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Introduction: The primary self-assessment questionnaire used for patients with chronic cough is the Leicester Cough Questionnaire (LCQ). The LCQ is a validated questionnaire that ranges in total score from 3 to 21. While it is known that a higher score on the LCQ reflects a better quality of life, normative data have not been reported for this questionnaire. Objective: The purpose of this study was to determine normative LCQ scores on a healthy population without cough. Methods: The LCQ was distributed via electronic survey to the authors' universities, professional affiliation email lists, and personal contacts. Participants were included if they were at least 18, nonsmokers, and without abnormal cough, without pulmonary disease, and without neurological disease. Participants answered questions regarding age, gender, and race/ethnicity, and completed the 19 LCQ questions. Results: One hundred forty-three (118 women) LCQ responses were analyzed. Average participant age was 47 years (SD = 13) and 133 (93%) were Caucasian. The mean LCQ Total score was 20.23 (SD = 0.85) with scores ranging from 17.05 to 21. Conclusions: This study determined the following LCQ scores should be considered normal threshold scores: Total score – 17.68, Physical domain – 5.36, Psychological domain – 5.81, and Social domain – 6.06. The findings of this study will assist clinicians in determining severity of cough impact on quality of life using the LCQ. Further research is needed to ensure more complete participant demographic representation. [ABSTRACT FROM AUTHOR]

Background: Chronic cough, i.e., cough lasting longer than eight weeks, affects approximately 10% of the population and is a common reason for outpatient medical consultation. Its differential diagnosis is extensive, and it is generally evaluated in poorly structured fashion with a variety of diagnostic techniques. The German Clinical Practice Guideline on Acute and Chronic Cough was updated in 2021 and contains a description of the recommended stepwise, patient-centered, and evidencebased procedure for the management of chronic cough. Methods: The guideline has been updated in accordance with the findings of a systematic search of the literature for international guidelines and systematic reviews. All recommendations were developed in an interdisciplinary manner and agreed upon by formal consensus. The target group consists of adult patients with cough. Results: History-taking, after the exclusion of red flags, should include questioning about smoking status, medications, and relevant present and past illnesses (COPD, asthma). Subsequent diagnostic testing should include a chest x-ray and pulmonary function tests. If the patient is taking an ACE inhibitor, a test of drug discontinuation can be carried out first. Radiologically detected pulmonary masses or evidence of rare diseases (interstitial lung diseases, bronchiectasis) are an indication for chest CT or for direct referral to an appropriate specialist. If the imaging studies and pulmonary function tests are normal, the patient is most likely suffering from a disease entity that can be treated empirically, such as upper airway cough syndrome or cough variant asthma. Any patient with an unexplained or refractory cough must receive proper patient education; individual therapeutic trials of physiotherapeutic or speech-therapeutic methods are possible, as is the off-label use of gabapentin or morphine. [ABSTRACT FROM AUTHOR]

Background: Chronic cough (CC) of 8 weeks or more affects about 10% of adults and may lead to expensive treatments and reduced quality of life. Incomplete diagnostic coding complicates identifying CC in electronic health records (EHRs). Natural language processing (NLP) of EHR text could improve detection.Research Question: Can NLP be used to identify cough in EHRs, and to characterize adults and encounters with CC?Study Design and Methods: A Midwestern EHR system identified patients aged 18 to 85 years during 2005 to 2015. NLP was used to evaluate text notes, except prescriptions and instructions, for mentions of cough. Two physicians and a biostatistician reviewed 12 sets of 50 encounters each, with iterative refinements, until the positive predictive value for cough encounters exceeded 90%. NLP, International Classification of Diseases, 10th revision, or medication was used to identify cough. Three encounters spanning 56 to 120 days defined CC. Descriptive statistics summarized patients and encounters, including referrals.Results: Optimizing NLP required identifying and eliminating cough denials, instructions, and historical references. Of 235,457 cough encounters, 23% had a relevant diagnostic code or medication. Applying chronicity to cough encounters identified 23,371 patients (61% women) with CC. NLP alone identified 74% of these patients; diagnoses or medications alone identified 15%. The positive predictive value of NLP in the reviewed sample was 97%. Referrals for cough occurred for 3.0% of patients; pulmonary medicine was most common initially (64% of referrals).Limitations: Some patients with diagnosis codes for cough, encounters at intervals greater than 4 months, or multiple acute cough episodes may have been misclassified.Interpretation: NLP successfully identified a large cohort with CC. Most patients were identified through NLP alone, rather than diagnoses or medications. NLP improved detection of patients nearly sevenfold, addressing the gap in ability to identify and characterize CC disease burden. Nearly all cases appeared to be managed in primary care. Identifying these patients is important for characterizing treatment and unmet needs. [ABSTRACT FROM AUTHOR]

Rationale: Chronic cough is characterized by frequent urges to cough and a heightened sensitivity to inhaled irritants. Airway sensory nerves trigger cough. We hypothesized that sensory nerve density is increased in chronic cough, which may contribute to excessive and persistent coughing.Objectives: To measure airway nerve density (axonal length) and complexity (nerve branching, neuropeptide expression) in humans with and without chronic cough.Methods: Bronchoscopic human airway biopsies were immunolabeled for nerves and the sensory neuropeptide substance P. Eosinophil peroxidase was also quantified given previous reports showing associations between eosinophils and nerve density. Three-dimensional image z-stacks of epithelium and subepithelium were generated using confocal microscopy, and from these z-stacks, total nerve length, the number of nerve branch points, substance P expression, and eosinophil peroxidase were quantified within each airway compartment.Measurements and Main Results: Nerve length and the number of branch points were significantly increased in epithelium, but not subepithelium, in chronic cough compared with healthy airways. Substance P expression was scarce and was similar in chronic cough and healthy airways. Nerve length and branching were not associated with eosinophil peroxidase nor with demographics such as age and sex in either group.Conclusions: Airway epithelial sensory nerve density is increased in chronic cough, suggesting sensory neuroplasticity contributes to cough hypersensitivity. [ABSTRACT FROM AUTHOR]

