) has been observed in patients with chronic cough. However, the different ANR response in various causes of chronic cough remains unclear. Furthermore, it is unknown whether ANR will change after effective treatment.

METHODS

Patients with chronic cough were enrolled in the Guangzhou Institute of Respiratory Health. The causes of chronic cough were diagnosed via a validated management algorithm. Patients underwent an assessment of ANR response before and after 1 month of etiologic treatment.

RESULTS

A total of 127 patients with chronic cough and 55 healthy control subjects were enrolled. The positive response, defined as cough-only ANR or urge-to-cough (UTC), was present in 14.8% of patients with cough variant asthma (CVA), 11.1% of patients with upper airway cough syndrome, 15.4% of patients with gastroesophageal reflex related cough (GERC), 4.8% of patients with eosinophilic bronchitis, and 26.9% of patients with unexplained cough (UC). No ANR or UTC was found in the healthy control subjects. The incidence of the positive response was higher in subjects with CVA, GERC, and UC compared with healthy control subjects (all P < .05). No difference was observed among the different causes of chronic cough (all P > .05). After 1 month of treatment, 87.5% of patients identified with a positive response changed to a negative response. In a subgroup analysis, an increased cough sensitivity to capsaicin was found in the patients with a positive response compared with the patients with a negative response (P < .05).

CONCLUSIONS

A positive ANR appears to be a sign of vagal hypersensitivity and can be reversed after effective treatment of chronic cough. However, although various causes of chronic cough share a similar feature of an elevated ANR response in a minority of patients, there appears to be limited usefulness in assessing ANR because it does not appear to be a valid predictor of etiology of chronic cough or outcome of treatment.

Current Status and Future Directions of Chronic Cough in China

Chronic cough is one of the most common complaints for which patients in China seek medical attention. However, there are no nationwide data on the prevalence and socioeconomic burden of chronic cough. Although approximately 50% of Chinese men smoke, the vast majority of patients presenting for evaluation of chronic cough are never smokers. An equal sex distribution and a middle-aged predominance have been observed in the Chinese chronic cough population, despite demonstration of a higher cough reflex sensitivity in females and older patients. The role of air pollution in the distinct age and sex distribution requires further study. In terms of the etiologies of chronic cough in China, cough-variant asthma, upper airway cough syndrome, nonasthmatic eosinophilic bronchitis, and atopic cough are the most common causes, comprising 75.2% to 87.6% of cases across different regions. Chinese Guidelines for Diagnosis and Treatment of Cough were initially published in 2005, and updated in 2009 and 2016. In addition, the China Cough Coalition was established in 2016. Great progress has been made in both cough-related clinical practice and research in recent years, however, there are still challenges ahead. To facilitate optimal management of chronic cough in China, efforts promoting the dissemination and application of published guidelines will be essential, especially in community-based healthcare and in rural regions. As chronic refractory cough has been identified as a huge challenge to clinicians worldwide, continued international cooperation will be essential in optimizing evaluation and management of chronic cough.

Cough: A Practical and Multifaceted Approach to Diagnosis and Management

Cough is a common symptom often confronted in the clinical setting. Time and resources attributed to cough place an undue burden on patients and the health care system. One characteristic of cough that likely contributes to this is the multifactorial nature of cough. Physicians are trained to find a single diagnosis to explain symptoms. With cough, if all factors contributing are not identified and treated together, the cough often remains unresolved. This article provides a practical approach to treatment and management of cough, emphasizing causes and potentiators.

Impact of Chronic Cough on Health-Related Quality of Life in the Korean Adult General Population: The Korean National Health and Nutrition Examination Survey 2010-2016

Purpose

Chronic cough is a prevalent condition in the community and may pose considerable impairment to quality of life (QoL). However, its disease burden remains largely undefined in the general population. The present study investigated the relationship between chronic cough and health-related QoL in a Korean nationwide population database, with an emphasis on clinical conditions which may confound the impact of cough.

Methods

This study analyzed cross-sectional datasets of adults (aged ≥ 40 years) in the Korean National Health and Nutrition Examination Survey 2010–2016. Health-related QoL was assessed using the 3-level EuroQoL 5-dimension component (EQ-5D-3L) index score. The presence of chronic cough and other conditions were defined using structured questionnaires.

