title: Causes and clinical features of subacute cough.
abstract: OBJECTIVE
  Cough lasting > 3 weeks has been defined as chronic cough. However, it might be more persuasive to divide cough into subacute, lasting 3 to 8 weeks, and chronic, lasting > 8 weeks. We evaluated the causes and clinical courses of subacute cough, and the value of the bronchoprovocation test and induced sputum examination (IS).
  
  
  METHODS
  Nonsmoking patients with cough of 3 to 8 weeks duration were enrolled into the study. Patients with dyspnea, basal FEV1 of < 70% predicted, abnormal findings on a plain chest radiograph or physical examination were excluded. We prescribed an antihistamine-decongestant for patients who were suspected to have postinfectious cough or postnasal drip. If patients had positive results on a bronchoprovocation test or IS, therapy with inhaled corticosteroids was substituted according to an algorithmic approach.
  
  
  RESULTS
  One hundred eighty-four patients (77 men and 107 women) were evaluated; the mean age of the study group was 47.5 years. Eighty-nine of 184 patients had postinfectious cough. Cough resolved without treatment in 62 patients. Twenty-nine of 43 patients with positive bronchoprovocation test results had cough-variant asthma.
  
  
  CONCLUSIONS
  Postinfectious cough was the most common cause of subacute cough. The spontaneous resolution of cough was frequent in patients with subacute cough. Unless asthma was strongly suspected, the performance of the bronchoprovocation test could be delayed until after empirical treatment had been administered.
authors: Division of Allergy, Department of Medicine, Samsung Medical Center, 50 Ilwon-dong, Kangnam-Gu, Seoul, Korea 135-710.
authors: Nam-Hee
authors: NH
authors: Kwon
authors: Mi-Jung
authors: MJ
authors: Oh
authors: Tae-Hoon
authors: TH
authors: Min
authors: Byung-Jae
authors: BJ
authors: Lee
authors: Dong-Chull
authors: DC
authors: Choi