What is cough variant asthma (CVA)?

From the Guidelines

Cough variant asthma (CVA) is a subtype of asthma characterized by a persistent, dry cough as the sole or primary symptom, often without wheezing or shortness of breath 1.

Key Characteristics

• CVA presents a challenge in diagnosis, as physical examination and spirometry findings may be entirely normal 1
• Methacholine inhalation challenge testing can demonstrate the presence of bronchial hyperresponsiveness, which is a key feature of asthma 1
• The diagnosis of CVA is only confirmed after the resolution of cough with antiasthmatic therapy 1 ### Treatment Approach
• The therapeutic approach to CVA is similar to that of the typical form of asthma, with most patients responding to inhaled bronchodilators and inhaled corticosteroids 1, 2
• Inhaled corticosteroids, such as fluticasone (250-500mcg via inhalation, 1-2 puffs twice daily), are recommended as first-line treatment for CVA 2
• A subgroup of patients may require the addition of leukotriene receptor antagonists and/or a short course of oral corticosteroids 1
• Beta-agonists, such as albuterol (2.5-5mg via inhalation, 1-2 puffs as needed), may also be considered in combination with inhaled corticosteroids 2 ### Important Considerations
• Asthma should be considered as a potential etiology in any patient with chronic cough, as it is a common condition that is commonly associated with cough 1
• Clinical suspicion must remain high, as CVA may present with no other symptoms of asthma 1

From the Research

Definition and Characteristics of Cough Variant Asthma (CVA)

• CVA is defined as a persistent nonproductive cough with minimal wheezing or dyspnea 3
• The uncontrolled coughing may interfere with sleep, work, and social activities, and can be extremely distressing, especially when it precipitates fecal or urinary incontinence 3
• CVA is characterized by a heightened cough response to methacholine-induced bronchoconstriction, and eosinophilic inflammation of the central to peripheral airway 4

Diagnosis of CVA

• The diagnosis of CVA is commonly made based on therapeutic diagnostic procedures, such as a trial of prednisone or bronchodilator therapy 3, 4
• A diagnosis of CVA is made when a chronic cough is associated with airway hyperresponsiveness and a favorable response to asthma therapy in the absence of other discernible cause 5
• The sensitivity of cough receptors located in the superficial layer of the airway wall is normal in CVA, but heightened in atopic cough 4

Treatment and Management of CVA

• Inhaled corticosteroids are the choice drugs for the treatment of CVA, as they relieve cough and decrease bronchial hyperresponsiveness 3, 5
• The therapeutic approach to CVA is similar to that of the typical form of asthma, and may include beta2-agonists, leukotriene receptor antagonists, and inhaled corticosteroids 4
• Maintenance therapy with combination therapy, such as salmeterol/fluticasone propionate, provides further improvements in cough symptoms, pulmonary function, and airway inflammation, and discontinuation of the therapy may cause worsening of the disease 6

Natural History and Prognosis of CVA

• The natural history of CVA is variable, and a significant proportion of patients followed over time develop the classic signs and symptoms of asthma 7
• For many patients, cough resolves without need for further treatment, but early intervention with long-term anti-inflammatory agents may be recommended to prevent the development of typical asthma 6, 7