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Zhang M, Sykes DL, Brindle K, Sadofsky LR, Morice AH. Chronic cough-the limitation and advances in assessment techniques. J Thorac Dis 2022; 14:5097-5119. [PMID: 36647459 PMCID: PMC9840016 DOI: 10.21037/jtd-22-874] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/04/2022] [Indexed: 11/23/2022]
Abstract
Accurate and consistent assessments of cough are essential to advance the understanding of the mechanisms of cough and individualised the management of patients. Considerable progress has been made in this work. Here we reviewed the currently available tools for subjectively and objectively measuring both cough sensitivity and severity. We also provided some opinions on the new techniques and future directions. The simple and practical Visual Analogue Scale (VAS), the Leicester Cough Questionnaire (LCQ), and the Cough Specific Quality of Life Questionnaire (CQLQ) are the most widely used self-reported questionnaires for evaluating and quantifying cough severity. The Hull Airway Reflux Questionnaire (HARQ) is a tool to elucidate the constellation of symptoms underlying the diagnosis of chronic cough. Chemical excitation tests are widely used to explore the pathophysiological mechanisms of the cough reflex, such as capsaicin, citric acid and adenosine triphosphate (ATP) challenge test. Cough frequency is an ideal primary endpoint for clinical research, but the application of cough counters has been limited in clinical practice by the high cost and reliance on aural validation. The ongoing development of cough detection technology for smartphone apps and wearable devices will hopefully simplify cough counting, thus transitioning it from niche research to a widely available clinical application.
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Affiliation(s)
- Mengru Zhang
- Centre for Clinical Science, Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK;,Department of Pulmonary and Critical Care Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Dominic L. Sykes
- Centre for Clinical Science, Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK
| | - Kayleigh Brindle
- Centre for Clinical Science, Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK
| | - Laura R. Sadofsky
- Centre for Clinical Science, Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK
| | - Alyn H. Morice
- Centre for Clinical Science, Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK
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Kim SH, Kim DM, Park HE, Shin YB, Lee BJ, Jang MH, Yoon JA. Gold Standard? Method of Citric Acid Solution Swallowing Test as a Screening Test for Patients with Tracheostomy. Dysphagia 2021; 37:533-539. [PMID: 33905045 DOI: 10.1007/s00455-021-10300-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/31/2021] [Indexed: 09/29/2022]
Abstract
This study aimed to apply various ranges of citric acid levels in the mouth and T-cannula to compare the validity with instrumental aspiration measures in patients with tracheostomy. Sixty-one patients underwent the citric acid cough reflex test (CRT) and videofluoroscopic swallowing study (VFSS). Citric acid was delivered via facemask and T-cannula at concentrations of 0.4 mol/L, 0.6 mol/L, and 0.8 mol/L. Further, we recorded the coughing count and presence of ≥ 2 (C2) and ≥ 5 (C5) coughs. CRT via facemask at 0.4 mol/L C2, 0.6 mol/L C5, and 0.8 mol/L C2 and C5 were significantly associated with the presence of tracheal aspiration during VFSS. The sensitivity and specificity were optimized at 0.8 mol/L C2 for mouth inhalation and at 0.8 mol/L C5 for T-cannula inhalation. There was a significant difference in the coughing count during CRT at 0.4 mol/L and 0.8 mol/L via mouth inhalation between patients with or without tracheal aspiration, but not via T-cannula. The AUC for 0.8 mol/L facemask inhalation was 0.701. The optimal cut-off value of coughing count was thrice with 84.62% sensitivity and 50.00% specificity on the ROC curve. Afferent sensory nerve desensitization around and below the tracheostomy site could affect coughing reflex initiation and decrease the sensitivity of detecting aspiration in tracheotomized patients. The citric acid CRT via facemask can reliably detect tracheal aspiration and presence of coughing reflex compared to that via T-cannula in patients with tracheostomy.