Background: Chronic wet cough in children is the hallmark symptom of protracted bacterial bronchitis (PBB) and if left untreated can lead to bronchiectasis, which is prevalent in Indigenous populations. Underrecognition of chronic wet cough by parents and clinicians and underdiagnosis of PBB by clinicians are known.Research Question: We aimed to improve recognition and management of chronic wet cough in Aboriginal children using knowledge translation (KT), a methodologic approach that can be adapted for use in Indigenous contexts to facilitate effective and sustained translation of research into practice.Study Design and Methods: A mixed-methods KT study undertaken at a remote-based Aboriginal primary medical service (February 2017 to December 2019). Our KT strategy included the following: (1) culturally secure (ie, ensuring Aboriginal people are treated regarding their unique cultural needs and differences) knowledge dissemination to facilitate family health seeking for chronic wet cough in children, and (2) an implementation strategy to facilitate correct diagnosis and management of chronic wet cough and PBB by physicians.Results: Post-KT, health seeking for chronic wet cough increased by 184% (pre = eight of 630 children [1.3%], post = 23 of 636 children [3.6%]; P = .007; 95% CI, 0.7%-4.0%). Physician proficiency in management of chronic wet cough improved significantly as reflected by improved chronic cough-related quality of life (P < .001; 95% CI, 0.8-3.0) and improved physician assessment of cough quality (P < .001; 95% CI, 10.4%-23.0%), duration (P < .001; 95% CI, 11.1%-24.1%), and appropriate antibiotic prescription (P = .010; 95% CI, 6.6%-55.7%).Interpretation: Health seeking for children with chronic wet cough can be facilitated through provision of culturally secure health information. Physician proficiency in the management of PBB can be improved with KT strategies which include training in culturally informed management, leading to better health outcomes. Comprehensive strategies that include both families and health systems are required to ensure that chronic wet cough in children is detected and optimally managed. [ABSTRACT FROM AUTHOR]

Background: Cough is one of the most common presenting symptoms to general practitioners. The objective of this article is to collate the pediatric components of the CHEST chronic cough guidelines that have recently updated the 2006 guidelines to assist general and specialist medical practitioners in the evaluation and management of children who present with chronic cough.Methods: We reviewed all current CHEST Expert Cough Panel's statements and extracted recommendations and suggestions relating to children aged ≤ 14 years with chronic cough (> 4 weeks duration). Additionally, we undertook systematic reviews to update other sections we considered relevant and important.Results: The eight recent CHEST guidelines relevant to children, based on systematic reviews, reported some high-quality evidence in the management of chronic cough in children (eg, use of algorithms and management of wet/productive cough using appropriate antibiotics). However, much evidence is still inadequate, particularly in the management of non-specific cough in the community.Conclusions: The recommendations and suggestions related to the management of chronic cough in the pediatric age group have been based upon high-quality systematic reviews and are summarized in this article. Compared to the 2006 Cough Guidelines, there is now high-quality evidence for some aspects of the management of chronic cough in children. However, further studies particularly in primary health care are required. [ABSTRACT FROM AUTHOR]

Background: Asthma and non-asthmatic eosinophilic bronchitis (NAEB) are among the commonest causes of chronic cough in adults. We sought to determine the role of non-invasive measurements of airway inflammation, including induced sputum and fractional exhaled nitric oxide, in the evaluation of cough associated with asthma, and what the best treatment is for cough due to asthma or NAEB.Methods: We undertook three systematic reviews of randomized controlled trials and observational trials of adults and adolescents > 12 years of age with a chronic cough due to asthma or NAEB. Eligible studies were identified in MEDLINE, CENTRAL, and SCOPUS and assessed for relevance and quality. Guidelines were developed and voted upon using CHEST guideline methodology.Results: Of the citations reviewed, 3/1,175, 53/656, and 6/134 were identified as being eligible for inclusion in the three systematic reviews, respectively. In contrast to established guidelines for asthma therapies in general and the inclusion in some guidelines for a role of biomarkers of airway inflammation to guide treatment in severe disease, the evidence of specific benefit related to the use of non-invasive biomarkers in patients with chronic cough due to asthma was weak. The best therapeutic option for cough in asthma or NAEB is inhaled corticosteroids followed by leukotriene receptor antagonism.Conclusions: This guideline offers recommendations on the role of non-invasive measurements of airway inflammation and treatment for cough due to asthma or NAEB based on the available literature, and identifies gaps in knowledge and areas for future research. [ABSTRACT FROM AUTHOR]

Objectives: This study was conducted in order to identify imaging features on three-dimensional computed tomography (CT) of unexplained chronic cough (UCC) patients with positive sputum cultures for filamentous Basidiomycetes (f-BM).Methods: UCC outpatients who had been given various questionnaires for cough, pulmonary function tests, and fungal cultures of sputum were evaluated. Multidetector row CT (MDCT) was performed for three-dimensional CT analysis of the lungs. Retrospective analysis was carried out with three groups: f-BM culture-positive group, other fungal culture-positive group, and culture-negative group. The Kruskal-Wallis test, analysis of variance, Fischer exact test, χ2 test, Student's t test, Mann-Whitney U test, Spearman's correlation coefficient, and Dunn-Bonferroni post hoc method were used for statistical analysis.Results: Of the 50 patients, 3 were excluded and the remaining 47 were included in the analysis. There were no significant differences in respiratory function or clinical characteristics among the three groups. The common features on high-resolution CT (HRCT) included tree-in-bud (TIB) pattern, multiple centrilobular nodules, and bronchial wall thickening. Bronchiolar mucus plugs were detected in 7 (15%) of 47 cases. Bronchiole wall thickness and %FEV1 appeared to be slightly correlated (p = 0.033, r = 0.357). The bronchiole walls were significantly thicker when mucus plugs were found (p = 0.010). Bronchiolar walls were the thickest and the score of mucus plugs was the highest in patients with f-BM culture-positive sputum (p = 0.008).Conclusions: Imaging findings for identifying f-BM culture-positive fungus-associated chronic cough (FACC) patients include high mucus plug scores and bronchiolar wall thickening on three-dimensional CT.Key Points: • Three-dimensional computed tomography helps clinicians assess patients with unexplained chronic cough and identify those with fungus-associated chronic cough. • A retrospective single-center study showed that computed tomography images in patients with filamentous Basidiomycetes cultured from sputum had mucus plugs and bronchiolar wall thickening. • UCC patients with sputum cultures positive for filamentous Basidiomycetes may have fine airway lesions that could not be detected without three-dimensional computed tomography. [ABSTRACT FROM AUTHOR]

