Cough-Variant Asthma Underdiagnosed Worldwide
Chronic cough-variant asthma (CVA) represents a frequently overlooked asthma phenotype in which cough is the dominant symptom, according to a Journal of Allergy and Clinical Immunology: In Practice review.
Study Findings / Main News
CVA is defined by persistent, paroxysmal cough without typical asthma symptoms such as wheezing, dyspnea, or chest tightness. It is estimated to account for 25%–42% of chronic cough cases seen in clinical practice but is likely underrecognized due to diagnostic challenges. Pathophysiologically, CVA shares mechanisms with classic asthma—including bronchial hyperresponsiveness and eosinophilic airway inflammation—but cough intensity can be high despite minimal airflow obstruction.
Diagnostically, clinicians should integrate objective measures of variable expiratory airflow limitation and bronchial hyperresponsiveness where feasible, the authors advise, although standard spirometry may be insensitive early in disease. Unlike classic asthma, CVA cough may not uniformly improve with bronchodilators alone.
Inhaled corticosteroids (ICS), alone or with long-acting β-agonists, remain first-line therapy to target underlying type 2 inflammation and improve cough outcomes.
Clinical Implications
For clinicians in North America, Europe, and Asia, high index of suspicion for CVA among patients presenting with chronic cough can reduce diagnostic delay and morbidity. Recognizing that up to 4 in 10 chronic cough patients may have CVA has implications for resource-limited settings where underdiagnosis is common. Early implementation of guideline-based diagnostic algorithms—including bronchoprovocation testing or fractional exhaled nitric oxide where available—can differentiate CVA from other causes such as nonasthmatic eosinophilic bronchitis.
Clinicians should be aware that cough-predominant asthma may not respond to short-acting bronchodilators alone; rather, early ICS therapy appears critical to reduce symptom burden and may prevent progression to classic asthma phenotypes. Knowledge of CVA’s clinical spectrum supports tailored management plans and reinforces the importance of comprehensive assessment in patients with unexplained chronic cough.
Reference: Cox JK, Lockey R, Cardet JC. Cough-variant asthma: a review of clinical characteristics, diagnosis, and pathophysiology. J Allergy Clin Immunol Pract. 2025;13(3):490–498. DOI: 10.1016/j.jaip.2024.11.005
