Airway mucus plugs in chronic cough- preliminary study.

The presence of airway mucus plugs (MP) identified in chest computed tomography (CT) in patients with asthma or COPD is associated with impaired airway function, airway inflammation and worse clinical outcomes. The significance of MP in chronic cough (CC) remains unknown. The aim of the study was to assess the prevalence of MP in patients with CC and their relationship with cough characteristics and efficacy of treatment. A retrospective analysis was performed using data of patients with CC referred to our clinic between 2018-2022. Adults with determined cause of CC, treatment follow-up and chest CT scanning were included. CT scans were assessed by two observers to analyse the presence of MP. We analysed data from 38 patients (26 F/12M; 9 ex-smokers/29 never smokers) with median age 55.5 yrs, median cough duration 48 months and median cough severity (measured by visual analogue scale, VAS) 70 mm. Cough variant asthma (CVA), upper airway cough syndrome (UACS) and gastroesophageal reflux (GER) were diagnosed in 22 (58%), 33 (87%) and 30 (79%), respectively. Among all 38 patients, 9 (23.7%) had at least one MP revealed in chest CT. CVA was diagnosed in 6 subjects (16%) with MP. We did not observe differences in the prevalence of MP in relation to diagnosis of CVA, UACS, GER or sputum production. Patients with MP had longer cough duration (180 vs 48 months, p=0.013), but did not differ from those without MP in terms of age, BMI, smoking history, cough severity and blood eosinophils count. Good response to antitussive therapy considered as decrease in VAS ≥ 20 mm was higher in patients without MP (55% vs. 13.8%, p=0.029). MP are present in patients with CC and might be related to longer cough duration and worse therapy outcome.