Results

The prevalence of chronic cough was 3.48% ± 0.17% among adults aged ≥ 40 years. The overall EQ-5D-3L index score was significantly lower in subjects with than without chronic cough (0.79 ± 0.01 vs. 0.86 ± 0.00, P < 0.001). In subgroup analyses by age and sex, chronic cough had a notably large impact on QoL in women aged ≥ 65 years (vs. those without chronic cough: 0.55 ± 0.04 vs. 0.70 ± 0.01, P < 0.001), although the mean difference in the scores exceeded the minimally important difference score of 0.05 in all subgroups. In multivariate analyses, chronic cough was significantly associated with QoL, independent of confounders including depression, arthritis, asthma, and chronic obstructive pulmonary disease. In dimension analyses, chronic cough was more associated with anxiety/depression, pain/discomfort, and usual activities than with self-care or mobility in the EQ-5D.

Conclusions

The present study demonstrated significant associations between chronic cough and health-related QoL in a nationwide large general adult population aged ≥ 40 years, which were independent of clinical confounders. The impact of chronic cough was greater in women aged ≥ 65 years. These findings indicate a considerable burden of chronic cough in the general population and warrant further investigations to assess the disease burden of chronic cough in a global scale.

Bronchoscopy for Chronic Unexplained Cough: Use of Biopsies and Cultures Increase Diagnostic Yield

BACKGROUND

Prior studies assessing the diagnostic utility of bronchoscopy for chronic unexplained cough have focused primarily on identifying endobronchial anomalies to determine chronic cough etiology. On the basis of our institutional experience, expanding bronchoscopy to include cultures and biopsies can considerably increase its diagnostic yield for identifying the etiology of chronic unexplained cough.

MATERIALS AND METHODS

This retrospective review analyzed bronchoscopies conducted in our institution between 2013 and 2017. Eligibility criteria were bronchoscopies conducted for chronic unexplained cough for which no etiology had been identified before the bronchoscopy. Microbiology, pathology, and cytology results from bronchoscopy were reviewed to identify the etiology of the cough.

RESULTS

Over the study period, 169 bronchoscopies met the eligibility criteria. The average patient age at bronchoscopy was 59.7±14.8 years; 61% were female individuals. Direct visualization identified anatomic etiologies in 48 (28%) patients, most commonly tracheobronchomalacia, and less common conditions, such as tracheobronchopathia osteochondroplastica. Microbiology cultures were positive in 33 (20%) patients, principally Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and nontuberculosis mycobacterium. Pathology results from endobronchial biopsies identified respiratory conditions associated with cough, primarily eosinophilic bronchitis (n=15), as well as neurofibromatosis (n=1) and amyloidosis (n=1). Cytology results did not reveal alternate diagnoses not previously identified.

CONCLUSION

Inclusion of bronchial washings and endobronchial biopsies during bronchoscopy for chronic unexplained cough increased diagnostic yield from 28%, attributable to directly visualized anatomic etiologies, to 41%. The addition of microbiology cultures and pathology analysis significantly increased the diagnostic yield of bronchoscopy in identifying the potential etiology of chronic heretofore unexplained cough.

Controversies in Cough Management: An Indian Perspective

Chronic cough is one of the most common symptoms for patients-seeking consultation in an outpatient clinic. It is associated with substantial psychological, physical, and social burdens and impaired quality of life. This review highlights some of the major diagnostic and management challenges confronted in the field of cough with a special focus on the Indian perspective. Heterogeneity in definitions and classifications and challenges associated with over-the-counter drug use and irrational drug use are some of the major controversies. Streamlined diagnostic approach involving a combination of subjective and objective tools, evidence-based amendments in clinical practice, and stringent implementation of regulatory guidelines are mandatory to address controversies in cough management in developing countries.

Bronchiectasis and cough: An old relationship in need of renewed attention

Bronchiectasis is an increasingly recognised respiratory condition with limited therapeutic options and a complex spectrum of clinical manifestations that invariably includes chronic cough. As the primary presentation of bronchiectasis in most cases, chronic cough and its mechanistic underpinnings are of central importance but remain poorly understood in this setting. Bronchiectasis is also increasingly identified as an underlying cause of chronic cough highlighting the interrelationship between the two conditions that share overlapping clinical features. Several therapeutic approaches have illustrated positive effects on bronchiectasis-associated cough, however, more focused treatment of heterogeneous cough subtypes may yield better outcomes for patients. A current challenge is the identification of bronchiectasis and cough endophenotypes that may allow improved patient stratification and more targeted therapeutic matching of the right treatment to the right patient. Here we discuss the complex disease phenotypes of bronchiectasis and their interrelationship with cough while considering current and emerging treatment options. We discuss some key cough promoters in bronchiectasis including infection, allergy and immune dysfunction.

