Bronchial asthma versus paroxysmal vocal-fold dysfunction in patients with exercise-induced respiratory symptoms

Abstract

Background Most pulmonary physicians are treating patients with symptoms of wheezes as bronchial asthma. However, acute wheezing may occur owing to a distinct disease called vocal-fold dysfunction (VFD).Aim The aim was to differentiate bronchial asthma from VFD in patients experiencing exercise-induced respiratory symptoms.Patients and methods A total of 40 patients with exercise-induced respiratory symptoms who were admitted to Chest Diseases Department of Alexandria Main University Hospital and 20 healthy volunteers were recruited from March 2017 to October 2018 after obtaining informed consents from the participants and approval of the local ethical committee. All underwent full history taking, clinical examination, spirometry, auditory perceptual assessment, laryngovideostroboscopy, and acoustic analysis. Speech therapy was done for patients with VFD followed by spirometry after at least 6 months of treatment.Results VFD was higher in females, smokers, and patients with high BMI. Forced vital capacity (FVC), first second of forced vital capacity (FEV1), and FEV1/FVC showed statistically significant differences, to be lower in asthmatic patients. Forced expiratory flow at 50% of the vital capacity to forced inspiratory flow at 50% of the vital capacity (FEF50/FIF50) showed statistically significant difference, to be more than one in patients with VFD (P=0.001). Comparing patients with VFD before and after speech therapy showed no statistic differences regarding FVC, FEV1, and FEV1/FVC; however, strikingly there was a significant reduction in FEF50/FIF50 after speech therapy (P=0.001). Positive correlation was found between FEF50/FIF50 and BMI, Jitter%, and Shimmer dB.Conclusion Early recognition and precise identification of VFD can avoid inappropriate treatment. Spirometric evaluation is an available procedure that can be implemented for both identifying and monitoring of VFD. FEF50/FIF50 ratio more than one is suggestive of VFD. Speech therapy can be applied as a treatment of such condition.