Background: Chronic cough is a major health problem worldwide and patients are best managed in specialised tertiary centres. Little information is available on the characteristics of chronic cough patients in several European countries, including Italy. Aims: We report on the demographic, anthropometric and clinical features of a large Italian population of adult chronic cough outpatients (about 1200), who were referred to a specialised clinic in Florence, Italy, from 2008 to 2018. Methods: Demographic, environmental, lifestyle and clinical information was collected at enrolment by means of a custom-designed electronic questionnaire that only allowed for uniform responses. A subjective measure of cough-related discomfort (cough score) was also obtained using a modified Borg Scale. A multivariable logistic regression model was defined to identify the patients' characteristics associated with the cough score. Results: The characteristics of the examined population (n = 1204 outpatients) were strikingly similar to those described elsewhere. Female patients outnumbered the males [n = 847 females, (70.0%)]; both females and males displayed the same average cough score. The median age of outpatients was 61 (quartile 1 = 48; quartile 3 = 70) years; age and cough duration were unrelated to the cough score. Nasal obstruction, coughing during consultation, coughing during meals, throat clearing and the presence of respiratory abnormalities were correlated with the degree of discomfort caused by coughing. Discussion: The features of chronic cough patients are similar worldwide. The process of cough reflex hypersensitisation may soothe sex-related perceptual differences, leading to similar levels of discomfort. Conclusions: There seem to be clinical indicators that help in assessing the level of cough-related discomfort. [ABSTRACT FROM AUTHOR]

Background: We investigated preoperative and postoperative TRPV1, bradykinin (BK), and prostaglandin e‐2 (PGE2) levels in patients who underwent lung cancer surgery and evaluated the correlations between these levels and the development of acute or chronic cough after surgery. Methods: We evaluated 60 patients with non‐small cell lung cancer who underwent lobectomy at our center between August and October 2018. TRPV1, BK, and PGE2 levels were determined by enzyme‐linked immunosorbent assay and postoperative cough was assessed using the visual analog scale (VAS). Results: The postoperative serum TRPV1, BK, and PEG2 levels of the 60 patients were significantly higher than the preoperative levels (P < 0.001). Thirty‐five patients (58.3%) were diagnosed with acute cough (VAS ≥ 60 mm), and 25 were diagnosed with non‐acute cough (41.7%). Three days after surgery, the serum TRPV1, BK, and PGE2 levels were significantly higher in the acute cough group than in the non‐acute cough group (P < 0.001). Twenty‐two patients (36.7%) were diagnosed with chronic cough (VAS ≥ 60 mm), and 25 (62.3%) were diagnosed with non‐chronic cough. Eight weeks after surgery, the serum TRPV1, BK, and PGE2 levels were significantly higher in the chronic cough group than in the non‐chronic cough group (P < 0.05). Conclusions: The postoperative TRPV1, BK and PGE2 levels were significantly higher than the preoperative levels. The TRPV1 level was also higher in patients with an acute or chronic cough than in patients without. Postoperative acute or chronic cough symptoms can be improved and alleviated by blocking the TRPV1 pathway. [ABSTRACT FROM AUTHOR]

Background: In this study, we investigated the relationship between chronic cough and clinicopathological features in postoperative patients with non‐small cell lung cancer (NSCLC) and evaluated the effectiveness of acupuncture therapy for the treatment of postoperative chronic cough in patients with NSCLC. Methods: We retrospectively evaluated 171 patients with NSCLC who received lobectomy at our center between September 2017 and February 2018. The Mandarin Chinese version of the Leicester Cough Questionnaire (LCQ‐MC) was used to evaluate the degree of cough in patients. Postoperative cough was assessed by a visual analog scale (VAS). Results: The total LCQ‐MC score for the whole group was 19.79 ± 0.53 before surgery and 18.40 ± 0.70 after surgery (p < 0.001). Logistic regression analysis showed that right lung cancer, difficult airway, acute cough and history of COPD were independent predictors of chronic cough. Of the 68 patients diagnosed with chronic cough, 41 received acupuncture therapy (acupuncture therapy group), and 27 received no acupuncture therapy (no therapy group). No significant difference was found between the two groups in terms of their LCQ‐MC scores at eight weeks after surgery (p = 0.756). However, the acupuncture therapy group had a significantly higher LCQ‐MC score than the no therapy group at 10 weeks after surgery (p = 0.002). Conclusions: Right lung cancer, difficult airway, acute cough, and history of COPD are independent predictors of chronic cough after surgery. For patients with chronic cough, acupuncture therapy can shorten the recovery time and improve quality of life after surgery. [ABSTRACT FROM AUTHOR]

Background: Filamentous basidiomycetes (f-BMs) are involved in some unexplained chronic cough (UCC) cases that can be improved by the administration of antifungal agents. The disease concept was termed fungus-associated chronic cough (FACC). The current diagnostic criteria warrant environmental fungi isolation from respiratory specimens, which is hardly conceivable for such fungi. Objectives: This study aimed to detect the f-BMs Bjerkandera adusta, the most common pathogen in FACC, from respiratory specimens of patients with UCC using real-time polymerase chain reaction (PCR). It also evaluated the applicability of the PCR system to detect antifungal agent responders among patients with unexplained cough. Methods: The PCR system specific to B. adusta was developed and its utility was evaluated using sputum samples from 23 patients with chronic cough. Results:B. adusta was detected in 10 out of 14 patients with UCC (71.4%), in contrast to only 2 out of 9 patients with non-UCC (22.2%; p < 0.05 with the Fisher's exact test). The copy number of the samples correlated with the therapeutic impact score for cough symptoms following the oral administration of itraconazole. Conclusion: Development of the real-time PCR system enabled us to demonstrate that many patients with UCC might be influenced by B. adusta, a fact evidenced by the improvement of symptoms with itraconazole administration in most PCR-positive patients. This method would help in detecting itraconazole responders among patients with UCC when the isolation of f-BMs is not achievable. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the frequency of chronic cough due to dryness in the trachea and the relationship between depression and chronic cough in patients with primary Sjögren's syndrome (pSS). Patients and methods: Eighty non-smoking patients (7 males, 73 females; mean age 47.6±9.2 years; range 18 to 70 years) with newly diagnosed pSS were included. All patients were evaluated clinically, radiologically, and physiologically. Patients with cough were assessed using the Leicester Cough Questionnaire and visual analog scale. Beck Depression Inventory was used to determine the risk of depression in patients with cough. Patients with asthma, rhinosinusitis, gastrooesophageal reflux, and drug use which cause cough and pulmonary involvement in pSS were excluded. Results: Non-productive cough was detected in 30 patients (37.5%). Fourteen patients (17.5%) were admitted to the hospital with cough at least once before the diagnosis of pSS. The median time between onset of symptoms and firm diagnosis was 24 months (25-75 interquartile ranges: 3-60 months). A significant difference was observed in the Beck Depression Inventory scores between patients with and without cough. There was a significant negative relationship between Leicester Cough Questionnaire and Beck Depression Inventory scores. Conclusion: Patients with pSS often have symptoms for a long duration that mimic those of more commonly encountered non-specific pulmonary conditions. Xerotrachea should be considered in the differential diagnosis of chronic cough, especially in patients with normal pulmonary function tests and pulmonary imaging. [ABSTRACT FROM AUTHOR]

