Allergy.  1995 Jun;15(2):223-229.

Airway responsiveness in patients with chronic cough

• Yoo B
• Choi SW
• Moon HB

Abstract

Chronic cough is one of the most common respiratory symptoms and can be the sole presenting manifestation of bronchial asthma. Sometimes it is difficult to find out the etiology because of its heterogenous pathogenesis. We investigated the prevalence of airway hyperresponsiveness and their relation to clinical or laboratory features in patients with chronic cough. We studied 69 individuals over the age 16. who had presented with cough of more than 8 weeks' duration without history of dyspnea or wheezing. Methacholine bronchial challenge tests were done at concentrations of 0.625-25mg/ml, and positive response was defined as a reduction in FEV1 by 20% or more. Results were as follows. 1) Forty-two percent of patients showed positive responses to methacholine challenge and 32% of patients developed cough during challenge test without expiratory flow limitation. 2) The results of bronchial provocation test were not related to patients' age, basal lung functions, recurrency of cough, presence of postnasal drip syndrome or atopy. These results indicated that airway responsiveness is not predictable on the basis of clinical features or ordinary laboratory findings in patients with chronic cough and that non-specific bronchial provocationtest is mandatory in evaluating these patients. Also suggested was the existence of the 'cough-type' bronchial responsiveness which could be separated from the 'constriction- type' response.

MeSH Terms

Asthma
Bronchial Provocation Tests
Cough*
Dyspnea
Humans
Lung
Methacholine Chloride
Prevalence
Respiratory Sounds
Methacholine Chloride