From the Guidelines
Wheezing is not a reliable indicator of the severity of cough variant asthma (CVA), as CVA is characterized by a persistent dry cough without significant wheezing or shortness of breath. To assess CVA severity, focus on:
- Frequency and intensity of cough
- Impact on daily activities and sleep
- Response to bronchodilators
- Lung function tests (spirometry) For management, the most recent and highest quality study suggests starting with inhaled corticosteroids as first-line treatment 1. Specifically, inhaled corticosteroids such as fluticasone 100-250 mcg twice daily for 4-8 weeks can be used, with the option to add a long-acting beta-agonist (e.g., salmeterol) if needed, and using short-acting beta-agonists (e.g., albuterol) as needed for symptom relief 1. Monitor treatment response through symptom improvement and lung function tests, and adjust medication dosage as needed. The absence of wheezing in CVA does not indicate less severe disease, as CVA can still significantly impact quality of life and may progress to classic asthma if left untreated, due to airway hyperresponsiveness that may not always manifest as audible wheezing but can still cause significant bronchial inflammation and remodeling over time 1.
From the Research
Reliability of Wheezing as an Indicator of CVA Severity
- The development of wheezing in patients with cough variant asthma (CVA) may not be a reliable indicator of the severity of the condition, as wheezing can occur at various stages of the disease 2, 3.
- A study found that early inhaled corticosteroid treatment can prevent the development of wheezing in patients with CVA, suggesting that wheezing may not be a direct indicator of disease severity 2.
- Another study found that patients with CVA who developed wheezing were sensitized to larger numbers of allergens and had higher rates of sensitization to certain allergens, such as house dust mite and dog dander 4.
Clinical Features of CVA
- CVA is characterized by chronic cough without wheezing or any apparent cause, with a normal chest X-ray and spirometry but with bronchial hyperresponsiveness to methacholine, and relief of cough after bronchodilator treatment 5.
- Patients with CVA may experience coughing more frequently at night and early in the morning, and may have lower early morning peak expiratory flow (PEF) values compared to evening PEF values 5.
Treatment and Prognosis of CVA
- Inhaled corticosteroids are effective in treating CVA and can improve symptoms and reduce airway inflammation 5, 6.
- The prognosis of CVA is variable, and some patients may progress to classic asthma with wheezing, while others may achieve remission 2, 6.
- Avoidance of relevant allergens may be essential to prevent the progression of CVA to classic asthma 4.