Chronic cough with a history of excessive sputum production. The spectrum and frequency of causes, key components of the diagnostic evaluation, and outcome of specific therapy

Chest. 1995 Oct;108(4):991-7. doi: 10.1378/chest.108.4.991.


Study objective: To determine (1) the spectrum and frequency of causes of chronic cough with a history of excessive sputum production (CCS) and (2) the response of these causes to specific therapy.

Study design: Prospective study utilizing the anatomic diagnostic protocol originally developed to diagnose chronic cough.

Patients: Seventy-one immunocompetent adults who complained of expectoration of greater than 30 mL of sputum per day.

Location: University hospital pulmonary outpatient clinic.

Results: Patients were seen an average of 4.2 times over 4.6 months before a specific diagnosis was made. The cause of CCS was determined in 97%. It was due to one cause in 38%, 2 in 36%, and three in 26%. Postnasal drip syndrome (PNDS) was a cause 40% of the time, asthma 24%, gastroesophageal reflux disease (GERD) 15%, bronchitis 11%, bronchiectasis 4%, left ventricular failure 3%, and miscellaneous causes 3%. Among patients with a normal chest radiograph who were nonsmokers and not taking an angiotensin converting enzyme inhibitor; CCS was due to PNDS, or asthma, or GERD, or all three in 100% of cases. Chest radiograph, methacholine inhalation challenge, 24-h esophageal pH monitoring, bronchoscopy, and spirometry with bronchodilator each had a sensitivity and negative predictive value of 100%. Chest radiograph and barium swallow had positive predictive values of only 38% and 30%, respectively.

Conclusions: (1) The anatomic diagnostic protocol for cough is also valid for CCS; (2) the major causes of chronic excessive sputum production and chronic cough are so similar that CCS should be considered a form of chronic cough; (3) the evaluation of CCS is more complicated and takes longer than the evaluation of chronic cough; (4) the major strength of the laboratory diagnostic protocol is that it reliably rules out conditions; (5) the outcome of specific therapy is almost always successful; and (6) the term "bronchorrhea" can be misleading if it is applied to excessive sputum production before a specific diagnosis of its source is made since the most common cause of excessive sputum that is expectorated (PNDS) is a disorder of the upper respiratory tract. Therefore, nonspecific therapies theoretically aimed at reducing mucus production in the lower respiratory tract are not likely to be helpful.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Chi-Square Distribution
  • Chronic Disease
  • Combined Modality Therapy
  • Cough / diagnosis
  • Cough / etiology*
  • Cough / physiopathology
  • Cough / therapy
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Remission Induction
  • Respiratory Function Tests
  • Sputum / metabolism*
  • Treatment Outcome