Can You Have ABPA with a Normal CT Scan? Yes — Here’s Why

If you’ve been diagnosed with ABPA (Allergic Bronchopulmonary Aspergillosis) but your HRCT (High-Resolution CT) scan looks normal, you may feel confused — or even wonder if the diagnosis is correct. After all, ABPA is often associated with visible lung damage on scans, right?

The answer is: yes, you can have ABPA with a normal scan — and it’s more common than many people realise.

Let’s break it down.

🧠 What Is ABPA?

ABPA is a condition in which the immune system overreacts to a common environmental fungus, Aspergillus fumigatus. This overreaction leads to:

• Inflammation in the lungs

• Wheezing and breathlessness

• Cough with mucus

• And, in some cases, damage to the airways over time

It often occurs in people who already have asthma or cystic fibrosis.

🧪 How Is ABPA Diagnosed?

ABPA is not diagnosed by just one test. It’s based on a combination of findings, including:

• High total IgE (an allergy antibody)

• Specific IgE to Aspergillus fumigatus (proves sensitivity to the fungus)

• Blood eosinophilia (a type of allergy-related white blood cell)

• Clinical symptoms (like wheezing, cough, or mucus plugging)

• Chest imaging — typically an HRCT scan

But here’s the key point: you don’t need visible lung damage on a scan to be diagnosed with ABPA.

📊 What If Your CT Scan Looks Normal?

This is actually quite common, especially in the early stages of ABPA.

• No visible lung damage may simply mean the condition has been caught early — before structural changes (like bronchiectasis or mucus plugging) have developed.

• Some people may go through milder or intermittent flares without developing long-term damage.

• In certain cases, lung damage may be subtle or not easily seen on the scan, especially if inflammation is mild or temporary.

🆕 What Do the Latest Guidelines Say?

The 2024 update to the ISHAM diagnostic criteria for ABPA (by the International Society for Human and Animal Mycology) recognises that some patients may have ABPA even if their CT scan appears normal.

This form is sometimes called:

• ABPA-S, where “S” stands for serologic (diagnosis is based on blood tests)

• It means the allergic reaction is present in the body, even if lung damage hasn’t occurred yet

This updated understanding helps doctors diagnose ABPA earlier, so treatment can begin before lasting damage happens.

💬 What Should You Do If You’re in This Situation?

If you’ve been diagnosed with ABPA but your scan is normal:

• Don’t dismiss the diagnosis — it could be accurate and important.

• Ask your doctor whether your diagnosis fits the 2024 ISHAM criteria.

• Track your symptoms, IgE levels, and any breathing changes over time.

• Talk to your healthcare provider about treatment options, which may include:

  • Steroids to reduce inflammation

  • Antifungal medications to reduce fungal exposure in the lungs

  • Biologic treatments if other options aren’t suitable

✅ Key Points to Remember

• Yes, ABPA can occur with a normal CT scan.

• Diagnosis is based on immune response and symptoms, not just imaging.

• Early detection — before damage shows up on scans — is a good thing.

• Updated guidelines now recognise this form of ABPA as valid and treatable.

If you’re feeling uncertain about your diagnosis, don’t hesitate to ask your doctor for a clear explanation — or consider a second opinion from a respiratory specialist with experience in fungal allergy and ABPA.

The earlier ABPA is identified and treated, the better the chances of keeping your lungs healthy and symptoms under control.