Springer Science and Business Media LLC

The pathogenesis of chronic cough is not well understood and treatment options are limited. In this study we sought to explore the current understanding and management of chronic cough across an international group of specialists. This was an international study of cross sectional qualitative design. In depth interviews were carried out with “Respiratory Specialists” experienced in treating treating Chronic Obstructive Pulmonary Disease (COPD), idiopathic pulmonary fibrosis (IPF), idiopathic chronic cough (ICC) and/or lung cancer patients and with “Disease Experts” in the field of Chronic Cough. Participants in the study were recruited from the USA, UK, Germany, Ireland, Australia and Japan. Interviews with specialists were held at research facilities and with DEs over the telephone. These were preceded by the specialists completing case records of patients recently seen. All interviews were conducted by native speaking trained moderators using a semi-structured interview guide script. This was designed to elicit the definition of chronic cough, explore the unmet needs for each disease state, define therapy goals, identify patient phenotypes and give an overview of the treatment pathway. 76 specialists and 10 experts took part in the study. Over two thirds (70%) of respondents defined chronic cough as “cough lasting more than 8/12 weeks” (range 2 weeks to 2 years). Physicians emphasised three interdependent aspects of clinical assessment: impact on quality of life, type of cough (productive versus non-productive) and the underlying pathology. Specialists emphasised treating the underlying cause rather than the cough, this being most prominent in Japan. Experts as a group focussed on chronic cough independently. Evaluation of the respiratory system, GI tract and upper airway (ENT) for establishing an underlying cause was recommended. Type of cough (productive vs non-productive) and impact on quality of life influenced treatment initiation. 33% of patients with ICC were prescribed anti-tussives. With associated diagnoses of COPD, IPF or lung cancer the emphasis was on treating the underlying condition. Alternatives to pharmacological treatments were frequently considered. There is significant international variation in our understanding and management of chronic cough. Further work is required to bring forth clear guidance and effective medicines for these patients.

Childhood habit cough has been treated successfully by making suggestions that it can be stopped, desensitization techniques, use of distractors, provision of rewards, and self-hypnosis. All of these techniques have involved personal contact between a health care provider and a patient. A 5-year-old with cystic fibrosis was diagnosed with habit cough following evaluation by a pediatric pulmonologist and otolaryngologist. An expert in the treatment of habit cough provided instruction by telephone to the patient's mother regarding use of hypnotic techniques in this setting, which was associated with resolution of the cough within a week. As this report describes a single patient, it is possible that his improvement was unrelated to the given advice. Therefore, it remains to be seen whether therapy by telephone for habit cough is applicable widely.

Chronic cough patients are rendered therapies for gastro-esophageal reflux (GERD), upper airway cough syndrome (UACS) and cough-variant asthma (CVA) with varying benefit. Idiopathic or unexplained cough has emerged as an important clinical entity in both primary care and subspecialty clinics. Recent evidence points to a link between chronic cough and untreated obstructive sleep apnea (OSA). A prospective observational study was done to evaluate the effect of OSA therapy in patients with chronic cough. Patients enrolled into the study underwent questionnaires to evaluate for GERD, UACS and CVA along with screening questionnaires for OSA and daytime sleepiness. The Leicester cough questionnaire (LCQ) was done at baseline and during serial visits to evaluate cough intensity and was used as the primary outcome measure of the effect of CPAP therapy on chronic cough. Out of 37 patients enrolled into the study, only 28 patients had follow up LCQ scores available and therefore underwent analysis. 22/28 patients were suspected to have OSA based on abnormal STOP-BANG screening questionnaire scores and overnight oximetry abnormalities. Of these 19/28 patients had overnight attended polysomnography with definitive diagnosis of OSA yielding a 68% prevalence of OSA in our chronic cough population. Chronic cough patients treated for OSA tended to be older with a significantly higher BMI than chronic cough patients without OSA. Significant improvement of LCQ scores occurred with CPAP therapy for OSA in chronic cough patients. OSA is significantly prevalent in chronic cough patients. Subjects with chronic cough and OSA tend to be older and obese. Treatment of OSA in chronic cough patients yields significant improvement in their health status.

Cough is one of the most frequent symptoms in children and is the most common symptom for which children visit a health care provider. This is an observational study on acute cough associated with upper respiratory tract infection (URTI) in children. The study evaluates the epidemiology and impact of cough on quality of sleep and children's activities, and the outcome of cough with antitussive treatments in pediatric routine clinical practice. Study assessments were performed through a pediatric cough questionnaire (PCQ), developed by the Italian Society of Cough Study. A total of 433 children visited by family care pediatricians for acute cough due to a URTI were enrolled in this study, with mean age of 6.1 years (SD 3.6). Cough type, duration, severity and frequency, cough impact on sleep disturbances of children and parents and on school and sport activities were assessed at baseline. In a subset of 241 children who were either treated with antitussive drugs (levodropropizine n = 101, central antitussives n = 60) or received no treatment (n = 80), the outcome of cough after 6 days was analyzed in terms of resolution, improvement, no change, or worsening. Descriptive analysis, χ2 test, and multivariate analysis with stepwise logistic regression were performed. Cough disturbed sleep in 88% of children and 72% of parents. In children treated with cough suppressants, the duration, type, intensity, and frequency cough were similar at baseline in the two groups respectively treated with levodropropizine and central antitussives (cloperastine and codeine). Both levodropropizine and central drugs reduced cough intensity and frequency. However, percentage of cough resolution was higher with levodropropizine than with central antitussives (47% vs. 28% respectively, p = 0.0012). Acute cough disturbs sleep in most children and their parents. Both levodropropizine and central antitussives reduced cough intensity, with levodropropizine producing a higher cough resolution rate.