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Affiliation(s)
- Sang Hun Kim
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Dong-Min Kim
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Ho Eun Park
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Yong Beom Shin
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Byeong Ju Lee
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Myung Hun Jang
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea
| | - Jin A Yoon
- Department of Rehabilitation Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-Ro Seo-Gu, Busan, 602-739, Republic of Korea.
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Wallace E, Guiu Hernandez E, Ang A, Macrae P. Quantifying test-retest variability of natural and suppressed citric acid cough thresholds and urge to cough ratings. Pulm Pharmacol Ther 2019; 58:101838. [DOI: 10.1016/j.pupt.2019.101838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 11/25/2022]
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Wallace E, Guiu Hernandez E, Ang A, Hiew S, Macrae P. A systematic review of methods of citric acid cough reflex testing. Pulm Pharmacol Ther 2019; 58:101827. [PMID: 31326628 DOI: 10.1016/j.pupt.2019.101827] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION This systematic review summarises and appraises methods of citric acid cough reflex testing (CRT) documented in published literature. METHODS Electronic databases, MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus were searched up to and including 11th February 2018. Studies reporting a method of citric acid CRT, published in peer-reviewed journals in English or Spanish, were assessed for the inclusion criteria. Of the selected studies, information on the instrumentation and CRT protocol was extracted. RESULTS A total of 129 studies were included. Instrumentation and protocols differed widely across studies. Reporting of methods of citric acid CRT was sub-standard, with many crucial methodological components omitted from published manuscripts, preventing their full replication. CONCLUSIONS Considerable methodological variability exists for citric acid CRT in published literature. The findings suggest that caution is warranted in comparing citric acid cough thresholds across studies. Full replication of previously published methods of citric acid CRT is limited due to crucial elements of the citric acid CRT protocol being omitted from published manuscripts. These findings have implications on the use of citric acid CRT in clinical and pharmaceutical studies to evaluate the effects of antitussive medications and cough therapies.
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Affiliation(s)
- Emma Wallace
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand.
| | - Esther Guiu Hernandez
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Alicia Ang
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Sarah Hiew
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Phoebe Macrae
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
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Methods of Cough Assessment. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2019; 7:1715-1723. [DOI: 10.1016/j.jaip.2019.01.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/24/2022]
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Cho PS, Fletcher HV, Turner RD, Jolley C, Birring SS. Impaired cough suppression in chronic refractory cough. Eur Respir J 2019; 53:13993003.02203-2018. [DOI: 10.1183/13993003.02203-2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/18/2019] [Indexed: 11/05/2022]
Abstract
Functional brain imaging in individuals with chronic cough demonstrates reduced activation in cortical regions associated with voluntary cough suppression. Little is known about the ability of patients with chronic cough to suppress cough. This study aimed to compare the ability to voluntarily suppress cough during inhaled capsaicin challenge in participants with chronic refractory cough with that in healthy controls. In addition, this study aimed to assess the repeatability of capsaicin challenge test with voluntary cough suppression.Participants with chronic refractory cough and healthy controls underwent inhaled capsaicin challenge tests while attempting to suppress their cough responses. After 5 days, either a conventional capsaicin challenge test with no cough suppression attempt, or a repeat test with an attempt at cough suppression was performed. Threshold capsaicin concentrations required to elicit one, two and five coughs were calculated by interpolation. Objective 24-h cough frequency was measured in individuals with chronic refractory cough.Healthy controls were able to suppress capsaicin-evoked cough while participants with chronic refractory cough were not. Geometric mean±sd capsaicin dose thresholds for five coughs with (CS5) and without (C5) suppression attempts were 254.40±3.78 versus 45.89±3.95 µmol·L−1, respectively, in healthy controls (p=0.033) and 3.34±5.04 versus 3.86±5.13 µmol·L−1, respectively, in participants with chronic refractory cough (p=0.922). Capsaicin dose thresholds for triggering five coughs with self-attempted cough suppression were significantly lower in participants with chronic refractory cough than in healthy controls; geometric mean±sd 4.94±4.43 versus 261.10±4.34 µmol·L−1, respectively; mean difference (95% CI) 5.72 (4.54–6.91) doubling doses (p<0.001). Repeatability of cough suppression test in both patients and healthy controls was high; intraclass correlation coefficients of log(CS5) values 0.81 and 0.87, respectively. CS5 was associated with objective cough frequency (ρ=−0.514, p=0.029).Participants with chronic refractory cough were less able to voluntarily suppress capsaicin-evoked cough compared to healthy controls. This may have important implications for the pathophysiology and treatment of chronic cough.