Background: The long-term prognosis of chronic cough and its determinants need to be clarified.Methods: This is a prospective, observational cohort study. Eighty-nine unselected subjects with chronic (> 8 weeks' duration) cough were carefully investigated: Clinical examination, symptom questionnaire, Leicester Cough Questionnaire (LCQ), skin prick tests, ambulatory peak expiratory flow monitoring, spirometry before and after 0.4 mgs of salbutamol, exhaled nitric oxide concentration measurement, hypertonic saline cough provocation test, and histamine bronchial provocation test. After five years, a letter was sent to the subjects containing questions about continuation of cough, smoking, indoor exposures, presence of co-morbidities, and current medication. It also contained LCQ and Cough Clinic diagnostic questionnaire. Sixty-eight subjects (76%) responded.Results: At five years, continuing regular cough was present in 31 (46%) of the subjects and continuing impairment in cough-related quality of life (less than 1.3 points' improvement in LCQ) in 32 (47%). Continuing regular cough was associated with presence of chronic rhinitis or esophageal reflux disease, baseline mild airway responsiveness to histamine, and baseline strong cough responsiveness to hypertonic saline. Continuing impairment in cough-related quality of life was associated with high body mass index, absence of atopy, absence of pets, and high number of background disorders (esophageal reflux disease, asthma, or chronic rhinitis).Conclusions: Almost half of subjects with chronic cough suffered of the disorder at five years from initial assessment. Several possible determinants of poor prognosis could be identified. [ABSTRACT FROM AUTHOR]

Background: Cough is a common symptom prompting patients to seek medical care. Like patients in the general population, patients with compromised immune systems also seek care for cough. However, it is unclear whether the causes of cough in immunocompromised patients who are deemed unlikely to have a life-threating condition and a normal or unchanged chest radiograph are similar to those in persons with cough and normal immune systems.Methods: We conducted a systematic review to answer the question: What are the most common causes of cough in ambulatory immunodeficient adults with normal chest radiographs? Studies of patients ≥ 18 years of age with immune deficiency, cough of any duration, and normal or unchanged chest radiographs were included and assessed for relevance and quality. Based on the systematic review, suggestions were developed and voted on using the American College of Chest Physicians (CHEST) methodology framework.Results: The results of the systematic review revealed no high-quality evidence to guide the clinician in determining the likely causes of cough specifically in immunocompromised ambulatory patients with normal chest radiographs.Conclusions: Based on a systematic review, we found no evidence to assess whether or not the proper initial evaluation of cough in immunocompromised patients is different from that in immunocompetent persons. A consensus of the panel suggested that the initial diagnostic algorithm should be similar to that for immunocompetent persons but that the context of the type and severity of the immune defect, geographic location, and social determinants be considered. The major modifications to the 2006 CHEST Cough Guidelines are the suggestions that TB should be part of the initial evaluation of patients with cough and HIV infection who reside in regions with a high prevalence of TB, regardless of the radiographic findings, and that specific causes and immune defects be considered in all patients in whom the initial evaluation is unrevealing. [ABSTRACT FROM AUTHOR]

Objective: Data on the aetiology of persistent cough at the transitional stage from subacute to chronic cough (>4 weeks duration) are scarce. We aimed to (1) identify the prevalence of chronic cough following acute respiratory illness (ARI) and (2) determine the diagnostic outcomes of children with chronic cough.Design: Prospective cohort study.Setting: A paediatric emergency department (ED) in Brisbane, Australia.Patients: Children aged <15 years presenting with an ARI with cough.Interventions: Children were followed weekly for 28 days;those with a persistent cough at day 28 were reviewed by a paediatric pulmonologist.Main Outcome Measures: Cough persistence at day 28 and pulmonologist diagnosis.Results: 2586 children were screened and 776 (30%) were ineligible; 839 children (median age=2.3 years, range=0.5 months to 14.7 years, 60% male) were enrolled over 2 years. Most children (n=627, 74.8%) had cough duration of <7 days at enrolment. At day 28, 171/839 (20.4%, 95% CI 17.7 to 23.1) children had persistent cough irrespective of cough duration at enrolment. The cough was wet in 59/171 (34.5%), dry in 45/171 (26.4%) and variable in 28/171 (16.1%). Of these 117 children , 117 (68.4%) were reviewed by a paediatric pulmonologist. A new and serious chronic lung disease was diagnosed in 36/117 (30.8%) children; 55/117 (47.0%) were diagnosed with protracted bacterial bronchitis.Conclusions: When chronic cough develops post-ARI, clinical review is warranted, particularly if parents report a history of prolonged or recurrent cough. Parents of children presenting acutely to ED with cough should be counselled about the development of chronic cough, as an underlying respiratory condition is not uncommon. [ABSTRACT FROM AUTHOR]

Although chronic cough in adults (cough lasting longer than eight weeks) can be caused by many etiologies, four conditions account for most cases: upper airway cough syndrome, gastroesophageal reflux disease/laryngopharyngeal reflux disease, asthma, and nonasthmatic eosinophilic bronchitis. Patients should be evaluated clinically (with spirometry, if indicated), and empiric treatment should be initiated. Other potential causes include angiotensin-converting enzyme inhibitor use, environmental triggers, tobacco use, chronic obstructive pulmonary disease, and obstructive sleep apnea. Chest radiography can rule out concerning infectious, inflammatory, and malignant thoracic conditions. Patients with refractory chronic cough may warrant referral to a pulmonologist or otolaryngologist in addition to a trial of gabapentin, pregabalin, and/or speech therapy. In children, cough is considered chronic if present for more than four weeks. In children six to 14 years of age, it is most commonly caused by asthma, protracted bacterial bronchitis, and upper airway cough syndrome. Evaluation should focus initially on these etiologies, with targeted treatment and monitoring for resolution. [ABSTRACT FROM AUTHOR]

