What is the initial treatment for cough variant asthma after an upper respiratory infection (URI)?

Initial Treatment for Cough Variant Asthma After URI

Patients with cough variant asthma following a URI should be treated with a standard antiasthmatic regimen of inhaled bronchodilators and inhaled corticosteroids as first-line therapy. 1

Understanding Cough Variant Asthma Post-URI

Cough variant asthma (CVA) often presents as a persistent, nonproductive cough following an upper respiratory infection. Unlike typical asthma, CVA may have minimal or no wheezing or dyspnea, making it challenging to diagnose. The cough can persist for weeks to months after other URI symptoms have resolved.

Diagnostic Considerations

Before initiating treatment, consider these key points:

• CVA is characterized by airway hyperresponsiveness that can be demonstrated through methacholine challenge testing
• A negative methacholine challenge test essentially excludes asthma from the differential diagnosis 1
• Post-viral cough may present similarly to CVA with transient bronchial hyperresponsiveness 1

Treatment Algorithm

First-Line Treatment:

1. Inhaled bronchodilators + inhaled corticosteroids
   • Partial improvement is often achieved after 1 week of inhaled bronchodilator therapy
   • Complete resolution may require up to 8 weeks of treatment with inhaled corticosteroids 1

For Inadequate Response:

1. Increase inhaled corticosteroid dose 1
2. Consider adding a leukotriene receptor antagonist 1
3. For severe or refractory cases:
   • Short course of oral corticosteroids (prednisone 30-40 mg daily for 1-2 weeks) 1
   • Follow with maintenance inhaled corticosteroids 1

Important Clinical Considerations

Potential Pitfalls:

• Inhaled steroid-induced cough: Some patients may develop cough from components in the inhaler (particularly beclomethasone dipropionate). Consider switching to a different inhaled steroid formulation if this occurs 1
• Inadequate diagnosis: Ensure proper diagnosis before escalating therapy, as other conditions like gastroesophageal reflux disease can mimic or coexist with CVA 1
• Premature discontinuation: Stopping therapy too soon may lead to symptom recurrence. Studies show that discontinuation of treatment causes worsening of symptoms and pulmonary function 2

Monitoring Response:

• Improvement in cough symptoms should begin within 1-2 weeks of appropriate therapy
• If cough persists beyond 8 weeks despite appropriate therapy, consider alternative diagnoses 1

Long-term Considerations:

• CVA may progress to classic asthma in some patients, particularly those with atopic features and sensitization to allergens like house dust mites 3
• Long-term inhaled corticosteroid therapy may be necessary to prevent progression to classic asthma 4
• Maintenance therapy with combination salmeterol/fluticasone provides better improvement in cough symptoms, pulmonary function, and airway inflammation compared to salmeterol alone 2

By following this evidence-based approach, most patients with cough variant asthma following a URI will experience significant improvement in their symptoms and quality of life.