In order to assess severity of cough from patients' perspectives and capture the effects of treatment in clinical trials, a measurement tool must show evidence of validity and reliability. The purpose of this study was to characterize cough severity from patients' perspectives as the initial step in the development of a new patient-reported outcome (PRO) measure for use in clinical trials. This focus groups study included patients with clinician confirmed chronic cough recruited from a large internal medicine clinic in the US. A semi-structured focus group guide was designed to elicit information about patients' experiences with cough severity and their characterization of symptoms. The focus group data were coded to identify concepts and terminology of cough severity. Three focus groups were conducted [n = 22; 6 male; mean age 66.1 (± 12.9)]. Etiology included GERD, asthma, bronchitis, post-nasal drip, and other. Three domains of cough severity were identified: frequency, intensity, and disruption. In addition to a single cough, participants in all focus groups described coughing in uncontrollable paroxysms they called "fits," "bouts," "spells," or "episodes." The urge to cough, described as an important sign of impending cough, was considered a component of cough frequency. Participants also described daytime activity and nighttime sleep disruption as an indication of cough severity. Finally, participants described variability in cough severity. Results suggest that patients describe cough severity in terms of frequency, intensity, and disruptiveness, indicating these 3 domains should be addressed when evaluating cough severity and outcomes of treatment.

A case of tracheobronchopathia osteochondroplastic (TPO) was diagnosed in a 69-year old male with prolonged cough. TPO is a rare condition of unknown cause and only sporadic cases have been reported. The condition is benign, characterized by submucosal nodules growing from the submucosal layer of the airways, protruding into the bronchial lumen. The bronchscopic view together with bronchial cartilage with abnormal distributed mineralization of the histologic examination of theses nodules leads to the correct diagnosis. Mild cases are treated symptomatically, whereas we tried an inhaled corticosteroid. Prominent protrusions in the trachea or the bronchi must be removed. In most cases the disease is stable over years but progressive forms have been reported. TPO may cause chronic refractory cough, which eventually is the only prominent symptom of this disease.

Gastro-oesophageal reflux disease is generally considered to be one of the commonest causes of chronic cough, however randomised controlled trials of proton pump inhibitors have often failed to support this notion. This article reviews the most recent studies investigating the mechanisms thought to link reflux and cough, namely laryngo-pharyngeal reflux, micro-aspiration and neuronal cross-organ sensitisation. How recent evidence might shed light on the failure of acid suppressing therapies and suggest new approaches to treating reflux related cough are also discussed.

Chronic persistent cough can be associated with laryngeal dysfunction that leads to symptoms such as dysphonia, sensory hyperresponsiveness to capsaicin, and motor dysfunction with paradoxical vocal fold movement and variable extrathoracic airflow obstruction (reduced inspiratory airflow). Successful therapy of chronic persistent cough improves symptoms and sensory hyperresponsiveness. The effects of treatment for chronic cough on laryngeal dysfunction are not known. The aim of this study was to investigate effects of therapy for chronic cough and paradoxical vocal fold movement. Adults with chronic cough (n = 24) were assessed before and after treatment for chronic persistent cough by measuring quality of life, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity and fibreoptic laryngoscopy to observe paradoxical vocal fold movement. Subjects with chronic cough were classified into those with (n = 14) or without (n = 10) paradoxical vocal fold movement based on direct observation at laryngoscopy. Following treatment there was a significant improvement in cough related quality of life and cough reflex sensitivity in both groups. Subjects with chronic cough and paradoxical vocal fold movement also had additional improvements in extrathoracic airway hyperresponsiveness and paradoxical vocal fold movement. The degree of improvement in cough reflex sensitivity correlated with the improvement in extrathoracic airway hyperresponsiveness. Laryngeal dysfunction is common in chronic persistent cough, where it is manifest as paradoxical vocal fold movement and extrathoracic airway hyperresponsiveness. Successful treatment for chronic persistent cough leads to improvements in these features of laryngeal dysfunction.

Preparation of inhaled capsaicin solutions for cough induction varies greatly from one lab to another, which creates inconsistencies between tussigenic challenge results. The addition of Tween to these capsaicin solutions provides increased solubility and stability; however, the foul taste of Tween makes inhaling the solution for any prolonged period of time unpleasant. We sought to create a standard method for preparing soluble and stable capsaicin-based solutions (in 10% ethanol/water), without the addition of Tween. Capsaicin solutions were created at concentrations ranging from 0 to 500 μM in a variety of solvent systems, with and without Tween. Samples were stored in four different environments (-20°C, 3°C, and room temperature, protected from light; and room temperature, exposed to light) to test stability. Detection of capsaicin was carried out by UV absorption. A Grubb’s test was performed on all data to remove statistical outliers. Similar capsaicin concentrations were seen for solutions prepared with or without Tween (Tween provided a slight increase in solubility), with neither solvent system providing complete solubility. Of the four environments tested, storing capsaicin solutions at 3°C while protected from light afforded the greatest stability, for a minimum of 30 weeks. We recommend the use of a 10% ethanol/water solvent system without Tween in the preparation of capsaicin solutions for tussigenic challenges. While this solvent system does not provide complete solubility, we have detailed a method for capsaicin solution preparation that will account for this loss of solubility, while maintaining a solution that is Tween-free and safe for human inhalation.

Abstract There has been a rapidly increasing volume of research undertaken in the field of acute and chronic cough at both basic scientific and clinical levels. However, until now there has been no journal dedicated to publishing work in this field. In this editorial, we introduce the new online, open-access journal entitled Cough which has been founded specifically for this purpose. We also review the clinical problems posed by acute and chronic cough and highlight some of the current issues that are being tackled by cough researchers.