What is the management approach for eosinophilic bronchitis?

Management of Eosinophilic Bronchitis

Inhaled corticosteroids are the first-line treatment for eosinophilic bronchitis and should be administered for at least 2-3 months to reduce relapse rates. 1, 2

Diagnosis

Eosinophilic bronchitis is characterized by:

• Chronic cough
• Sputum eosinophilia (>3% eosinophils)
• Normal spirometry
• No evidence of variable airflow obstruction
• No airway hyperresponsiveness (negative methacholine challenge test)

The diagnosis is confirmed by:

1. Demonstration of airway eosinophilia through sputum induction or bronchoscopy
2. Improvement in cough following corticosteroid therapy 1

Treatment Algorithm

First-line Treatment

• Inhaled corticosteroids (e.g., budesonide 400 μg twice daily) 1, 3
  • Continue for at least 2-3 months to minimize relapse risk 2
  • Shorter treatment durations (1 month) are associated with significantly higher relapse rates (41.9%) compared to longer treatment durations (12% relapse with 3-month treatment) 2

For Inadequate Response

• Increase inhaled corticosteroid dose
• Consider adding a leukotriene receptor antagonist 1
• For severe or refractory cases, a short course of oral corticosteroids may be necessary 1, 4

Occupational Considerations

• Always evaluate for potential occupational exposures as triggers 1, 5
• Implement avoidance strategies when eosinophilic inflammation is due to occupational exposure or inhaled allergen 1

Monitoring and Follow-up

• Monitor sputum eosinophil counts to assess treatment response 3
• Successful treatment should result in:
  1. Reduction in cough severity
  2. Decrease in sputum eosinophil count (typically from ~16% to <2%) 3

Treatment Duration and Maintenance

• Initial treatment should continue for at least 2-3 months 2
• After symptom resolution, consider gradual step-down of inhaled corticosteroid dose
• Some patients may require long-term maintenance therapy to prevent relapse 1
• The optimal duration of long-term therapy remains unclear, but treatment decisions should be guided by symptom control and sputum eosinophil counts 1

Pitfalls and Caveats

• Eosinophilic bronchitis accounts for approximately 13% of chronic cough cases and 30% of those requiring sputum induction for diagnosis 1, 3
• It is often misdiagnosed as cough-variant asthma, but differs by the absence of airway hyperresponsiveness 6
• Failure to improve with inhaled corticosteroids should prompt reconsideration of the diagnosis 1
• While most cases have a benign course, some patients may develop persistent airflow obstruction over time 6
• In patients with COPD who have eosinophilic inflammation, treatment with inhaled corticosteroids can significantly reduce severe exacerbations 7

By following this structured approach to the management of eosinophilic bronchitis, clinicians can effectively control symptoms, reduce inflammation, and minimize the risk of relapse in affected patients.