Background: Clinical practice guidelines (CPGs) have been developed to provide health-care practitioners with the best possible evidence, but the quality of these CPGs varies greatly.Objective: The goal of this study was to systematically evaluate the quality of cough CPGs and identify gaps limiting evidence-based practice.Methods: Systematic searches were conducted to identify cough CPGs in guideline databases, developers' Websites, and Medline. Four reviewers independently evaluated eligible guidelines by using the Appraisal of Guidelines for Research and Evaluation II assessment tool. Agreement among reviewers was measured by using the intraclass correlation coefficient. The number of recommendations, strength of recommendation, and levels of evidence were determined.Results: Fifteen cough CPGs were identified. An overall high degree of agreement among reviewers was observed (intraclass correlation coefficient, 0.82 [95% CI, 0.79-0.85]). The quality ranged from good to acceptable in the scope and purpose (mean, 72%; range, 54%-93%) and clarity and presentation (mean, 68%; range, 50%-90%) domains but not in stakeholder involvement (mean, 36%; range, 18%-90%), rigor of development (mean, 36%; range, 9%-93%), applicability (mean, 23%; range, 9%-83%), and editorial independence domains (mean, 24%; range, 0-96%). Seven guidelines (46.7%) were considered "strongly recommended" or "recommended with modifications" for clinical practice. More than 70% of recommendations were based on nonrandomized studies (Level C, 30.4%) and expert opinion (Level D, 41.3%).Conclusions: The quality of cough CPGs is variable, and recommendations are largely based on low-quality evidence. There is significant room for improvement to develop high-quality guidelines, which urgently warrants first-class research to minimize the vital gaps in the evidence for formulation of cough CPGs. [ABSTRACT FROM AUTHOR]

Unlabelled: We describe the clinical, bronchoscopic, bronchoalveolar lavage (BAL) and radiographic characteristics of children whose chronic wet cough did not resolve with oral antibiotics and which led to their hospitalisation for intravenous antibiotics and airway clearance therapy. Between 2010 and 2014, medical chart review identified 22 such children. Their median cough duration was 26 weeks (interquartile range (IQR) 13-52). All received oral antibiotics immediately before their hospitalisation (median 4 weeks; IQR 4-6.5). On chest examination, seven (31 %) children had auscultatory crackles. At bronchoscopy, 9 (41 %) had tracheomalacia, 18 (86 %) demonstrated airway neutrophilia (>15 %) and 12 (57 %) grew Haemophilus influenzae from their BAL fluid. They received intravenous antibiotics (mostly cefotaxime or ceftriaxone) and airway clearance therapy as inpatients (median 12.5 days (IQR 10.8-14). All were cough-free at follow-up.Conclusion: The children's BAL characteristics are similar to those with protracted bacterial bronchitis and bronchiectasis, but their poor clinical response to oral antibiotics and non-specific chest CT findings differentiated them from these other two disorders. The findings are consistent with chronic suppurative lung disease. Intravenous antibiotics and airway clearance therapy should therefore be considered in children whose wet cough persists despite 4 weeks of oral antibiotics and where other causes of chronic wet cough are absent. What is known on this topic? • Chronic wet cough not resolving with appropriate antibiotics increases the likelihood of bronchiectasis. • Children with chronic suppurative lung disease (CSLD) have clinical features of bronchiectasis, but lack the radiographic evidence for this diagnosis.What This Study Adds: • Children with CSLD have airway neutrophilia and predominantly Haemophilus influenzae in lower airway cultures, similar to children with protracted bacterial bronchitis and bronchiectasis. • Chronic wet cough in CSLD, unresponsive to oral antibiotics, resolves with intravenous antibiotics and airway clearance therapy. [ABSTRACT FROM AUTHOR]

Background: Whether fractional exhaled nitric oxide (FeNO) measurement alone or combined with sputum eosinophil and atopy is useful in predicting corticosteroid-responsive cough (CRC) and non-CRC (NCRC) is not clear.Methods: A total of 244 patients with chronic cough and 59 healthy subjects as control were enrolled. The causes of chronic cough were confirmed according to a well-established diagnostic algorithm. FeNO measurement and induced sputum for differential cell were performed in all subjects.Results: CRC occurred in 139 (57.0%) patients and NCRC occurred in 105. The FeNO level in CRC significantly correlated with sputum eosinophils (rs = 0.583, P < .01). The median (quarter) of FeNO level in CRC was significantly higher than NCRC (32.0 ppb [19.0-65.0 ppb] vs 15.0 ppb [11.0-22.0 ppb], P < .01). FeNO of 31.5 ppb had a sensitivity and specificity of 54.0% and 91.4%, respectively, in predicting CRC from chronic cough, with a positive predictive value of 89.3% and a negative predictive value of 60.0%. If the patients had a combination of low level of FeNO ( < 22.5 ppb), normal sputum eosinophil ( < 2.5%), and absence of atopy, the sensitivity and specificity would be 30.3% and 93.5% for predicting NCRC.Conclusions: In our cohort, a high level (≥ 31.5 ppb) of FeNO indicates more likelihood of CRC, but the sensitivity is insufficient to rule out a diagnosis of CRC. A combination of low-level FeNO, normal sputum eosinophil, and absence of atopy suggests a lower likelihood of CRC. [ABSTRACT FROM AUTHOR]

The article focuses on the management of chronic refractory cough (CRC). Topics covered include CRC being defined as a cough that persists despite guideline-based treatment and is seen in 20 to 46 percent of patients presenting to specialist cough clinics , cough hypersensitivity syndrome being associated with hypersensitivity of the larynx and upper airway, and treatment methods for CRC such as speech pathology treatment.

