title: Interpreting the histopathology of chronic cough: a prospective, controlled, comparative study.
abstract: OBJECTIVE
  Trauma from chronic coughing produces airway inflammation similar to diseases causing cough.
  
  
  METHODS
  Prospective, cross-sectional, controlled, clinicopathologic correlation study in four groups: group 1, cough from intrapulmonary diseases; group 2, cough from extrapulmonary diseases; group 3, cough that was unexplained; and group 4, nonsmoking, asymptomatic control subjects.
  
  
  METHODS
  Patients with chronic cough underwent a standardized workup including endobronchial biopsies before treatment. Causes were determined by a favorable response to therapy. Bronchial biopsy samples from control subjects were obtained from surgical specimens.
  
  
  RESULTS
  There were 24 adult subjects (13 women and 11 men) with mean cough duration of 8.6 +/- 7.4 years (+/- SD). Thirteen patients had cough due to a specific disease: intrapulmonary diseases in 5 patients, and extrapulmonary diseases in 8 patients. Eleven patients had unexplained cough. Compared to control subjects, there was minimal-to-moderate chronic inflammation in all coughers (p < or = 0.0004), in group 1 (p < or = 0.039), group 2 (p = 0.061), and group 3 (p < or = 0.025) diseases that were not correlated with cough duration. There was no difference in type of inflammation, cough duration, or smoking history between groups, nor were there histologic differences between subjects with explained causes of cough compared with unexplained cough.
  
  
  CONCLUSIONS
  Our findings suggest that airway inflammation associated with chronic cough, assessed on morphologic appearance and inflammatory cell counting in hematoxylin-eosin-prepared samples, may be due to the trauma of coughing, and the inflammation may be similar to that seen with diseases putatively thought to cause chronic cough. Investigators must be cautious when attributing pathogenic importance to observed inflammatory changes in airways of coughing subjects.
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA. irwinr@ummhc.org
authors.forename: Richard S
authors.initials: RS
authors.lastname: Irwin
authors.forename: Robert
authors.initials: R
authors.lastname: Ownbey
authors.forename: Philip T
authors.initials: PT
authors.lastname: Cagle
authors.forename: Stephen
authors.initials: S
authors.lastname: Baker
authors.forename: Armando E
authors.initials: AE
authors.lastname: Fraire
mesh_terms: D001249:Asthma / Q000150:complications / Q000473:pathology; D001980:Bronchi / Q000473:pathology*; D001991:Bronchitis / Q000150:complications / Q000473:pathology; D001999:Bronchoscopy; D002908:Chronic Disease; D003371:Cough / Q000209:etiology / Q000473:pathology*; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D012907:Smoking / Q000473:pathology; D003074:Solitary Pulmonary Nodule / Q000150:complications / Q000473:pathology