OVERVIEW
ABPA is an allergic reaction to the fungus Aspergillus, commonly found in the environment. It occurs in individuals with asthma or cystic fibrosis when the immune system overreacts to the fungus, causing inflammation and lung damage if untreated.
What is ABPA (Allergic Bronchopulmonary Aspergillosis)?
Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitive immune response to Aspergillus fumigatus, a common environmental fungus. It primarily affects individuals with asthma or cystic fibrosis, where the immune system overreacts to the fungus, causing inflammation, mucus production, and, over time, damage to the lungs. If left untreated, ABPA can lead to chronic lung conditions such as bronchiectasis or fibrosis.
Symptoms
- Persistent coughing, often producing thick mucus plugs or brownish sputum.
- Shortness of breath, wheezing, and chest tightness, similar to severe asthma symptoms.
- Fever and fatigue, particularly during flare-ups.
- Recurrent lung infections or worsening asthma despite standard treatments.
- Blood-streaked sputum in some cases due to inflammation or irritation.
Causes
ABPA is caused by an allergic reaction to Aspergillus fumigatus. This fungus is commonly found in soil, decaying vegetation, and even indoor environments. In susceptible individuals, such as those with asthma or cystic fibrosis, the immune system mistakenly identifies the fungus as a harmful invader, triggering a strong inflammatory response. This leads to excessive mucus production, airway obstruction, and lung tissue damage over time.
Diagnosis
Diagnosing ABPA involves a combination of clinical evaluation, laboratory tests, and imaging:
- Clinical History: Symptoms of asthma or cystic fibrosis that worsen despite treatment.
- Blood Tests: Elevated levels of total IgE, specific IgE, and IgG antibodies against Aspergillus fumigatus.
- Skin Tests: Positive reaction to an Aspergillus antigen, indicating hypersensitivity.
- Imaging Studies: Chest X-rays or CT scans revealing central bronchiectasis, mucus plugging, or other lung abnormalities.
- Sputum Culture: Detection of Aspergillus in respiratory secretions to confirm fungal presence.