Superior laryngeal nerve block for neurogenic cough: A case series

Objectives

To demonstrate that an in‐office superior laryngeal nerve (SLN) block with lidocaine and steroids is an effective alternative to neuromodulators for patients with neurogenic cough.

Study Design

Retrospective study.

Methods

A retrospective review of 10 patients who underwent in office nerve block to the laryngeal nerve (SLN) for neurogenic cough. Demographic data and pre‐ and postcough survey index are the measure outcomes. Follow‐up was 3–6 months.

Results

We find that all patients in this study that underwent an SLN block showed significant improvement in cough severity index (CSI). The average number of blocks was 2.3. The mean follow‐up time from the first SLN block is 3.4 months. The mean CSI improvement 16.30. 95% confidence interval, 11.44–21.16; P < .0001. All patients in this study completed at least one session of cough suppression therapy with speech language pathology (SLP). No patients were on neuromodulators at the time of the SLN block.

Conclusions

There is a role for in‐office SLN block with lidocaine and steroids for patients with neurogenic cough, and can be an effective alternative to neuromodulators.

Level of Evidence

NA

Risk factors for repetitive doctor's consultations due to cough: a cross-sectional study in a Finnish employed population

OBJECTIVES

Cough is the most common symptom prompting people to consult a doctor, thus representing a huge cost to the healthcare. This burden could be reduced by decreasing the number of repetitive consultations by the same individuals. Therefore, it would be valuable to recognise the factors that associate with repetitive doctor's consultations due to cough.

DESIGN

A cross-sectional, email survey.

SETTING

Public service employees in two Finnish towns.

PARTICIPANTS

The questionnaire was sent to 13 980 subjects; 3695 (26.4 %) participated.

INTERVENTIONS

The questionnaire sought detailed information about participant characteristics, all disorders diagnosed by a doctor, various symptoms and doctor's consultations. Those with current cough were inquired about cough characteristics and filled in the Leicester Cough Questionnaire (LCQ).

PRIMARY OUTCOME

Repetitive (≥3) doctor's consultations due to cough during the previous 12 months.

RESULTS

There were 205 participants (5.5% of the participants) with repetitive consultations. They accounted for 848 out of the 1681 doctor's consultations (50.4%) due to cough. Among all participants, repetitive consultations were mainly related to the presence of asthma (adjusted OR (aOR) 2.90 (2.01 to 4.19)) and chronic rhinosinusitis (aOR 2.40 (1.74 to 3.32)). Among the 975 participants with current cough, repetitive consultations were mainly related to a low LCQ total score (aOR 3.84 (2.76 to 5.34) per tertile). Comorbidity, depressive symptoms and smoking were also associated with repetitive consultations.

CONCLUSIONS

A modest proportion of subjects with repetitive consultations is responsible for every second doctor's consultation due to cough. The typical features of these subjects could be identified. These findings can help to focus on certain subpopulations in order to plan interventions to reduce the healthcare burden attributable to cough.

Characteristics of Chinese chronic cough patients

Chronic cough is one of the most common complains for patients seeking medical attention in both general practice and respiratory specialist clinics. Cough variant asthma, eosinophilic bronchitis, upper airway cough syndrome, as well as gastro-esophageal reflux disease are common conditions associated with chronic cough, and cough variant asthma, eosinophilic bronchitis account for a higher proportion of patients with chronic cough in China than in Western countries. An older female predominance has been reported in most Western countries, which may be attributed to a higher cough reflex sensitivity in females, especially those post-menopausal females. However, studies conducted in China showed that patients with chronic cough have a nearly similar gender distribution and most of them are in their late 30s or early 40s, despite the similar gender and age difference in cough reflex sensitivity as Western countries. Environmental and occupational exposures, cigarette smoking, unhealthy lifestyle might play a role in the distinct age and gender distribution of Chinese chronic cough patients, yet further study is needed to clarify it.

Subfreezing air as a cough trigger and multiple triggers are strongly associated with the presence of asthma in chronic cough

BACKGROUND

Management of chronic cough relies on the recognition of cough background disorders. It is not known whether certain cough triggers are associated with specific background disorders.

