A prospective study for spectrum and frequency of chronic cough in patients visiting out-patient clinic / 천식및알레르기

ABSTRACT

BACKGROUND: Chronic cough is commonly defined as a persistent or recurrent cough exceeding 3 weeks duration and the prevalence of chronic cough is reported to range from 14-23% among non-smoking adults. Irwin et al previously reported that common causes of chronic cough are postnasal drip syndrome asthma, and gastroesophageal reflux using the anatomic and diagnostic protocol. OBJECTIVE: To determine the spectrum and frequency of chronic cough and to aid establishing algorithmic approach for chronic cough. MATERIALS AND METHOD: We prospectively evaluated 105 consecutive and unselected immunocompetent patients complaining of chronic cough utilizing modified anatomic and diagnostic protocol proposed by Irwin et al. Initial diagnosis was made by history, physical examination and laboratory test including spirometry, methacholine provocation test, and 24 hour pH monitoring. Specific treatment was done based upon initial diagnosis and cough score was compared before and after treatment. Reassessment was done in case of treatment failure. RESULT: The causes of cough were determined in 100 of 105 patients(95% ). Cough was due to one condition in 94.8% and two in 15.2%. 121 causes of cough were identified and their spectrum and frequency were found to be postnasal drip syndrome (39.3% ), asthma (32.2% ), gasteroesophageal reflux (14.1%), chronic bronchitis (5.0%), others (4.1% drug-induced, bronchiolitis, endobronchial tuberculosis, and lung cancer). History about nasal symptoms was useful, but history about gastroesophageal reflux were not useful for the diagnosis. CONCLUSION: The results suggest that anatomic and diagnostic approach for evaluating chronic cough is also useful in Korea and the most common causes of chronic cough are postnasal drip syndrome, asthma and gastroesophageal reflux.