Background: Systematic reviews were conducted to examine two related key questions (KQs) in children with chronic (> 4 weeks' duration) wet or productive cough not related to bronchiectasis: KQ1-How effective are antibiotics in improving the resolution of cough? If so, what antibiotic should be used and for how long? KQ2-When should they be referred for further investigations?Methods: The systematic reviews were undertaken based on the protocol established by selected members of the CHEST expert cough panel. Two authors screened searches and selected and extracted data. The study included systematic reviews, randomized controlled trials (RCTs), cohort (prospective and retrospective) studies, and cross-sectional studies published in English.Results: Data were presented in Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowcharts, and the summaries were tabulated. Fifteen studies were included in KQ1 (three systematic reviews, three RCTs, five prospective studies, and four retrospective studies) and 17 in KQ2 (one RCT, 11 prospective studies, and five retrospective studies). Combining data from the RCTs (KQ1), the number needed to treat for benefit was 3 (95% CI, 2.0-4.3) in achieving cough resolution. In general, findings from prospective and retrospective studies were consistent, but there were minor variations.Conclusions: There is high-quality evidence that in children aged ≤ 14 years with chronic (> 4 weeks' duration) wet or productive cough, the use of appropriate antibiotics improves cough resolution. There is also high-quality evidence that when specific cough pointers (eg, digital clubbing) are present in children with wet cough, further investigations (eg, flexible bronchoscopy, chest CT scans, immunity tests) should be conducted. When the wet cough does not improve by 4 weeks of antibiotic treatment, there is moderate-quality evidence that children should be referred to a major center for further investigations to determine whether an underlying lung or other disease is present. [ABSTRACT FROM AUTHOR]

Background: Several recent cough guidelines have advised consideration of occupational or environmental causes for chronic cough, but it is unclear how frequently this recommendation has been routinely applied. Therefore, we undertook a systematic review to address this aspect.Methods: Cough guidelines and protocols were reviewed to identify recommendations for assessment of occupational and environmental aspects of chronic cough. The systematic search previously used to identify intervention fidelity to the use of protocols for diagnosis and management of chronic cough in adults was used for this review after extension to June 2015. PubMed, Scopus, and the Cochrane Library were searched using the same search terms and inclusion criteria as previously. Papers that met our criteria were then reviewed to identify methods used to assess occupational and environmental aspects of chronic cough and the outcomes of these assessments.Results: Among the 10 general chronic cough guidelines and protocols identified, only the three published since 2006 included details advising detailed occupational and environmental assessments. One additional cough statement focused entirely on occupational cough. Of the 28 cohort studies of patients with chronic cough that specifically noted that they followed guidelines or protocols, none provided details of occupational and environmental assessments.Conclusions: Despite published recommendations, it is not apparent that occupational and environmental causes for chronic cough are addressed in detail during assessments of patients with chronic cough. This leaves open to speculation whether lack of recognition of an occupational cause may delay important preventive measures, put additional workers at risk, and/or be the reason why a chronic cough may remain unexplained. [ABSTRACT FROM AUTHOR]

Background: Unexplained chronic cough (UCC) causes significant impairments in quality of life. Effective assessment and treatment approaches are needed for UCC.Methods: This systematic review of randomized controlled trials (RCTs) asked: What is the efficacy of treatment compared with usual care for cough severity, cough frequency, and cough-related quality of life in patients with UCC? Studies of adults and adolescents aged > 12 years with a chronic cough of > 8 weeks' duration that was unexplained after systematic investigation and treatment were included and assessed for relevance and quality. Based on the systematic review, guideline suggestions were developed and voted on by using the American College of Chest Physicians organization methodology.Results: Eleven RCTs and five systematic reviews were included. The 11 RCTs reported data on 570 participants with chronic cough who received a variety of interventions. Study quality was high in 10 RCTs. The studies used an assortment of descriptors and assessments to identify UCC. Although gabapentin and morphine exhibited positive effects on cough-related quality of life, only gabapentin was supported as a treatment recommendation. Studies of inhaled corticosteroids (ICS) were affected by intervention fidelity bias; when this factor was addressed, ICS were found to be ineffective for UCC. Esomeprazole was ineffective for UCC without features of gastroesophageal acid reflux. Studies addressing nonacid gastroesophageal reflux disease were not identified. A multimodality speech pathology intervention improved cough severity.Conclusions: The evidence supporting the diagnosis and management of UCC is limited. UCC requires further study to establish agreed terminology and the optimal methods of investigation using established criteria for intervention fidelity. Speech pathology-based cough suppression is suggested as a treatment option for UCC. This guideline presents suggestions for diagnosis and treatment based on the best available evidence and identifies gaps in our knowledge as well as areas for future research. [ABSTRACT FROM AUTHOR]

Background: Use of appropriate cough pathways or algorithms may reduce the morbidity of chronic cough, lead to earlier diagnosis of chronic underlying illness, and reduce unnecessary costs and medications. We undertook three systematic reviews to examine three related key questions (KQ): In children aged ?14 years with chronic cough (> 4 weeks' duration), KQ1, do cough management protocols (or algorithms) improve clinical outcomes? KQ2, should the cough management or testing algorithm differ depending on the duration and/or severity? KQ3, should the cough management or testing algorithm differ depending on the associated characteristics of the cough and clinical history?Methods: We used the CHEST expert cough panel's protocol. Two authors screened searches and selected and extracted data. Only systematic reviews, randomized controlled trials (RCTs), and cohort studies published in English were included.Results: Data were presented in Preferred Reporting Items for Systematic Reviews and Meta-analyses flowcharts and summary tabulated. Nine studies were included in KQ1 (RCT = 1; cohort studies = 7) and eight in KQ3 (RCT = 2; cohort = 6), but none in KQ2.Conclusions: There is high-quality evidence that in children aged ?14 years with chronic cough (> 4 weeks' duration), the use of cough management protocols (or algorithms) improves clinical outcomes and cough management or the testing algorithm should differ depending on the associated characteristics of the cough and clinical history. It remains uncertain whether the management or testing algorithm should depend on the duration or severity of chronic cough. Pending new data, chronic cough in children should be defined as > 4 weeks' duration and children should be systematically evaluated with treatment targeted to the underlying cause irrespective of the cough severity. [ABSTRACT FROM AUTHOR]

