How should recurrence of allergic bronchopulmonary aspergillosis (ABPA) be diagnosed and managed?

Management of ABPA Recurrence

For recurrent ABPA exacerbations (≥2 episodes in the last 1-2 years), use combination therapy with oral prednisolone plus itraconazole rather than monotherapy. 1

Diagnosing ABPA Recurrence

ABPA exacerbations are diagnosed by three key features occurring together over ≥2 weeks: 1

• Sustained worsening of respiratory symptoms (increased cough, wheezing, dyspnea, or sputum production) 1
• New pulmonary infiltrates on chest imaging (chest radiograph or CT) 1
• Serum total IgE elevation ≥50% above the patient's "new baseline" (the IgE level during clinical stability after prior treatment) 1

Critical Distinction from Other Exacerbations

You must differentiate ABPA exacerbations from two other common causes of worsening in these patients: 1

• Asthma exacerbations: No IgE elevation ≥50% and no new infiltrates on imaging—treat with short-course oral glucocorticoids alone 1
• Bronchiectasis (infective) exacerbations: Clinical worsening without IgE elevation ≥50%, often with positive sputum bacterial cultures—treat with antibiotics 1

Common pitfall: Occasionally these exacerbation types overlap in a single patient, requiring treatment of multiple conditions simultaneously. 1

Treatment Algorithm for ABPA Recurrence

First Exacerbation or Infrequent Exacerbations (<2 in 1-2 years)

Treat exactly as newly diagnosed acute ABPA with monotherapy: 1

• Oral prednisolone (0.5 mg/kg/day for 2 weeks, then taper over 8-12 weeks) OR 1
• Oral itraconazole (200 mg twice daily for 6 months with therapeutic drug monitoring) 1

Recurrent Exacerbations (≥2 in the Last 1-2 Years)

Use combination therapy with oral prednisolone PLUS oral itraconazole, especially in patients with extensive bronchiectasis. 1 This represents a 71.4% consensus recommendation from the 2024 ISHAM guidelines, reflecting expert opinion that recurrent disease requires more aggressive dual therapy to prevent progressive bronchiectasis and preserve lung function. 1

The rationale is that recurrent exacerbations indicate inadequate disease control with monotherapy and signal higher risk for permanent structural lung damage. 1

Therapies NOT Recommended for ABPA Exacerbations

• Biological agents: Not recommended for acute exacerbations (94.3% consensus against) 1
• Nebulized amphotericin B: Poor efficacy, 100% consensus against use 1
• High-dose inhaled corticosteroids: Should not be used as primary therapy (100% consensus) 1

Refractory Cases

For ABPA exacerbations that fail to respond to oral glucocorticoids, pulse doses of intravenous methylprednisolone have been used, though this is based on limited evidence. 1

Monitoring Treatment Response

Assess response at 8-12 weeks after treatment initiation using three parameters: 1

Clinical Symptoms

Use a semiquantitative Likert scale for routine care: 1

• No improvement or worsening
• Mild improvement (<25% from baseline)
• Moderate improvement (25-50% from baseline)
• Significant improvement (>50% from baseline)

Good response requires ≥50% symptom improvement. 1

Serum Total IgE

Good response requires ≥20% reduction from pre-treatment levels. 1 Monitor this closely as it is the most objective biomarker of treatment response.

Important caveat: Aspergillus-specific IgE and IgG levels do not consistently fall with treatment and should not be used to assess response. 1

Chest Imaging

Look for resolution of infiltrates and mucus plugging on chest radiograph or CT. 1

Additional Monitoring Parameters

• Spirometry: A forced expiratory volume in 1 second (FEV₁) improvement of ≥158 mL represents the minimal clinically important difference for ABPA treatment response 1
• Blood eosinophil count: Not validated for assessing treatment response 1

Prevention of Future Recurrences

After achieving remission, approximately 50% of ABPA patients experience exacerbations, making prevention strategies critical. 1 The key is recognizing patients at high risk for recurrence (those with ≥2 exacerbations in 1-2 years) and treating them more aggressively with combination therapy from the outset. 1

Monitoring during remission: Follow patients with periodic assessment of symptoms, serum total IgE, and chest imaging to detect early recurrence before irreversible bronchiectasis develops. 1