What is the management plan for a patient with bronchiectasis shown on High-Resolution Computed Tomography (HRCT) scan, elevated eosinophils, and a history of potential mold exposure?

Management of Bronchiectasis Confirmed on HRCT with Elevated Eosinophils and Mold Exposure

In a patient with HRCT-confirmed bronchiectasis, elevated eosinophils, and potential mold exposure, you should first investigate for allergic bronchopulmonary aspergillosis (ABPA) and non-asthmatic eosinophilic bronchitis (NAEB), then initiate airway clearance techniques and consider inhaled corticosteroids if eosinophilic inflammation is confirmed. 1

Initial Diagnostic Workup

When bronchiectasis is confirmed on HRCT, a systematic evaluation for underlying causes is essential, as identifying treatable conditions can halt disease progression 1:

Priority Testing for This Clinical Scenario

• Allergic bronchopulmonary aspergillosis (ABPA) testing: Given the mold exposure history and elevated eosinophils, test for total IgE, Aspergillus-specific IgE and IgG, and skin prick testing for Aspergillus 1
• Sputum induction or bronchoscopy with bronchoalveolar lavage: To confirm eosinophilic airway inflammation (diagnostic for NAEB when eosinophils are present with normal spirometry and no airflow obstruction) 1
• Complete blood count with differential: Already showing elevated eosinophils, but quantify the degree 1
• Immunoglobulin levels (total IgG, IgA, IgM, IgE): Part of the minimal diagnostic bundle for all bronchiectasis patients 1
• Sputum culture: To identify chronic bacterial infection, particularly Pseudomonas aeruginosa, Haemophilus influenzae, or Aspergillus species 1

Additional Considerations

The isolation of Aspergillus from sputum suggests but does not confirm ABPA, as this organism can be isolated in other conditions 1. The combination of bronchiectasis, eosinophilia, and mold exposure creates a high pretest probability for ABPA, which requires specific corticosteroid therapy 1.

Treatment Strategy Based on Findings

If ABPA is Confirmed

• Avoidance of the causal allergen (mold) is the best treatment when identified 1
• Oral corticosteroids are the primary treatment for ABPA-related bronchiectasis 1
• Monitor for progression despite treatment, as some patients may require prolonged therapy 1

If NAEB is Confirmed (Eosinophilic Bronchitis Without Asthma)

• Inhaled corticosteroids (ICS) are first-line treatment for NAEB-related chronic cough and bronchiectasis 1
• If symptoms persist despite high-dose ICS, add oral corticosteroids 1
• Consider occupational causes given the mold exposure history 1

Important caveat: The 2006 ACCP guidelines recommend ICS for NAEB specifically, while more recent 2017 and 2025 European guidelines 1, 2 generally recommend against routine ICS use in idiopathic bronchiectasis due to lack of benefit and potential harm. However, eosinophilic airway inflammation represents a distinct phenotype where ICS may be beneficial 1, 3.

Core Bronchiectasis Management (Regardless of Etiology)

Airway Clearance

• Chest physiotherapy/airway clearance techniques should be initiated for all patients with bronchiectasis and mucus hypersecretion 1, 2
• Monitor for symptom improvement with these interventions 1

Bronchodilator Therapy

• If airflow obstruction or bronchial hyperreactivity is present on pulmonary function testing, bronchodilators may provide benefit 1

Antibiotic Management

• If chronic Pseudomonas aeruginosa infection is identified on sputum culture, consider long-term inhaled antipseudomonal antibiotics for patients at high risk of exacerbations 1, 2
• For idiopathic bronchiectasis without Pseudomonas, aerosolized antibiotics should not be used routinely 1
• Long-term macrolide therapy is strongly recommended for patients at high risk of exacerbations (typically ≥3 exacerbations per year) 1, 2

Clinical Pitfalls to Avoid

Do not assume all bronchiectasis with eosinophilia is asthma: Approximately 20% of bronchiectasis patients have eosinophilic inflammation, but only 7-46% have true comorbid asthma 3. NAEB and ABPA are distinct entities requiring different management 1.

Do not use rhDNase in non-CF bronchiectasis: This is contraindicated and associated with worse outcomes 1.

Do not delay investigation for underlying causes: In one study, 47% of bronchiectasis cases had identifiable causes, and 15% had diagnoses with important therapeutic implications 1. Early identification can prevent progression 1.

Recognize that bronchiectasis may be reversible in some cases: With appropriate treatment targeting the underlying cause, improvement or resolution can occur, particularly when diagnosed early 1.

Monitoring and Follow-up

• Pulmonary function testing to assess airflow obstruction and response to therapy 1
• Serial sputum cultures to monitor for chronic bacterial colonization, particularly Pseudomonas aeruginosa 1
• Repeat HRCT may be considered if clinical deterioration occurs or to assess treatment response in specific etiologies like ABPA 1

The presence of elevated eosinophils distinguishes this case from typical idiopathic bronchiectasis and mandates investigation for eosinophilic phenotypes (ABPA, NAEB) that respond to corticosteroid therapy rather than standard bronchiectasis management alone 1, 3.