Background: In developing countries like Malawi, further investigation is rare after patients with chronic cough test negative for tuberculosis. Chronic airways disease has presentations that overlap with tuberculosis. However, chronic airways disease is often unrecognised due to a lack of diagnostic services. Within developing countries, referral systems at primary health care level are weak and patients turn to unskilled informal health providers to seek health care. Delayed diagnosis and treatment of these diseases facilitates increased severity and tuberculosis transmission. The World Health Organisation developed the Practical Approach to Lung Health strategy which has been shown to improve the management of both tuberculosis and chronic airways disease. The guidelines address the need for integrated guidelines for tuberculosis and chronic airways disease. Engaging with informal health providers has been shown to be effective in improving health services uptake. However, it is not known whether engaging community informal health providers would have a positive impact in the implementation of the Practical Approach to Lung Health strategy. We will use a cluster randomised controlled trial to determine the effect of using the two interventions to improve case detection and treatment of patients with tuberculosis and chronic airways disease.Methods: A three-arm cluster randomised trial design will be used. A primary health centre catchment population will form a cluster, which will be randomly allocated to one of the arms. The first arm personnel will receive the Practical Approach to Lung Health strategy intervention. In addition to this strategy, the second arm personnel will receive training of informal health providers. The third arm is the control. The effect of interventions will be evaluated by community surveys. Data regarding the diagnosis and management of chronic cough will be gathered from primary health centres.Discussion: This trial seeks to determine the effect of Informal Health Provider and Practical Approach to Lung Health interventions on the detection and management of chronic airways disease and tuberculosis at primary care level in Malawi.Trial Registration: The unique identification number for the registry is PACTR201411000910192--21 November 2014. [ABSTRACT FROM AUTHOR]

A 66-year-old male nonsmoker from Arizona was referred to our practice for evaluation of chronic cough. He had a history of biopsy-proven relapsing polychondritis manifesting as right auricular and nasal pain and swelling 9 months prior to presentation. The onset of his cough coincided with the diagnosis of relapsing polychondritis, and he was prescribed prednisone 90 mg/d, which promptly relieved his rheumatologic and respiratory symptoms. A chest radiograph, obtained prior to the initiation of therapy, was normal. Any attempts at decreasing the dose of the glucocorticoid to < 30 mg/d resulted in recurrence of the cough but not of the auricular or nasal symptoms. A second chest radiograph done 6 months before presentation, while the patient was receiving prednisone 20 mg/d, was normal as well. In anticipation of our evaluation, he stopped all glucocorticoids for 7 days. He was not receiving any other medications, and he had no history of an atopic diathesis. [ABSTRACT FROM AUTHOR]

Background: The intensity of cough is an important determinant of cough severity. Few studies have quantified cough intensity in patients with chronic cough with objective measures. We investigated the intensity of voluntary, induced, and spontaneous cough in patients with chronic cough and healthy control subjects.Methods: Patients with chronic cough and control subjects underwent physiologic assessment of the intensity of maximum voluntary, capsaicin-induced, and spontaneous cough. Assessments included measurement of gastric pressure (Pga) and esophageal pressure (Pes) during cough, peak cough flow (PCF), expiratory muscle strength (twitch gastric pressure [TwPga]), and cough compression phase duration (CPD). Subjective perception of cough intensity was assessed using a visual analog scale (VAS).Results: Pes, Pga, and PCF during maximum voluntary cough were significantly greater in patients with chronic cough compared with control subjects (P = .003-.042). There was no difference in TwPga between patients and control subjects. CPD was increased in female patients compared with control subjects (mean ± SD, 0.50 ± 0.22 s vs 0.28 ± 0.17 s; P = .007). Mean ± SD Pes during spontaneous cough was comparable to induced cough (128 ± 28 cm H2O vs 122 ± 37 cm H2O, P = .686) but less than maximum voluntary cough (170 ± 46 cm H2O, P = .020). Median within-subject correlation coefficients between cough intensity VAS and Pes, Pga, and PCF were r = 0.82 to 0.86.Conclusions: Maximum voluntary cough intensity was increased in patients with chronic cough compared with control subjects. There was no significant difference in expiratory muscle contractility. Further studies should evaluate the compressive phase of cough in more detail. Physiologic measures of cough intensity correlated strongly with subjective perception of intensity in patients with chronic cough and may be relevant objective outcome measures for clinical studies. [ABSTRACT FROM AUTHOR]

Chronic cough is a frequent reason for medical referrals in childhood. In patients who do not have signs or symptoms of an underlying respiratory system disease and who do not respond to experimental treatment, psychogenic cough should be considered. In this paper, four patients who were referred to our department with a prediagnosis of psychogenic cough, found to have tic disorder as a result of the assessments performed and improved with antipsychotic medication are presented. The differantial diagnosis of chronic cough in children should include tic disorders as well as psychogenic cough. Tic disorders can be diagnosed easily with detailed history and their response to medical treatment is rather satisfactory. Recognition of these disorders by pediatricians will minimize erroneous diagnoses and inappropriate therapies in children with a complaint of chronic cough. [ABSTRACT FROM AUTHOR]

Initial evaluation of the patient with chronic cough (i.e., of more than eight weeks' duration) should include a focused history and physical examination, and in most patients, chest radiography. Patients who are taking an angiotensin-converting enzyme inhibitor should switch to a medication from another drug class. The most common causes of chronic cough in adults are upper airway cough syndrome, asthma, and gastroesophageal reflux disease, alone or in combination. If upper airway cough syndrome is suspected, a trial of a decongestant and a first-generation antihistamine is warranted. The diagnosis of asthma should be confirmed based on clinical response to empiric therapy with inhaled bronchodilators or corticosteroids. Empiric treatment for gastroesophageal reflux disease should be initiated in lieu of testing for patients with chronic cough and reflux symptoms. Patients should avoid exposure to cough-evoking irritants, such as cigarette smoke. Further testing, such as high-resolution computed tomography, and referral to a pulmonologist may be indicated if the cause of chronic cough is not identified. In children, a cough lasting longer than four weeks is considered chronic. The most common causes in children are respiratory tract infections, asthma, and gastroesophageal reflux disease. Evaluation of children with chronic cough should include chest radiography and spirometry. [ABSTRACT FROM AUTHOR]