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Rai Z, Fowles H, Wright C, Howard J, Morice A. The effect of pH on citric acid cough challenge: A randomised control trial in chronic cough and healthy volunteers. Respir Physiol Neurobiol 2018. [DOI: 10.1016/j.resp.2018.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Does diurnal variation in cough reflex testing exist in healthy young adults? Respir Physiol Neurobiol 2017; 239:70-74. [DOI: 10.1016/j.resp.2017.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 11/19/2022]
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Fowles HE, Rowland T, Wright C, Morice A. Tussive challenge with ATP and AMP: does it reveal cough hypersensitivity? Eur Respir J 2017; 49:49/2/1601452. [PMID: 28179439 DOI: 10.1183/13993003.01452-2016] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/02/2016] [Indexed: 12/11/2022]
Abstract
Recent studies have demonstrated that blockade of P2X3 ATP receptors can profoundly inhibit chronic cough. We have considered whether inhaled ATP produces a tussive response and whether chronic cough patients are hypersensitive to inhaled ATP compared to healthy volunteers.A standardised inhalational cough challenge was performed with ATP and AMP. We randomised 20 healthy volunteers and 20 chronic cough patients as to the order of challenges. The concentration of challenge solution causing at least five coughs (C5) was compared for ATP and AMP.The study population consisted of six male and 14 female volunteers in each group. Two out of 19 healthy volunteers coughed with AMP (one volunteer could not take part in this challenge) and none reached C5. Eight out of 20 chronic cough patients coughed with AMP and two reached C5. Of the 20 healthy volunteers, 18 coughed with ATP, with 15 reaching C5. All 19 chronic cough patients completing the ATP challenge coughed with ATP and 18 reached C5. The chronic cough patients had a greater cough response at lower concentrations of ATP.The greater potency of ATP versus AMP in the inhalational challenge suggests that tussive responses are mediated through members of the P2X purinergic receptor family. This acute effect was, however, not sufficient to explain cough hypersensitivity syndrome.
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Affiliation(s)
- Helen Elizabeth Fowles
- Hull York Medical School Centre for Cardiovascular and Metabolic Research, Respiratory, Castle Hill Hospital, Cottingham, UK
| | - Tim Rowland
- Castle Hill Hospital, Respiratory, Cottingham, UK
| | - Caroline Wright
- Hull York Medical School Centre for Cardiovascular and Metabolic Research, Respiratory, Castle Hill Hospital, Cottingham, UK
| | - Alyn Morice
- Hull York Medical School Centre for Cardiovascular and Metabolic Research, Respiratory, Castle Hill Hospital, Cottingham, UK
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Vilardell N, Rofes L, Nascimento WV, Muriana D, Palomeras E, Clavé P. Cough reflex attenuation and swallowing dysfunction in sub-acute post-stroke patients: prevalence, risk factors, and clinical outcome. Neurogastroenterol Motil 2017; 29. [PMID: 27424849 DOI: 10.1111/nmo.12910] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/22/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Cough and swallowing impairments in post-stroke patients (PSP) have been associated with increased risk for respiratory complications. AIMS To assess the prevalence of alterations in protective cough responses in subacute PSP and its association with oropharyngeal dysphagia (OD), clinical, and neurotopographic stroke factors and clinical outcomes. METHODS Three months after stroke, the cough reflex test (CRT) was performed by nebulizing incremental citric acid concentrations (7.8-1000 mmol L-1 ) to determine the concentration that elicited two and five coughs; OD was assessed by the volume-viscosity swallow test. Clinical and neurotopographic stroke risk factors and complications (readmissions, respiratory infections, institutionalization, and mortality) were recorded from 3 to 12 months post-stroke. RESULTS