What is ABPA?
Allergic bronchopulmonary aspergillosis, or ABPA, is an exaggerated allergic reaction to Aspergillus fumigatus, a mould that is present in the air almost everywhere. In most people, inhaled spores are cleared harmlessly. In ABPA the fungus grows within the mucus of the airways and triggers intense allergic inflammation, producing thick mucus plugs and, over time, damage and widening of the airways (bronchiectasis).
ABPA occurs almost entirely in people with asthma or cystic fibrosis. It is uncommon overall but is an important and under-recognised cause of poorly controlled asthma, and India is thought to carry a large share of the world's cases.
Early diagnosis matters, because treatment can prevent permanent lung damage.
Symptoms of ABPA
- Poorly controlled asthma: frequent attacks, increasing wheeze and need for oral steroids despite regular inhalers.
- Cough with thick mucus: often with brown or black plugs or casts coughed up.
- Coughing up blood: usually small amounts.
- Fever, tiredness and weight loss during flares.
- Chest pain or breathlessness when mucus plugs block an airway and part of a lung collapses.
Some patients have few symptoms, and the condition is first suspected from an abnormal chest X-ray or a very high blood IgE level.
Causes and risk factors
Aspergillus spores are found in soil, decaying vegetation, dust, damp buildings and stored grain. ABPA develops not because of unusually heavy exposure but because of the way certain people's airways and immune systems respond to the fungus. Risk factors include long-standing asthma, cystic fibrosis, a strongly allergic (atopic) tendency and genetic factors that affect airway defences.
ABPA is not an infection that spreads between people, and it is different from invasive aspergillosis, which affects people with severely weakened immunity.
How ABPA is diagnosed
Every patient with difficult asthma should be screened for sensitisation to Aspergillus. In India, the shifting shadows on X-ray and cough with blood-stained sputum frequently lead to repeated treatment for tuberculosis, so ABPA should be considered when sputum tests for tuberculosis are negative in a patient with asthma.
| Test | What it shows |
|---|---|
| Aspergillus-specific IgE or skin test | Allergic sensitisation to Aspergillus, the essential first screen |
| Total serum IgE | A markedly raised level supports ABPA and is used to track response to treatment |
| Aspergillus-specific IgG | Ongoing immune response to the fungus |
| Blood eosinophil count | Allergic-type inflammation |
| High-resolution CT of the chest | Central bronchiectasis, mucus plugging and, characteristically, high-density mucus |
| Spirometry | Degree of airflow obstruction and response to treatment |
Diagnosis follows internationally agreed criteria that combine these results. Bronchoscopy is sometimes used to remove obstructing mucus plugs or to exclude other conditions.
Treatment of ABPA
Treating the acute stage
The aim is to suppress the allergic inflammation and reduce the fungal burden. Oral corticosteroids given as a tapering course are effective. Oral antifungal treatment, most often itraconazole, is an alternative or an addition, and helps reduce steroid requirements. The choice depends on the severity, the presence of mucus plugging and the patient's risk of steroid side effects.
Preventing relapse
Response is checked with symptoms, total IgE levels and imaging. Relapses are treated early to prevent progressive bronchiectasis. In patients with repeated relapses or steroid dependence, biologic drugs targeting IgE or interleukin-5 pathways are used in selected cases.
Ongoing asthma care
Regular inhaled therapy, correct inhaler technique, airway clearance for those with bronchiectasis, and reducing exposure to damp and mouldy environments all help maintain control.
Outlook and follow-up
Most patients respond well to treatment, and asthma control usually improves considerably. ABPA is, however, a long-term condition with a tendency to relapse, so periodic measurement of IgE and lung function is recommended even when the patient feels well. Patients diagnosed after extensive bronchiectasis or lung scarring have already developed may have persistent symptoms, which is why early recognition is important.
When to seek urgent care
Seek emergency attention for a severe asthma attack not relieved by the reliever inhaler, breathlessness at rest, coughing up more than a small amount of blood, sudden chest pain, or blue lips or fingertips. A flare with high fever and increasing breathlessness also warrants prompt review.
Frequently asked questions
Is ABPA a fungal infection?
ABPA is mainly an allergic reaction to the Aspergillus fungus growing in the airway mucus, rather than an invasive infection. That is why steroids, which calm the allergic reaction, are a key part of treatment, often alongside antifungal tablets.
Why was I treated for tuberculosis before ABPA was found?
ABPA can cause shadows on the chest X-ray, cough and blood in the sputum, which look similar to tuberculosis. Tuberculosis is common in India, so it is often suspected first. Negative tuberculosis tests in a person with asthma should prompt testing for ABPA.
Can ABPA be cured?
Many patients achieve long-lasting remission, but ABPA can relapse years later. Regular follow-up with IgE levels and lung function helps catch relapse early.
Can I avoid Aspergillus completely?
Complete avoidance is not possible because the spores are everywhere. Reducing exposure to damp, mouldy rooms, compost, construction dust and stored grain is sensible but does not replace treatment.
Will I need steroids for life?
Most patients need steroids for a limited period during flares. Antifungal tablets and, in selected cases, biologic injections help reduce or stop long-term steroid use.
Does ABPA cause permanent lung damage?
Untreated or repeatedly relapsing ABPA can cause bronchiectasis and scarring. Early diagnosis and treatment greatly reduce this risk.
Related conditions and procedures
Consult Dr. Gogineni Ratnakara Rao
Apollo Hospitals, Financial District: Monday to Saturday, 8:30 AM to 5:00 PM. Anything in Lung Clinic, Chanda Nagar: Monday to Saturday (Thursday closed), 6:00 PM to 9:00 PM.