Background: Paediatricians rely on cough descriptors to direct them to the level of investigations needed for a child presenting with chronic cough, yet there is a lack of published data to support this approach. A study was undertaken to evaluate (1) whether historical cough pointers can predict which children have a specific cause for their cough and (2) the usefulness of chest radiography and spirometry as standard investigations in children with chronic cough.Methods: This was a prospective cohort study of children referred to a tertiary hospital with a cough lasting >3 weeks between June 2002 and July 2004. All included children completed a detailed history and examination using a standardised data collection sheet and followed a pathway of investigation until a diagnosis was made.Results: In 100 consecutively recruited children of median age 2.8 years, the best predictor of specific cough observed was a moist cough at the time of consultation with an odds ratio (OR) of 9.34 (95% CI 3.49 to 25.03). Chest examination or chest radiographic abnormalities were also predictive with OR 3.60 (95% CI 1.31 to 9.90) and 3.16 (95% CI 1.32 to 7.62), respectively. The most significant historical pointer for predicting a specific cause of the cough was a parental history of moist cough (sensitivity 96%, specificity 26%, positive predictive value 74%).Conclusions: The most useful clinical marker in predicting specific cough is the presence of a daily moist cough. Both chest examination and chest radiographic abnormalities are also useful in predicting whether children have a specific cause of their cough. [ABSTRACT FROM AUTHOR]

There is no consensus as to the best diagnostic strategy for chronic cough. Many protocols combine empirical trials of treatment with laboratory investigations. More precise diagnostic tools and improved therapeutic options are required. Until then, the management of chronic cough will remain a clinical challenge. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux disease (GERD) can be overlooked as the cause of chronic cough (CC) when typical gastrointestinal symptoms are absent or minimal. We analyzed the outcomes of Nissen fundoplication (NF) for patients who failed medical therapy for CC attributable only to GERD (G-CC). We performed a prospective outcome evaluation of 21 consecutive patients with G-CC undergoing NF from 1997 to 2000 at a tertiary care university hospital.Materials and Methods: Twenty-one patients without prior antireflux surgeries had G-CC diagnosed by a clinical profile and 24-h pH monitoring showing a cough-reflux correlation. Respiratory symptoms alone were present in 53% of patients. NF was performed when G-CC persisted despite intensive medical therapy, including an antireflux diet. Preoperatively, all patients underwent 24-h pH monitoring, esophageal manometry, barium swallow, gastric emptying study, bronchoscopy, and upper endoscopy. NF was utilized in all cases, laparoscopically in 18. Before and after surgery, patients graded their cough severity using the Adverse Cough Outcome Survey (ACOS). Quality of life was measured using the Sickness Impact Profile (SIP).Results: Postoperatively, 18 patients (86%) reported an improvement of their cough. G-CC considerably improved in 16/21 patients (76%), with complete resolution in 13 patients (62%). Mild to moderate improvement was found in 2 patients (10%). Patient-reported cough severity (ACOS) and quality of life (SIP) both significantly improved early (6-12 weeks) postoperatively and persisted during the long-term (1 year) follow-up. The average hospital length of stay was 1.78 +/- 0.2 (l-4) days for the laparoscopic (n = 18) and 6.3 +/- 1.2 (4-8) days for the open surgery (n = 3) groups.Conclusion: Twenty-four-hour esophageal pH monitoring is a valuable tool for preoperative cough-reflux correlation. Antireflux surgery is effective in carefully selected patients whose refractory CC is attributable only to GERD. NF controls the severity of cough while improving the quality of life. Outcomes are further enhanced using laparoscopic procedures with shorter hospital stays. [ABSTRACT FROM AUTHOR]

In addition to heartburn and regurgitation, cough is a frequent nonspecific complaint of patients with gastroesophageal reflux disease. The incidence of alternative etiologies for patients with chronic cough who are undergoing antireflux surgery is not known. To determine this, and the response of chronic cough to fundoplication, we performed a retrospective review of 129 patients with proven gastroesophageal reflux referred for surgical therapy. Chronic cough was present in 37 (29%) preoperatively. No differences were found in age, sex, or preoperative manometric findings between those with and without chronic cough. Patients with cough had a higher number of lower esophageal reflux events on preoperative 24-hour pH testing, and were more likely to have persistent dysphagia after surgery. Fifty-nine percent of patients with cough had an alternative etiology for cough, compared to 36% of those without cough. Of the common alternative etiologies, only a history of postnasal drip occurred more frequently in those with cough. Complete resolution of cough occurred in 24 patients (64%), with another 10 (27%) reporting significant improvement. The average cough score improved significantly regardless of which coexisting etiology the patients may have had. Additionally, heartburn and regurgitation were improved in 94% of all patients. (J Gastrointest Surg 2002;6:17–21.) [Copyright &y& Elsevier]

Objective: Chronic cough is one of the most common causes of absence from school, education and disturbances in ordinary works. According to its high prevalence in our population and lack of study (ies) about this in our country, this study has been performed to estimate chronic cough preformed, to estimate chronic cough prevalence and determinate its relations to variables such as age, sex, location, parent's education and smoking. Materials and methods: This descriptive analytic cross- sectional study has been performed on 3222 students of primary school during 1379-80. Date was acquired by interview, completion of questionaries' and sanitary service records. Then information became analyzed and tested by person chi-square test if needed. Results: Findings showed that the prevalence of chronic cough in our population was 3.6% (3.5% male and 3.8% female). Among 3222 students, 1748 (962 male and 786 female) subjects were from urban and 1474 (719 male and 755 female) rural population. 118 cases had chronic cough in urban population the prevalence was 4 percent (3.2% male and 4.7% female) and in rural population 3.2% (3.6% male and 2.9% female). Among 118 involved students, 60 cases had a smoker father (50.8%) and among 3104 others, 1438 cases had a non-smoker father (46.3%). Conclusion: Our finding showed that sex, age location smoking and parent's education had relation to chronic cough of students. So we decide that for reducing the chronic cough prevalence in our society especially primary school ones. Health and sanity education planned and distributed in a wide array to diagnostic modalities and appropriate therapeutic plans for reduction of chronic cough complication. [ABSTRACT FROM AUTHOR]

The article offers information on chronic cough. Topics discussed include common causes such as heartburn, asthma and certain medicines, diagnostic tests such as chest x-rays, lung scans and breathing tests, and issues to address in medical consultations. The causes of chronic cough in children such as respiratory infections, heartburn, and asthma are also mentioned.

The article offers information on managing acute and chronic cough. The condition is described as acute, lasting less than three weeks, or chronic when it may persist for more than eight weeks. Cough is experienced by most adults between two and five episodes per year. Several symptoms and treatments are also discussed.

Discusses research on a pathogenic triad in the diagnosis of chronic cough. Reference to a study by B. C. Palombini, et al., from the August 1999 issue of the `Chest'; Prevalence of chronic cough among nonsmokers; Findings of the study which was conducted on nonsmoker patients with chronic cough; Treatment of patients with chronic cough; Causes of chronic cough.