Small Airway Dysfunction in Cough Variant Asthma: Prevalence, Clinical, and Pathophysiological Features

Area of Science:

• Pulmonology
• Respiratory Medicine
• Asthma Research

Background:

• Small airway dysfunction (SAD) is common in asthma, affecting inflammation, severity, and control.
• The prevalence, clinical correlations, and treatment response of SAD in cough variant asthma (CVA) require clarification.

Purpose of the Study:

• To determine the prevalence of SAD in CVA patients.
• To investigate the relationship between SAD and clinical/pathophysiological features in CVA.
• To assess changes in small airway function after antiasthmatic treatment in CVA.

Main Methods:

• Retrospective analysis of 120 corticosteroid-naïve CVA patients.
• Evaluated SAD using spirometry parameters (MMEF, FEF50, FEF75).
• Assessed cough severity (VAS), sputum cells, FeNO, and airway hyper-responsiveness.

Main Results:

• SAD was present in 60.8% of CVA patients before treatment.
• SAD correlated with longer cough duration, older age, and poorer spirometry.
• SAD persisted in 54.3% of patients after 2 months of treatment, despite symptom and inflammation improvement.

Conclusions:

• Small airway dysfunction is highly prevalent in CVA and often persists post-treatment.
• SAD in CVA exhibits distinct clinical and pathophysiological characteristics.
• Further research is needed to understand the long-term implications and management of SAD in CVA.