ABPA is a disease state induced by arthus reaction to colonizing
aspergillus in the bronchi in patients with bronchial asthma.
Clinical Picture
- ABPA should be suspected whenever asthma is refractory and is
associated with fever, cough and black or grey sputum.
- Chest x-ray often reveals evanescent pulmonary infiltrates.
- Marked eosinophilia and elevated IgE are noted.
Pathophysiology
- Aspergillus colonizes in the bronchi in asthmatics because of thick secretions. A
precipitating antibody is produced. A type III immunological reaction
follows. Complement is activated. An inflammatory response occurs with
damage to the bronchial wall and the bronchi get plugged with secretion. Segmental
infiltrates and atelectasis follows.
Diagnosis
- Aspergillus precipitating antibody is detected in serum.
- IgE levels and eosinophiles are elevated.
- Central bronchiectasis can be demonstrated by CT scan.
Treatment
- ABPA responds to systemic steroids.
- Dose and duration of steroids can be adjusted by following serum IgE levels.