METHODS

This was an e-mail study to public service employees of two towns in Finland. The questionnaire included twelve triggers. Current asthma was defined as doctor's diagnosis of asthma and current wheezing. Chronic rhinosinusitis was defined as either nasal blockage or nasal discharge and either facial pain/pressure or reduction/loss of smell for more than three months. Gastroesophageal reflux disease was defined as heartburn and/or regurgitation on at least one day a week during the last three months. Idiopathic cough was defined as absence of any of them.

RESULTS

There were 421 subjects with current cough that had lasted at least eight weeks. Subfreezing air as a cough trigger was associated with an adjusted odds ratio (aOR) of 7.27 (4.09-12.9), (p < 0.001), for current asthma. The number of cough triggers was largest in asthma, followed by chronic rhinosinusitis, gastroesophageal reflux, and idiopathic cough (7.05 (6.14-7.96), 4.94 (4.35-5.54), 4.60 (3.77-5.43), and 3.44 (3.02-3.86), respectively, p < 0.001). Presence of five or more triggers was associated with an aOR of 7.49 (3.96-14.2), (p < 0.001) for current asthma. Absence of any cough triggers increased the probability of idiopathic cough (aOR 2.71 (1.54-4.77), p = 0.001).

CONCLUSIONS

Subfreezing air as a cough trigger and multiple triggers are strongly associated with the presence of current asthma in chronic cough. Absence of any cough triggers increases the probability of idiopathic cough.

The Spectrum of Non-asthmatic Airway Diseases Contributing to Cough in the Adult

PURPOSE OF REVIEW

Cough becomes a pathologic reflex when the airways are inflamed and overwhelmed with excessive mucus. The goal of this review is to discuss acute and chronic cough syndromes caused by non-asthmatic airway diseases.

RECENT FINDINGS

Acute cough syndrome is short-lived and self-limited. Acute bronchitis and diffuse acute infectious bronchiolitis (DAIB) are examples. The former is usually caused by a viral illness; the latter by Mycoplasma pneumoniae, influenza, and Haemophilus influenzae. Causes of chronic cough in the adult include chronic bronchitis, non-infectious bronchiolitis, and non-cystic fibrosis bronchiectasis.

SUMMARY

Supportive measures are recommended for acute bronchitis and antibiotic use is discouraged. Antibiotics may be needed for DAIB. Smoking cessation and bronchodilators can control cough in chronic bronchitis. Therapeutic approaches for non-infectious bronchiolitis depend on the varied etiology. The hallmark of bronchiectasis is a chronic infection of the airways, and antibiotics, mucus clearance measures, and bronchodilators are all supportive.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

Predictors of prolongation in recent-onset cough

Chronic cough greatly decreases the quality of life and is often refractory to treatment. Interventions at an early stage could prevent cough from becoming chronic. To this end, the patients at high risk of cough prolongation would need to be identified. In this study, we investigated the factors that predicted cough at 12 months among subjects with a recent-onset cough. This was a prospective, observational follow-up study in a community-based population consisting of working-age subjects. The first e-mail survey in 2017 included a comprehensive questionnaire about current cough and its risk factors. The 259 subjects who reported a recent-onset (<8 weeks) cough were sent a follow-up questionnaire 12 months later. The response rate was 72.6% (188 subjects). There were 99 subjects (52.7%) with cough in 2018. The following baseline factors predicted the presence of any cough at 12 months in the multivariable analysis: wheezing (adjusted odds ratio (aOR 2.80, 95% CI 1.3-5.27), dog ownership (aOR 2.56, 95% CI 1.21-5.44), cough duration >3 weeks (aOR 2.29, 95% CI 1.11-4.76), family history of chronic cough (aOR 2.20, 95% CI 1.13-4.30), body mass index >25 kg·m-2 (aOR 2.06, 95% CI 1.02-4.15) and frequent somatic symptoms (aOR 1.36, 95% CI 1.13--1.64). There were 29 subjects (15.4%) with continuous cough and 66 subjects (35.1%) with recurrent cough. The risk factors were completely different between recurrent and continuous cough. It may be possible to identify the risk factors of cough prolongation among subjects with recent-onset cough. Early interventions should be targeted to these kinds of patients.

