Bronchial asthma: what is different in patients with and without chronic cough?

Objective: Chronic cough (CC)-i.e., cough lasting for ≥ 8 weeks- is a common and burdensome symptom in asthma patients; however, its pathophysiological mechanisms and clinical relevance remain unclear. We sought to investigate clinical, functional, and inflammatory differences between asthma patients with chronic cough (ACC) and those without. (ANCC). Methods: We included 344 patients with moderate-to-severe asthma evaluated at a referral center from 2017 to 2024. Clinical data, lung function, inflammatory biomarkers, and health resource utilization were compared between ACC and ANCC. Further analyses stratifying patients by sputum eosinophil percentage (≥ 3% vs. < 3%) and CC were also performed. Multivariate logistic regression was used to identify factors independently associated with chronic cough. Results: ACC (n = 124; 36%) had significantly worse asthma control (ACQ: p = 0.001), as well as higher number of exacerbations (p = 0.011), health care utilization, (p < 0.0001) and treatment dose of inhaled corticosteroids, (p = 0.004) when compared with ANCC. Despite similar lung function and inflammatory biomarkers, dyspnea, nocturnal symptoms, Cumulative Illness Rating Scale scores, and health care use were independently associated with CC. Further stratifications by sputum eosinophil percentage and CC revealed that ACC experienced a greater disease burden, regardless of whether sputum eosinophil percentage was ≥ 3% or < 3%. Conclusions: CC identifies a subgroup of asthma patients with poorer disease control, increased health care needs, and distinct clinical profiles, independently of airway inflammation. Routine recognition of cough as a symptom in asthma assessment may guide referral and personalized management.