Type 2 Inflammation and Upper Gastrointestinal Symptom Traits in the Clinical Course of Chronic Cough: A Real-World Cough Clinic Study

Background Type 2 inflammation and upper gastrointestinal symptom traits are common in chronic cough but their relationship with cough resolution in practice remains unclear. Methods This retrospective study included 256 patients with chronic cough followed up for ≥3 months between 2012 and 2020. Type 2 inflammation was defined as peripheral blood eosinophils ≥300 cells/μL, FeNO ≥25 ppb, or serum total IgE ≥100 IU·mL −1 . Reflux symptoms (RS) and dysmotility symptoms (DS) were assessed using the modified Frequency Scale for the Symptoms of GERD. Severe RS was defined as RS >7, and DS >1 was considered a dysmotility-related symptom trait. Time to physician-assessed cough resolution was evaluated using Kaplan–Meier analysis and Cox proportional hazards models. Results Patients with severe RS had a longer median time to cough resolution than those with non-severe RS (3.8 versus 2.0 months) and a higher 12-month rate of unresolved cough (20.3% versus 16.3%; p<0.05). Among patients with severe RS, those without type 2 inflammation had a higher 12-month rate of unresolved cough than those with type 2 inflammation (28.5% versus 13.3%; p<0.01). In the non-severe RS subgroup, patients with a dysmotility-related symptom trait had a lower 12-month rate of unresolved cough than those without this trait (10.7% versus 24.1%; p<0.01). In multivariable Cox analysis, type 2 inflammation was associated with a greater likelihood of cough resolution, whereas severe RS was associated with delayed cough resolution. Conclusion Type 2 inflammation and severe RS were independently associated with physician-assessed cough resolution. Dysmotility-related symptoms may characterize heterogeneity within RS-defined subgroups.