title: A worldwide survey of chronic cough: a manifestation of enhanced somatosensory response.
abstract: Reports from individual centres suggest a preponderance of females with chronic cough. Females also have heightened cough reflex sensitivity. Here we have reviewed the age and sex of unselected referrals to 11 cough clinics. To investigate the cause of any observed sex dimorphism, functional magnetic resonance imaging of putative cough centres was analysed in normal volunteers. The demographic profile of consecutive patients presenting with chronic cough was evaluated. Cough challenge with capsaicin was undertaken in normal volunteers to construct a concentration-response curve. Subsequent functional magnetic resonance imaging during repeated inhalation of sub-tussive concentrations of capsaicin observed areas of activation within the brain and differences in the sexes identified. Of the 10,032 patients presenting with chronic cough, two-thirds (6591) were female (mean age 55 years). The patient profile was largely uniform across centres. The most common age for presentation was 60-69 years. The maximum tolerable dose of inhaled capsaicin was lower in females; however, a significantly greater activation of the somatosensory cortex was observed. Patients presenting with chronic cough from diverse racial and geographic backgrounds have a strikingly homogeneous demographic profile, suggesting a distinct clinical entity. The preponderance of females may be explained by sex-related differences in the central processing of cough sensation.
authors.affiliation: Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK A.H.Morice@hull.ac.uk.
authors.forename: Alyn H
authors.initials: AH
authors.lastname: Morice
authors.affiliation: Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Jakes
authors.affiliation: Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK.
authors.forename: Shoaib
authors.initials: S
authors.lastname: Faruqi
authors.affiliation: Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.
authors.forename: Surinder S
authors.initials: SS
authors.lastname: Birring
authors.affiliation: Dept of Medicine, Institute of Clinical Science, The Queen's University of Belfast, Belfast, UK.
authors.forename: Lorcan
authors.initials: L
authors.lastname: McGarvey
authors.affiliation: Dept of Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, MD, USA.
authors.forename: Brendan
authors.initials: B
authors.lastname: Canning
authors.affiliation: Centre for Respiratory and Allergy, University of Manchester, University Hospital of South Manchester, Manchester, UK.
authors.forename: Jaclyn A
authors.initials: JA
authors.lastname: Smith
authors.affiliation: Dept of Respiratory Medicine, North Tyneside General Hospital, Northumbria Healthcare NHSFT, North Shields, UK.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Parker
authors.affiliation: Royal Brompton and Harefield NHS Trust and National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Kian Fan
authors.initials: KF
authors.lastname: Chung
authors.affiliation: Dept of Clinical Research, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical College, Guangzhou, China.
authors.forename: Kefang
authors.initials: K
authors.lastname: Lai
authors.affiliation: Nuffield Dept of Medicine Research Building, University of Oxford, Oxford, UK.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Pavord
authors.affiliation: Isala klinieken, Zwolle, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: van den Berg
authors.affiliation: Dept of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Woo-Jung
authors.initials: WJ
authors.lastname: Song
authors.affiliation: Dept of Internal Medicine/Respiratory Medicine and Allergology, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Millqvist
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Parkville, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Farrell
authors.affiliation: School of Biomedical Sciences, University of Queensland, Brisbane, Australia.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Mazzone
authors.affiliation: Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Dicpinigaitis
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002211:Capsaicin; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D003371:Cough / Q000503:physiopathology*; D005260:Female; D014943:Global Health; D064368:Healthy Volunteers; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012018:Reflex; D012042:Registries; D012189:Retrospective Studies; D017678:Sex Distribution; D012737:Sex Factors; D013003:Somatosensory Cortex / Q000503:physiopathology; D055815:Young Adult
chemical_list: D002211:Capsaicin