Allergic bronchopulmonary aspergillosis (ABPA) is at one end of the spectrum of disease caused by pulmonary aspergillosis and can be classified as an eosinophilic lung disease.

It is seen is almost only encountered in patients with longstanding asthma, and only occasionally in patients with cystic fibrosis.  Only rarely does it appear in patients with no other identifiable pulmonary illness. 

CT findings include:

• centrilobular nodules representing dilated and opacified bronchioles
• bronchiectasis
  • central, upper lobe saccular bronchiectasis involving segmental and subsegmental bronchi is characteristic
  • mucoid impaction results in a bronchocoele, the finger in glove sign 
  • this may give a Y, V or toothpaste-like like configuration
  • centrilobular nodular opacities.
  • high attenuation (calcification) in impacted mucus in ~30% 
  • bronchial wall thickening: common
• chronic disease may progress to pulmonary fibrosis, predominantly in upper lobe
• cavitation: 10%

Treatment of ABPA is difficult due to the ubiquity of Aspergillus in the environment.