title: [Etiological diagnosis of chronic cough with unknown causes].
abstract: OBJECTIVE
  To explore the spectrum and frequency of causes for chronic cough in Chinese patients.
  
  
  METHODS
  86 patients with chronic cough were enrolled in the study. The diagnostic procedure was based on the anatomical protocol for diagnosing chronic cough designed by Irwin, and additional cytological assay was performed for sputum induced by hypertonic saline aerosol inhalation. The efficacy of therapy specific to the diagnosis was evaluated.
  
  
  RESULTS
  Definite diagnosis was made in 77 (89.5%) out of the 86 patients with chronic cough. The most common causes included cough variant asthma (CVA) (24/86, 27.9%), postnasal drip syndrome (PNDs) (22/86, 25.6%), eosinophilic bronchitis (EB) (13/86, 15.1%), and gastroesophageal reflux (GER) (12/86, 14.0%). After active management based on the diagnosis, cough improved in 72 patients (93.5%).
  
  
  CONCLUSIONS
  In addition to CVA, PNDs and GER, eosinophilic bronchitis is also an important cause of chronic cough. A positive response to the specific therapy is essential to a definite diagnosis.
authors.affiliation: Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital, Guangzhou Medical College, Guangzhou 510120, China.
authors.forename: Hong-ming
authors.initials: HM
authors.lastname: Ma
authors.forename: Li-xing
authors.initials: LX
authors.lastname: Zhu
authors.forename: Ke-fang
authors.initials: KF
authors.lastname: Lai
authors.forename: Tong
authors.initials: T
authors.lastname: Zhu
authors.forename: Bao-qing
authors.initials: BQ
authors.lastname: Sun
authors.forename: Ming
authors.initials: M
authors.lastname: Ouyang
authors.forename: Nan-shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications; D001991:Bronchitis / Q000150:complications; D002908:Chronic Disease; D003371:Cough / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged