What is the treatment for nonasthmatic eosinophilic bronchitis?

Treatment for Nonasthmatic Eosinophilic Bronchitis

Inhaled corticosteroids are the first-line treatment for nonasthmatic eosinophilic bronchitis (NAEB), with allergen or occupational sensitizer avoidance as the primary approach when a specific trigger is identified. 1

Diagnostic Approach

Before initiating treatment, confirm the diagnosis with:

• Normal chest radiograph
• Normal spirometry
• No evidence of variable airflow obstruction or airway hyperresponsiveness
• Presence of airway eosinophilia (>3% in sputum) confirmed by induced sputum or bronchial wash fluid 1

Treatment Algorithm

First-line Treatment:

1. Identify and avoid triggers

   • Evaluate for occupational exposures or allergens 1
   • Complete avoidance is the best treatment when a causal allergen or occupational sensitizer is identified 1

2. Inhaled corticosteroids (ICS)

   • Start with medium-dose ICS (e.g., budesonide 400 μg twice daily) 1
   • Continue for at least 4 weeks initially 1
   • Monitor response through symptom improvement and reduction in sputum eosinophil count

For Persistent or Severe Symptoms:

1. Escalate to high-dose ICS if inadequate response to medium-dose therapy 1

2. Add oral corticosteroids if symptoms remain persistently troublesome or eosinophilic airway inflammation progresses despite high-dose ICS 1

   • Consider prednisolone 30 mg/day for 2 weeks as a therapeutic trial 1

Treatment Considerations

Efficacy and Response

• Inhaled corticosteroids improve both symptoms and reduce sputum eosinophil counts 1
• Capsaicin cough sensitivity (which is increased in NAEB) improves toward normal after treatment with budesonide 1
• Treatment response correlates with reduction in sputum eosinophil count 1

Treatment Duration

• Optimal duration remains unclear 1, 2
• Consider long-term therapy as complete resolution is rare (only 3% of patients) 3
• Longer treatment duration is associated with lower relapse rates 2

Disease Course and Monitoring

• NAEB is rarely self-limiting; most patients (66%) have persistent symptoms and/or ongoing airway inflammation 3
• Regular monitoring of symptoms and sputum eosinophil counts is recommended
• Monitor for disease progression:
  • 9% of patients develop asthma 3
  • 16% develop fixed airflow obstruction 3

Potential Pitfalls

1. Failure to identify occupational causes

   • Always consider occupational exposures as potential triggers 1
   • Occupational history is essential in evaluation

2. Inadequate treatment duration

   • Short-term treatment may lead to relapse 2
   • Consider maintenance therapy for persistent cases

3. Overlooking disease progression

   • Female gender, smoking, and prolonged eosinophilic airway inflammation are risk factors for more rapid decline in FEV₁ 3
   • Regular spirometry monitoring is important

4. Misdiagnosis

   • Ensure proper differentiation from cough variant asthma, which requires different management approaches 4
   • Confirm absence of variable airflow obstruction and airway hyperresponsiveness

While the evidence for inhaled corticosteroids is substantial, there are still gaps in knowledge regarding optimal dosing, specific corticosteroid choice, and treatment duration. The treatment approach should focus on controlling symptoms and reducing eosinophilic inflammation to prevent disease progression and improve quality of life.