We included 225 PSP. Prevalence of impaired CRT was 5.8%, that of OD was 40.4% (20.4% with impaired safety of swallow), and of both impairments was, 1.8%. No specific risk factors associated with impaired CRT were found; however, hemorrhagic, wide circulation infarction (TACI), and brainstem strokes delayed the cough response. OD was associated with age, TACI and poor functional and nutritional status. Outcome of PSPs was unaffected by impaired CRT but OD and impaired safety of swallow increased institutionalization, respiratory infections, and mortality with the poorest outcome for those with both impairments. CONCLUSIONS Prevalence of subacute post-stroke OD and swallow safety impairments was much higher than CRT attenuation, and risk factors strongly differed suggesting that the swallow response receives a stronger cortical control than the cough reflex. OD has a greater impact on PSP clinical outcome than impaired cough, the poorest prognosis being for patients with both airway protective dysfunctions.
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Affiliation(s)
- N Vilardell
- Unitat d'Exploracions Funcionals Digestives, Department of Surgery, Hospital de Mataró, Universitat Autònoma de Barcelona, Mataró, Spain
| | - L Rofes
- Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain
| | - W V Nascimento
- Medical School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - D Muriana
- Neurology Unit, Hospital de Mataró, Universitat Autònoma de Barcelona, Mataró, Spain
| | - E Palomeras
- Neurology Unit, Hospital de Mataró, Universitat Autònoma de Barcelona, Mataró, Spain
| | - P Clavé
- Unitat d'Exploracions Funcionals Digestives, Department of Surgery, Hospital de Mataró, Universitat Autònoma de Barcelona, Mataró, Spain.,Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain.,Fundació Institut d'Investigació en Ciències de la Salut, Germans Trias i Pujol, Badalona, Spain
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Mukhopadhyay I, Kulkarni A, Aranake S, Karnik P, Shetty M, Thorat S, Ghosh I, Wale D, Bhosale V, Khairatkar-Joshi N. Transient receptor potential ankyrin 1 receptor activation in vitro and in vivo by pro-tussive agents: GRC 17536 as a promising anti-tussive therapeutic. PLoS One 2014; 9:e97005. [PMID: 24819048 PMCID: PMC4018403 DOI: 10.1371/journal.pone.0097005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/15/2014] [Indexed: 01/22/2023] Open
Abstract
Cough is a protective reflex action that helps clear the respiratory tract which is continuously exposed to airborne environmental irritants. However, chronic cough presents itself as a disease in its own right and despite its global occurrence; the molecular mechanisms responsible for cough are not completely understood. Transient receptor potential ankyrin1 (TRPA1) is robustly expressed in the neuronal as well as non-neuronal cells of the respiratory tract and is a sensor of a wide range of environmental irritants. It is fast getting acceptance as a key biological sensor of a variety of pro-tussive agents often implicated in miscellaneous chronic cough conditions. In the present study, we demonstrate in vitro direct functional activation of TRPA1 receptor by citric acid which is routinely used to evoke cough in preclinical and clinical studies. We also show for the first time that a potent and selective TRPA1 antagonist GRC 17536 inhibits citric acid induced cellular Ca+2 influx in TRPA1 expressing cells and the citric acid induced cough response in guinea pigs. Hence our data provides a mechanistic link between TRPA1 receptor activation in vitro and cough response induced in vivo by citric acid. Furthermore, we also show evidence for TRPA1 activation in vitro by the TLR4, TLR7 and TLR8 ligands which are implicated in bacterial/respiratory virus pathogenesis often resulting in chronic cough. In conclusion, this study highlights the potential utility of TRPA1 antagonist such as GRC 17536 in the treatment of miscellaneous chronic cough conditions arising due to diverse causes but commonly driven via TRPA1.
