Allergic Bronchopulmonary Aspergillosis (ABPA) Without Asthma: A Hidden Reality

Most people – including many doctors – associate Allergic Bronchopulmonary Aspergillosis (ABPA) almost exclusively with asthma or cystic fibrosis. In fact, the current diagnostic criteria for ABPA often assume the presence of asthma as a prerequisite. But what happens when a patient has all the features of ABPA… without ever having had asthma?

This article explores the possibility – and growing recognition – of ABPA without asthma.

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🔍 What Is ABPA?

ABPA is an allergic (hypersensitivity) reaction to the fungus Aspergillus fumigatus, which can colonise the lungs and cause:

• Severe allergic inflammation

• Damage to lung tissue (bronchiectasis)

• High levels of IgE (often >1000 IU/mL)

• Positive skin tests or blood tests for Aspergillus

Traditionally, ABPA is diagnosed in people with asthma or cystic fibrosis, where the airways are already vulnerable.

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❗But Can ABPA Occur Without Asthma?

Yes. Though uncommon, there are confirmed cases where ABPA occurs in people who:

• Do not have asthma

• Have no wheeze, breathlessness or variability in symptoms

• Show no reversibility on a bronchodilator test

• May not respond to inhaled corticosteroids

This presentation is now increasingly recognised – particularly:

• After viral infections like COVID-19

• In people exposed to environmental moulds

• In those with no personal or family history of asthma

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🧪 Diagnostic Clues

Patients with ABPA but no asthma typically still show:

• Very high total IgE levels

• Positive Aspergillus-specific IgE and IgG

• Radiological changes like central bronchiectasis

• Sometimes eosinophilia in blood

But they do not show:

• Classic asthma symptoms (e.g. wheeze, reversible breathlessness)

• Improvement with bronchodilators

• Variable peak flow readings

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🧬 How Might This Happen?

There are a few theories:

• Some people have a strong allergic immune response (IgE-driven) to Aspergillus alone, even without underlying asthma

• COVID-19 and other infections may prime the immune system or damage airways enough to allow fungal colonisation

• Not all bronchial hypersensitivity is asthma — the airway inflammation in ABPA is unique and not always “asthmatic” in pattern

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✅ What Tests Can Help Confirm or Rule Out Asthma?

For patients who have ABPA but no clear asthma symptoms:

• Bronchodilator reversibility test → May be negative

• Methacholine or histamine challenge test → Gold standard for confirming asthma

• FeNO test → Measures eosinophilic airway inflammation (may be high in both ABPA and asthma)

• Peak flow monitoring → Often stable in ABPA without asthma

These tests can help clarify the diagnosis and prevent mislabeling patients as asthmatic when they are not.

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🧭 Why Does It Matter?

Correct diagnosis matters because:

• Not all ABPA patients benefit from inhaled corticosteroids or asthma drugs

• Treatment should be tailored — e.g. antifungals and oral steroids for ABPA, but not unnecessary asthma medications

• Misdiagnosis may delay the right treatment and overburden patients

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🩺 A Call to Clinicians

If a patient has high IgE, bronchiectasis, and strong Aspergillus sensitisation — but no clinical asthma — consider ABPA without asthma.

Request confirmatory tests before labeling someone asthmatic for life. In these rare cases, asthma criteria do not fully apply — but the patient still needs support for ABPA.

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🧾 Summary

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🙋 What Can Patients Do?

If you’ve been diagnosed with ABPA but don’t believe you have asthma:

• Ask your doctor about further testing to confirm or rule out asthma

• Keep a record of your symptoms, peak flow (if used), and medication response

• Discuss your IgE levels, CT scan results, and whether other diagnoses (e.g. chronic pulmonary aspergillosis) might apply

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