title: Development of chronic airway obstruction in patients with eosinophilic bronchitis: a prospective follow-up study.
abstract: OBJECTIVE
  Eosinophilic bronchitis (EB) presents as a chronic cough and sputum eosinophilia without airflow limitation or bronchial hyperreactivity. Its long-term clinical course remains unknown. This study evaluated how frequently EB recurs and whether it develops chronic airway obstruction.
  
  
  METHODS
  This study was a prospective analysis.
  
  
  METHODS
  Cough severity, FEV(1), provocative concentration of methacholine causing a 20% fall in FEV(1), and sputum eosinophil percentages were serially measured in 36 subjects for up to 48 months. All subjects inhaled corticosteroids until cough subsided.
  
  
  RESULTS
  Five of the twenty four follow-up subjects (21%) had a recurrent episode of EB 4 to 6 months after disappearance of the first episode of EB (recurrent eosinophilic bronchitis). Progressive FEV(1) reduction > 20% was observed in three of the subjects, including a subject with asthma developing at the ninth month. Nineteen subjects had no recurrence of cough (nonrecurrent eosinophilic bronchitis) and no progressive FEV(1) reduction > 20%. However, sputum eosinophilia recurred between 4 months and 24 months in 10 subjects. Mean values of FEV(1) at the ninth and 12th months of the study were significantly lower in the recurrent eosinophilic bronchitis group than in the nonrecurrent eosinophilic bronchitis group (p < 0.01).
  
  
  CONCLUSIONS
  These results suggest that repeated episode of EB is associated with the development of chronic airflow obstruction, including asthma.
authors.affiliation: Asthma and Allergy Research Group, Soonchunhyang University Hospital, Bucheon, Korea.
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Young Mok
authors.initials: YM
authors.lastname: Lee
authors.forename: An Soo
authors.initials: AS
authors.lastname: Jang
authors.forename: June Hyuk
authors.initials: JH
authors.lastname: Lee
authors.forename: Young
authors.initials: Y
authors.lastname: Hwangbo
authors.forename: Do Jin
authors.initials: DJ
authors.lastname: Kim
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Park
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D017677:Age Distribution; D001985:Bronchial Provocation Tests / Q000379:methods; D001991:Bronchitis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D002908:Chronic Disease; D003371:Cough / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D018450:Disease Progression; D004802:Eosinophilia / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000209:etiology*; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013183:Sputum / Q000166:cytology*; D018709:Statistics, Nonparametric
chemical_list: D000305:Adrenal Cortex Hormones