Definition and epidemiology
Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to Aspergillus fumigatus colonising the airways, producing recurrent wheeze, fleeting pulmonary infiltrates, bronchiectasis and progressive lung damage. It is overwhelmingly a complication of two predisposing conditions: asthma and cystic fibrosis (CF). Estimates suggest ABPA complicates roughly 1–2% of asthma and a higher fraction of CF, though figures vary by case definition and screening intensity. When the causative mould is a non-fumigatus species or another fungus, the broader term allergic bronchopulmonary mycosis (ABPM) is used.
Clinical features
Suspect ABPA in a child with poorly controlled or steroid-dependent asthma, or in CF with unexplained clinical decline. Typical features are recurrent wheeze, low-grade fever, malaise, productive cough with brownish mucus plugs, occasional haemoptysis and migratory infiltrates on imaging. Examination may reveal wheeze and, in advanced disease, signs of bronchiectasis. In CF the picture overlaps heavily with baseline lung disease, making diagnosis difficult and warranting a lower threshold for serological screening.
Diagnosis
Diagnosis rests on a combination of predisposing condition, immunological evidence of Aspergillus sensitisation, and supportive radiology. The historic Rosenberg-Patterson criteria (1977) were highly specific but insensitive. The ISHAM working group criteria (2013, revised 2024) anchor diagnosis on: a predisposing condition (asthma or CF); obligatory immunological criteria — elevated A. fumigatus-specific IgE and a positive type-I skin test or specific IgE; and raised total serum IgE; plus at least two of Aspergillus-precipitins/specific IgG, eosinophilia and consistent radiology (fleeting infiltrates, mucus plugging, central bronchiectasis). The 2024 revision lowered the total-IgE threshold and gave microbiological findings greater weight, and for the first time set distinct ABPA and ABPM criteria. Staging spans serologic ABPA, ABPA with bronchiectasis, and end-stage fibrotic disease.
See the full criteria: Allergic Bronchopulmonary Aspergillosis
Red flags
- Massive or recurrent haemoptysis — consider a mycetoma or vascular erosion
- Lobar collapse from mucus impaction needing bronchoscopic clearance
- Rapid radiological progression or new fibrosis/honeycombing (end-stage disease)
- In CF, an unexplained step-down in lung function or weight despite adherence
- Features suggesting invasive aspergillosis in an immunocompromised child
Management overview
The goals are to suppress the immune/inflammatory response, reduce fungal burden and prevent irreversible lung damage. Systemic corticosteroids are the mainstay for acute exacerbations and active disease, tapered against symptoms, total IgE trend and imaging. Oral antifungal agents (triazole class) are added to reduce fungal load and act as steroid-sparing therapy, with attention to drug interactions and hepatotoxicity monitoring. Anti-IgE and anti-IL-5 biologic agents are increasingly used in difficult, steroid-dependent or relapsing disease. Optimise the underlying asthma or CF, ensure airway clearance, and monitor serial total IgE as the most useful marker of activity and relapse. Multidisciplinary CF-team involvement is essential when ABPA complicates cystic fibrosis.
References
- Agarwal R, et al. Revised ISHAM-ABPA/ABPM clinical practice guidelines. Chinese Medical Journal, 2025.
- Agarwal R, et al. ISHAM working group ABPA criteria. Clinical & Experimental Allergy, 2013.
- Rosenberg M, Patterson R, et al. Annals of Internal Medicine, 1977.
- Nelson Textbook of Pediatrics, 21st ed.
Decision support for qualified clinicians only — verify against current primary guidelines and your clinical judgement.