[From acute cough to chronic cough in adults: Overview on a common reason for consultation]

Cough is divided into two categories: acute cough lasting less than 3 weeks, and chronic cough lasting more than 8 weeks. Acute cough is usually triggered by a viral infection of the upper airways. Evidence of treatment effectiveness is low and management of acute cough is complex in clinical practice. Chronic cough is a common reason for consultation in medicine. The most frequent causes are upper airway diseases, gastroesophageal reflux disease, asthma, eosinophilic bronchitis, and drugs. Before investigation, smoking cessation and drug withdrawal must be achieved for 4 to 6 weeks. Once this step is completed, simple investigations have to be performed in order to find common causes of chronic cough (questioning, physical examination, spirometry, chest X-ray). If no causes have been identified or cough remains despite optimal treatment, exhaustive exploration has to be performed to rule out rare causes. A chronic cough hypersensitivity syndrome is suggested if any causes have been found despite exhaustive assessment or if cough remains with optimal treatments. This syndrome is characterized by an increase in the sensitivity of cough peripheral receptors and is not sensitive to usual therapies. The therapeutic options are limited but innovative treatments such as P2X3 receptor antagonists are in development.

Update on the clinical development of gefapixant, a P2X3 receptor antagonist for the treatment of refractory chronic cough

Chronic cough, or cough lasting >8 weeks, is often associated with underlying medical conditions (ie, asthma, gastroesophageal reflux disease, nonasthmatic eosinophilic bronchitis, and upper-airway cough syndrome). In some patients with chronic cough, treatment of these underlying conditions does not resolve the cough (refractory chronic cough [RCC]), or none of these conditions are present (unexplained chronic cough [UCC]). Despite appropriate medical evaluation, patients with RCC or UCC frequently experience cough persisting for many years, as there are currently no targeted pharmacological approaches approved for the treatment of these conditions. However, the adenosine triphosphate (ATP)-gated P2X3 receptor, a key modulator of the activation of sensory neurons central to the cough reflex, has recently garnered attention as a potential therapeutic target for the treatment of chronic cough. Gefapixant, a first-in-class, non-narcotic, selective antagonist of the P2X3 receptor, recently demonstrated efficacy and was generally well tolerated in phase 2 clinical trials in patients with RCC, validating the utility of targeting this receptor in patients with chronic cough. On the basis of these data, 2 global phase 3 trials, with combined anticipated enrolment exceeding 2000 patients and with treatment durations of up to 1 year, have been initiated. Together, these trials will further evaluate efficacy and safety of gefapixant in the control of cough in patients with RCC or UCC.

Chronic Cough in Adults: Make the Diagnosis and Make a Difference

Chronic cough is common and impactful, frustrating both patients and clinicians. An empirical trial of therapy is often done with inhaled corticosteroids, but this practice should be replaced with attempting to make an accurate diagnosis. The three most common causes are upper airway cough syndrome, asthma, and gastroesophageal reflux disease (GERD), but there are often multiple causes involved. Minimal investigations after history, physical exam, travel history, and drug history include a chest radiograph and spirometry. Empirical trial of therapy with inhaled corticosteroids is reasonable if there is evidence of eosinophilic inflammation. Empiric therapy for GERD may also be reasonable in those with symptoms. Red flags should especially be considered an urgency to make the correct diagnosis.

Chronic cough and obesity

With respective prevalence of 13% and 9.6%, obesity and chronic cough are two common conditions worldwide. The crucial role of obesity has been highlighted in the development and progression of many respiratory diseases. According to the results of epidemiological studies, obesity, particularly abdominal obesity, may also be associated with chronic cough (CC). CC seems to be more severe in obese patients compared to normal-weight subjects. The management of CC may differ slightly in obese patients compared to non-obese patients. Indeed, asthma and reflux diseases, which are considered key factors in the onset of CC, are characterised by more severe symptoms in obese patients. Asthma is associated with a resistance to usual treatments in obese patients but no data are available on the effect of inhaled therapies in obese subjects with cough variant asthma. Other emergent causes of CC have been reported in obese patients. Obstructive sleep apnoea and diabetes may also be involved in the development of CC and should be taken into account in obese patients with CC. The beneficial effect of weight loss on chronic cough has been suggested.

