Cough variant asthma: A diagnostic challenge with a simple solution

An empirical trial with inhaled corticosteroid (ICS) should be considered when clinical suspicion of cough variant asthma (CVA) is high after ruling out other common causes of chronic cough, advised Professor Roland Buhl from the Pulmonary Department, Johannes Gutenberg University Mainz, Mainz, Germany, at the 29^th Hong Kong Medical Forum. 

“Given the diagnostic challenges and the benefits of early intervention, patients with suspected CVA may be treated with a low-dose ICS for 2–3 months, followed by evaluation of clinical response. From my 40 years of experience, improvement or resolution of cough in response to ICS is pivotal in confirming the diagnosis,” said Buhl. “Despite patients’ concerns, we may rest assured that there are no relevant risks of side effects associated with such short-term use of low- to medium-dose ICS.”

Paroxysmal coughing is the predominant symptom of CVA, often occurring in response to typical asthma triggers in the absence of other typical asthma symptoms (such as shortness of breath, wheezing and chest tightness). “It may be difficult to distinguish CVA from other causes of chronic cough [cough lasting >8 weeks], as spirometry may be normal, variable airflow limitation may be identified only from bronchial provocation testing, and persistent cough is the only or most prominent symptom presented,” Buhl pointed out. [Am J Respir Cell Mol Biol 2025;72:231-232; J Allergy Clin Immunol Pract 2025;13:490-498; Ann Allergy Asthma Immunol 2025;134:639-648]

“CVA, the most common cause of chronic cough, together with upper airway cough syndrome [formerly known as postnasal drip syndrome] and gastroesophageal disease, account for >90 percent of chronic cough cases,” noted Buhl. Other common causes include post-infectious hypersensitivity, cigarette-smoking and angiotensin-converting enzyme inhibitor use. [Ann Allergy Asthma Immunol 2025;134:639-648] 

Notably, CVA is more prevalent in Asia (China, Hong Kong, Japan) than in the West (US or UK) (≥30 vs <24 percent). [Chest 2013;143:613-620; Respir Med 2009;103:1492-1497; Am Rev Respir Dis 1990; 141:640-647; Am J Respir Crit Care Med 1999;160:406-410]

“Regardless of spirometry, bronchoprovocation or fractional exhaled nitric oxide [FeNO] results, the solution is the same – treat with ICS, check clinical response after 8–12 weeks, and importantly, maintain treatment if symptoms improve, otherwise the risk of developing full-blown asthma is significant,” advised Buhl. Up to half of patients with CVA may progress to typical asthma later. [J Allergy Clin Immunol Pract 2025;13:490-498; www.ginasthma.org. Global Strategy for Asthma Management and Prevention, 2025] 

“These recommendations are supported by both Chinese guidelines and the Global Initiative for Asthma [GINA]. They recommend that CVA be treated similarly to asthma in general,” said Buhl.

The Asthma Group of Chinese Thoracic Society’s Chinese National Guideline on Diagnosis and Management of Cough (2021) recommend fixed-dose combination of ICS with long-acting beta agonist (LABA) or ICS alone for at least 8 weeks as first-line treatment for CVA. A leukotriene receptor antagonist, and if necessary, short-term oral corticosteroid, may also be added. [Zhonghua Jie He He Hu Xi Za Zhi 2022;45:13-46] GINA’s Global Strategy for Asthma Management and Prevention (2025 update) advises following usual recommendations for asthma for treatment of CVA. [www.ginasthma.org]