Clinical characteristics and effects of inhaled corticosteroid in patients with post-COVID-19 chronic cough during the Omicron variant outbreak

Background Chronic cough is a common symptom in patients post the coronavirus disease 2019 (COVID-19). In this study, we aimed to investigate the efficacy of inhaled corticosteroids (ICS) and the clinical characteristics of patients with post-COVID-19 chronic cough during the Omicron era. Methods An ambispective, longitudinal cohort study was conducted that included patients with post-COVID-19 who attended the respiratory clinic at our hospital between January 1, 2023, and March 31, 2023 with a complaint of persistent cough lasting more than 8 weeks. At 30 and 60 days after the first clinic visit for post-COVID-19 chronic cough, enrolled patients were prospectively followed up. We compared the changes in symptoms and pulmonary function between patients receiving ICS treatment (ICS group) and those not receiving ICS treatment (NICS group) at the two visits. Results A total of 104 patients with post-COVID-19 chronic cough were enrolled in this study (ICS group, n = 51; NICS group, n = 53). The most common symptoms accompanying post-COVID-19 chronic cough were sputum (58.7%, 61/104) and dyspnea (48.1%, 50/104). Seventy-one (82.6%, 71/86) patients had airway hyperresponsiveness, and 49 patients (47.1%, 49/104) were newly diagnosed with asthma. Most patients (95.2%, 99/104) exhibited improvement at 60 days after the first visit. The pulmonary function parameters of the patients in the ICS group were significantly improved compared to the baseline values (P < 0.05), and the improvement in the FEV1/FVC was significantly greater than that in the NICS group (P = 0.003) after 60 days. Conclusions Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may contribute to the pathogenesis of asthma, which could be the underlying cause of persistent cough post-COVID-19 infection. Post-COVID-19 chronic cough during the Omicron era was often accompanied by sputum, dyspnea, and airway hyperresponsiveness. ICS treatment did not have a significant impact on symptom management of post-COVID-19 chronic cough; however, it can improve impaired lung function in in these individuals.