J Asthma Allergy Clin Immunol.
1998 Jun;18(2):222-231.
A prospective study for spectrum and frequency of chronic cough in patients
visiting out-patient clinic
Abstract
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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.