Allergic Broncho-Pulmonary Aspergillosis (ABPA)

Allergic Bronchopulmonary Aspergillosis (ABPA)

Overview | Symptoms | Causes | Diagnosis | Treatment | Living with ABPA | What’s New | Further Information

🫁 Overview

Allergic Bronchopulmonary Aspergillosis (ABPA) is a lung condition caused by an exaggerated allergic reaction to the fungus Aspergillus fumigatus.
This fungus is common in the environment — found in soil, compost, and decaying leaves — and most people breathe in its spores every day without harm.

In people with asthma, bronchiectasis, or cystic fibrosis, however, the immune system can over-react to these spores, causing inflammation, mucus plugging, and damage to the airways.
If untreated, ABPA can gradually lead to permanent changes in the lungs (bronchiectasis) and loss of lung function.

⚠️ Symptoms

Symptoms often overlap with those of asthma or bronchiectasis and may develop slowly.
Common signs include:

  • Worsening asthma symptoms (cough, wheeze, chest tightness)

  • Thick or brown-coloured mucus or mucus plugs

  • Persistent chest infections that don’t clear

  • Shortness of breath or breathlessness

  • Coughing up blood (haemoptysis)

  • Fatigue, malaise, or weight loss

Symptoms usually fluctuate over time, with “flare-ups” (exacerbations) followed by quieter periods.

🧬 Causes and Risk Factors

ABPA occurs when the body’s immune system over-reacts to the presence of Aspergillus spores in the airways.
Rather than clearing the spores, the immune system triggers inflammation, mucus overproduction, and swelling that can block airways.

You are more likely to develop ABPA if you have:

  • Asthma

  • Cystic fibrosis

  • Bronchiectasis or chronic mucus build-up

  • Repeated chest infections

  • Long-term steroid or immune-modulating medication use

🩺 Diagnosis

Diagnosing ABPA requires several tests and is best done by a specialist team, as symptoms can mimic other lung diseases.

Typical investigations include:

  • Blood tests to check:

    • Total Immunoglobulin E (IgE) – an allergy marker

    • Specific IgE and IgG antibodies against Aspergillus fumigatus

    • Eosinophil count (a type of white blood cell linked to allergic inflammation)

  • CT scan or X-ray – to identify bronchiectasis, mucus plugging, or other lung changes

  • Sputum tests – to look for Aspergillus in mucus samples

🆕 What’s New in 2024/25: Updated Diagnostic Criteria

The International Society for Human and Animal Mycology (ISHAM) updated its global guidance in 2024–25, refining how ABPA is diagnosed:

  • Total IgE threshold lowered to ≥ 500 IU/mL (previously often > 1000 IU/mL)

  • Blood eosinophil count ≥ 500 cells/µL is now part of the diagnostic standard

  • Imaging and immunological evidence (Aspergillus-specific IgE or IgG) remain essential

  • The goal is earlier detection and treatment — before significant lung damage occurs

These new thresholds help identify ABPA sooner, especially in people with asthma whose symptoms are not fully controlled.

(Reference: Agarwal et al., European Respiratory Journal 2024, 63(4):2400061)

💊 Treatment and Management

Treatment aims to control inflammation, reduce allergic response, and prevent long-term lung damage.

  1. Corticosteroids

    • Usually the first-line treatment (e.g., prednisolone or methylprednisolone).

    • Help reduce airway inflammation and improve breathing.

    • Doses are tapered gradually to the lowest effective level.

  2. Antifungal Therapy

    • Drugs like itraconazole, voriconazole, or posaconazole help reduce fungal load and allergic stimulation.

    • Useful for steroid-dependent or relapsing ABPA.

    • Requires regular blood tests to monitor absorption and liver function.

  3. Biologic Treatments (Newer Option)

    • Biologics such as omalizumab (anti-IgE), mepolizumab and benralizumab (anti-IL-5), or dupilumab (anti-IL-4Rα) can target key immune pathways.

    • Particularly useful for patients who relapse frequently or cannot tolerate steroids.

    • Recent reviews suggest dupilumab may offer superior control in some cases.

    • These are now recognised in guideline updates as valid options for treatment-resistant ABPA.

  4. Supportive Care

    • Regular airway clearance techniques if you have bronchiectasis

    • Optimised inhaler therapy for asthma

    • Vaccinations (e.g., flu, pneumonia)

    • Avoiding damp environments and compost exposure

💚 Living with ABPA

ABPA is a chronic condition, but with good management most people can live well and stay active.

  • Attend regular follow-up appointments with your respiratory or infectious disease specialist

  • Track symptoms and flare-ups; let your team know about new or worsening breathlessness, cough, or blood in sputum

  • Keep up-to-date with blood tests and scans as recommended

  • Be consistent with inhaler use and airway clearance

  • Maintain healthy lifestyle habits (exercise, nutrition, avoiding smoking)

Specialist centres like the National Aspergillosis Centre (NAC) in Manchester offer diagnostic reviews, treatment advice, and patient support.

📚 Further Information and Support

 

** Last Reviewed Oct 2025