Cough in exercise and athletes

In the general population, particularly in individuals with asthma, cough is a common symptom, often reported after exertion, although regular exercise may be associated with a reduction in the prevalence of cough. In athletes, exercise-induced cough is also a particularly frequent symptom. The main etiologies of cough in athletes are somewhat similar to non-athletes, including asthma/airway hyperresponsiveness, upper airways disorders such as allergic or non-allergic rhinitis, and exercise-induced laryngeal obstruction, although these conditions are more frequently observed in athletes. In these last, this symptom can also be related to the high ventilation and heat exchange experienced during exercise, particularly during exposure to cold/dry air or pollutants. However, gastroesophageal reflux, a common cause of cough in the general population, despite being highly prevalent in athletes, has not been reported as a main cause of cough in athletes. Cough may impair quality of life, sleep and exercise performance in the general population and probably also in athletes, although there are few data on this. The causes of cough should be documented through a systematic evaluation, the treatment adapted according to identified or most probable cough etiology and pattern of presentation, while respecting sports anti-doping regulations. More research is needed on exercise-induced persistent cough in the athlete to determine its pathophysiology, optimal management and consequences.

Value of Exhaled Nitric Oxide and FEF25-75 in Identifying Factors Associated With Chronic Cough in Allergic Rhinitis

Purpose

Chronic cough in allergic rhinitis (AR) patients is common with multiple etiologies including cough variant asthma (CVA), non-asthmatic eosinophilic bronchitis (NAEB), gastroesophageal reflux-related cough (GERC), and upper airway cough syndrome (UACS). Practical indicators that distinguish these categories are lacking. We aimed to explore the diagnostic value of the fraction of exhaled nitric oxide (FeNO) and forced expiratory flow at 25% and 75% of pulmonary volume (FEF_25–75) in specifically identifying CVA and NAEB in these patients.

Methods

Consecutive AR patients with chronic cough were screened and underwent induced sputum, FeNO, nasal nitric oxide, spirometry, and methacholine bronchial provocation testing. All patients also completed gastroesophageal reflux disease questionnaires.

Results

Among 1,680 AR patients, 324 (19.3%) were identified with chronic cough, of whom 316 (97.5%) underwent etiology analyses. Overall, 87 (27.5%) patients had chronic cough caused by NAEB, 78 (24.7%) by CVA, 16 (5.1%) by GERC, and 81 (25.6%) by UACS. Patients with either NAEB or CVA (n = 165, in total) were further assigned to a common group designated as CVA/NAEB, because they both responded to corticosteroid therapy. Receiver operating characteristic curves of FeNO revealed obvious differences among CVA, NAEB, and CVA/NAEB (area under the curve = 0.855, 0.699, and 0.923, respectively). The cutoff values of FeNO at 43.5 and 32.5 ppb were shown to best differentiate CVA and CVA/NAEB, respectively. FEF_25–75 was significantly lower in patients with CVA than in those with other causes. A FEF_25–75 value of 74.6% showed good sensitivity and specificity for identifying patients with CVA.

Conclusions

NAEB, CVA, and UACS are common causes of chronic cough in patients with AR. FeNO can first be used to discriminate patients with CVA/NAEB, then FEF_25–75 (or combined with FeNO) can further discriminate patients with CVA from those with CVA/NAEB.

Cough

Pharmacists play an important role in the assessment and management of patients with cough. By obtaining a focused clinical history from the patient, they can identify patients who need to be referred to their physician or to the emergency room, as well as which patients can be managed at home. Red flags that prompt referral include severe systemic illness, respiratory distress, hemoptysis, and altered level of consciousness. Patients with underlying chronic illnesses such as chronic obstructive pulmonary disease, asthma, and heart failure who present with cough should be assessed for possible exacerbation of their illness and should be referred if this is suspected. Determining the duration of cough is an important step, as this helps identify possible etiologies. Cough <3-week duration is categorized as acute, 3- to 8-week duration is subacute, and > 8-week duration is a chronic cough. Patients with cough lasting >3 weeks should generally be referred for further evaluation and management. Acute cough is often infectious but can also be due to exacerbation of underlying illness or could be medication-related. Upper airway cough syndrome (UACS) is one of the most common causes of subacute and chronic cough. Several different etiologies lead to UACS, which is thought to be caused by postnasal drip ± sensitization of cough receptors in the respiratory tract. First-generation antihistamines or decongestants are therapeutic options when UACS is suspected. It is important to note that antitussive medications such as dextromethorphan can actually prolong illness in patients with a productive cough and are thus not recommended. Monitoring parameters and frequency of follow-up depend on underlying cause, severity of illnesses, past medical history, as well as medication changes.

