Cough is a common and important sign/symptom in patients with
idiopathic pulmonary fibrosis (IPF). However, there have been few reports focusing on
cough, and the exact mechanisms for
cough in patients with IPF have remained unclear. The objective of this study was to investigate the clinical features of IPF patients with refractory
cough and to clarify mechanisms for
cough in these patients. We retrospectively reviewed the files of patients with the diagnosis of IPF at Kanazawa University Hospital and compared the clinical features of IPF patients with refractory
cough with the clinical features of IPF patients without refractory
cough. Among a total of 23 patients with IPF, 10 patients (43.5%) had
chronic cough. Of the ten patients, seven patients had concomitant conditions that could lead to
cough. Of these seven patients, the
cough of four patients was resolved
after treatment of their concomitant condition. Finally, among the 23 patients there were 6 (26.1%) with refractory
cough associated with IPF. Significant differences were seen between the following clinical features of IPF patients with or without refractory
cough, respectively, as follows: lower body mass index (BMI; 18.8±2.5 vs. 22.8±2.5 kg/m2, P<0.01), lower forced vital capacity (FVC; 77.5%±30.4% predicted vs. 99.9%±0.53% predicted, P=0.046), and presence of
traction bronchiectasis and distorted airway architecture on high-resolution computed tomography (HRCT; 83.3% vs. 11.8%, P<0.01). The difference between the proportions of patients with or without refractory
cough with
capsaicin cough sensitivity was not significant. Mechanical stress on the airways due to
traction bronchiectasis and distorted airway architecture is a possible mechanism for
cough in IPF patients.