Differences and similarities between patients with cough variant asthma and cough predominant asthma

Abstract

Introduction: asthma is a common cause of chronic cough (CC). In patients with cough and bronchial hyperresponsiveness but with no signs of airway obstruction cough variant asthma (CVA) may be diagnosed. Cough predominant asthma (CPA) may be recognized when cough is the principal, but not the only symptom and variable airflow limitation is present. Objective: to compare clinical and inflammatory parameters in patients with CVA and CPA. Methods: non-smoking adults who were diagnosed because of CC in our department between 2015 and 2018 were analyzed. CVA or CPA were diagnosed based on the criteria given above. Duration of cough, cough severity (measured by Leicester Cough Questionnaire (LCQ) and VAS score), results of spirometry, severity of bronchial hyperresponsiveness (PC20), FeNO, blood eosinophilia and induced sputum (IS) cellular composition were compared. Results: among 189 patients diagnosed because of CC, asthma was diagnosed in 47 patients (24.9%): CVA and CPA in 31 and 16 patients respectively. Patients with CVA were older than those with CPA ( 67 vs 59.5 years, p=0.024). CVA was characterized by a later onset than CPA (in 57 vs 42 years, p=0.03). Body mass index (BMI) was higher in CVA patients (31.4 vs 25.6 kg/m2, p=0.001). There were no differences in cough severity, coincidence of upper airway cough syndrome, gastroesophageal reflux or atopy, FeNO, PC20, blood and IS eosinophilia and FEV1 (% of predicted value). Conclusions: with the exception of a later onset and higher BMI in patients with CVA, the clinical features of asthma in patients with CVA and CPA are comparable.