Inhaled Corticosteroids and Placebo Treatment Effects in Adult Patients With Cough: A Systematic Review and Meta-analysis

PURPOSE

Inhaled corticosteroids (ICSs) are often considered an empirical therapy in the management of patients with cough. However, ICS responsiveness is difficult to interpret in daily clinical practice, as the improvements may include placebo effects or self-remission. We aimed to evaluate ICS and placebo treatment effects in adult patients with cough.

METHODS

Electronic databases were searched for studies published until June 2018, without language restriction. Randomized controlled trials reporting the effects of ICSs compared with placebo in adult patients with cough were included. Random effects meta-analyses were conducted to estimate the treatment effects. Therapeutic gain was calculated by subtracting the percentage change from baseline in the cough score in the ICS treatment group from that in the placebo treatment group.

RESULTS

A total of 9 studies were identified and 8 studies measuring cough severity outcomes were included for meta-analyses. Therapeutic gain from ICSs ranged from -5.0% to +94.6% across the studies included; however, it did not exceed +22%, except for an outlier reporting very high therapeutic gains (+45.6% to +94.6%, depending on outcomes). Overall ICS treatment effects in cough severity outcomes were small-to-moderate (standardized mean difference [SMD], -0.38; 95% confidence interval [CI], -0.54, -0.23), which were comparable between subacute and chronic coughs. However, pooled placebo treatment effects were very large in subacute cough (SMD, -2.58; 95% CI, -3.03, -2.1), and modest but significant in chronic cough (SMD, -0.46; 95% CI, -0.72, -0.21).

CONCLUSIONS

Overall therapeutic gain from ICSs is small-to-moderate. However, placebo treatment effects of ICS are large in subacute cough, and modest but still significant in chronic cough. These findings indicate the need for careful interpretation of ICS responsiveness in the management of cough patients in the clinic, and also for rigorous patient selection to identify ICS-responders.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

Managing patients with chronic cough: challenges and solutions

Chronic cough is a common complaint and a frequent cause of medical consultation. Its management can be difficult. We present here an overview of the current guidelines for the management of chronic cough. Different steps are detailed, including the initial research of an obvious etiology and alert signs that should lead to further investigation of underlying condition. The diagnosis of the most frequent causes: asthma, non-asthmatic eosinophilic bronchitis, gastroesophageal reflux disease and upper airway cough syndrome should be considered, assessed and treated accordingly. Recent advances have been made in the comprehension of refractory chronic cough pathophysiology as well as its pharmacologic and non-pharmacologic treatment, especially speech pathology therapy.

Rabeprazole combined with trimebutine for treatment of patients with gastroesophageal reflux cough: Clinical efficacy and impact on serum levels of motilin and gastrin

AIM

To investigate the clinical effect of rabeprazole combined with trimebutine in the treatment of patients with gastroesophageal reflux cough and the impact on serum levels of motilin (MOT) and gastrin (GAS).

METHODS

Ninety-two patients with gastroesophageal reflux cough treated at our hospital from December 2015 to September 2017 were randomly divided into either a control group or a study group. Both groups were treated treated with routine treatment and rabeprazole, and the study group was additionally treated with trimebutine. The total effective rate, cough symptom score, gastroesophageal reflux disease questionnaire (GERDQ) score, and adverse effects were compared between the two groups.

RESULTS

The total effective rate was significantly higher in the study group than in the control group (95.7% vs 80.4%, P < 0.05). Before treatment, there was no significant difference in either day cough symptom score (4.14 ± 0.76 vs 4.28 ± 0.69) or night cough symptom score (4.11 ± 0.81 vs 4.07 ± 0.72) between the study group and the control group (P > 0.05). After treatment, both day cough symptom score and night cough symptom score were significantly lower in the study group than in the control group (P < 0.05). Before treatment, there was no significant difference in GERDQ score between the study group and control group (15.74 ± 3.26 vs 15.81 ± 3.32, P > 0.05). After treatment, the GERDQ score was significantly lower in the study group than in the control group (P < 0.05). Before treatment, serum levels of MOT and GAS did not differ significantly between the two groups (P > 0.05). After treatment, serum levels of MOT and GAS were significantly higher in the study group than in the control group (P < 0.05). There were no adverse effects in either group.

CONCLUSION

Rabeprazole combined with trimebutine can effectively improve clinical symptoms in patients with gastroesophageal reflux cough, without adverse effects.