Lund–Mackay Computed Tomography Score Is Associated With Obstructive Pulmonary Function Changes in Chronic Cough Patients

Background: A remarkable relationship between upper airway conditions and lung diseases has been reported. At the same time, sinonasal findings in chronic cough patients have not been fully examined. Objective: The purpose of this study is to show paranasal sinus findings and lung function in chronic cough patients without asthma and chest X-ray abnormalities. Methods: A total of 1412 patients with persistent cough were enrolled in this study. Of these patients, 376 patients were evaluated for further examination, as the patients with asthma and/or chest X-ray abnormality were excluded from the study. Normal control subjects without any chronic respiratory symptoms were also recruited. Pulmonary function was examined by spirometry. A bronchial obstruction reversibility test was applied. The Lund–Mackay computed tomography (CT) score, peripheral blood eosinophil count, and immunoglobulin E concentration in serum samples were examined. The Sino-Nasal Outcome Test was used to determine the severity of clinical symptoms. Results: The patients with an abnormal soft tissue shadow in the paranasal sinus had significant obstructive lung function. The percent predicted forced expiratory volume in 1 second (FEV_1.0) and the FEV_1.0/forced vital capacity ratio negatively correlated with Lund–Mackay CT scores both before and after bronchodilator inhalation. There was a statistically significant correlation between pulmonary function and eosinophil count. Conclusion: The patients with chronic cough frequently had paranasal sinus abnormalities. The Lund–Mackay CT score may be useful for assessing the condition of the lower airway in chronic cough patients. Upper airway examinations should play a part in the management of chronic cough.