Background: Coughing may be produced by a number of
different disorders in distinct anatomic sites. Chronic cough causes
major functional limitation in a considerable patient population and
requires careful evaluation.
nonsmoking patients of both genders who complained of cough for≥
3 weeks and had normal findings on plain chest radiographs were
studied prospectively. Their histories were obtained, and
physical examinations were performed. The diagnostic workup included
pulmonary function tests, CT of the paranasal sinuses and chest,
carbachol provocation test, fiberoptic rhinoscopy, fiberoptic
bronchoscopy, and 24-h esophageal pH monitoring. The final diagnosis
depended on clinical, radiologic, and laboratory findings; a successful
response to therapy was required for confirmation.
Results: The causes of chronic cough were determined in all
patients. Coughing was due to a single cause in 30 patients (38.5%)
and multiple causes in 48 patients (61.5%). The five most important
causative factors were asthma (46 patients; 58.9%), postnasal drip
syndrome (PNDS; 45 patients; 57.6%), gastroesophageal reflux disease
(GERD; 32 patients; 41.1%), bronchiectasis (14 patients; 17.9%), and
tracheobronchial collapse (11 patients; 14.1%).
Interpretation: Asthma, PNDS, and GERD, alone or in
combination, were responsible for 93.6% of the cases of chronic cough.
The presence of these three conditions was so frequent that the
expression “pathogenic triad of chronic cough” should be
acknowledged in specialized literature. It is essential to
consider pulmonary and extrapulmonary causes in order to prescribe a
successful specific therapy for chronic