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Affiliation(s)
- Indranil Mukhopadhyay
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Abhay Kulkarni
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Sarika Aranake
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Pallavi Karnik
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Mahesh Shetty
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Sandeep Thorat
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Indraneel Ghosh
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Dinesh Wale
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Vikram Bhosale
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
| | - Neelima Khairatkar-Joshi
- Biological Research, Glenmark Research Centre, Glenmark Pharmaceuticals Ltd., Navi Mumbai, Maharashtra, India
- * E-mail:
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Renner B, Mueller CA, Shephard A. Environmental and non-infectious factors in the aetiology of pharyngitis (sore throat). Inflamm Res 2012; 61:1041-52. [PMID: 22890476 PMCID: PMC3439613 DOI: 10.1007/s00011-012-0540-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 07/22/2012] [Accepted: 07/25/2012] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES The aim of this review is to examine the causes, pathophysiology and experimental models of non-infectious pharyngitis (sore throat). INTRODUCTION The causes of sore throat can be infectious (viruses, bacteria, and fungi) or non-infectious, although the relative proportion of each is not well documented. METHODS A PubMed database search was performed for studies of non-infectious sore throat. RESULTS AND CONCLUSIONS Non-infectious causes of sore throat include: physico-chemical factors, such as smoking, snoring, shouting, tracheal intubation, medications, or concomitant illness; and environmental factors including indoor and outdoor air pollutants, temperature and humidity, and hazardous or occupational irritants. The pathophysiology underlying non-infectious sore throat is largely uncharacterised, although neurogenic inflammation looks to be a promising candidate. It is likely that there will be individual disposition factors or the coincidence of more than one irritant with possible--up to now unknown--interactions between them. Therefore, experimental models with defined conditions and objective endpoints are needed. A new model using cold dry air to directly induce pharyngeal irritation in humans, with pharyngeal lavage to measure biomarkers, may provide a useful tool for the study of mechanisms and treatment of non-infectious sore throat.
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Affiliation(s)
- Bertold Renner
- Department of Experimental and Clinical Pharmacology, University of Erlangen-Nuremberg, Krankenhausstr. 9, 91054 Erlangen, Germany.
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Cough hypersensitivity syndrome is an important clinical concept: a pro/con debate. Lung 2011; 190:3-9. [PMID: 22186805 DOI: 10.1007/s00408-011-9351-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 11/16/2011] [Indexed: 10/14/2022]
Abstract
The major etiologies of chronic cough are generally accepted to consist of upper airway cough syndrome (formerly postnasal drip syndrome), eosinophilic airway inflammation (asthma, nonasthmatic eosinophilic bronchitis), and gastroesophageal reflux disease (GERD). However, only a small percentage of patients with these very common conditions suffers from chronic cough. Furthermore, acute cough due to viral upper respiratory tract infection (URI) is almost always a transient, self-limited condition, yet in a small subgroup of patients, URI heralds the onset of chronic, refractory cough. The cough hypersensitivity syndrome has been proposed to explain the occurrence of chronic cough in a subgroup of patients exposed to the same putative triggers as the vast majority of the population in whom chronic cough does not result. Although conceptually the cough hypersensitivity syndrome may be intellectually satisfying, differences of opinion remain as to whether this newly recognized entity is of clinical significance, i.e., useful for the treatment of patients suffering from chronic cough. The Third American Cough Conference, held in New York in June 2011, provided an ideal forum for the debate of this issue between two internationally recognized authorities in the field of cough.
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