Which of the following are true regarding extrinsic allergic alveolitis?
a) Ground glass attenuation with areas of lobular sparing is typical on HRCT
b) The precipitin test is usually negative
c) Pleural effusions arc common
d) Bronchiectasis occurs in chronic disease
e) Interstitial fibrosis usually affects the lower lobes
For extrinsic allergic alveolitis (also known as hypersensitivity pneumonitis), the correct statements are:
a) Ground glass attenuation with areas of lobular sparing is typical on HRCT — Ground glass opacities with or without lobular sparing are commonly seen in HRCT scans of patients with extrinsic allergic alveolitis.
d) **Bronchiectasis occurs in chronic disease** — In chronic cases of extrinsic allergic alveolitis, bronchiectasis can develop as a complication.
The other statements are generally not true for extrinsic allergic alveolitis:
b) The precipitin test is usually positive, as it detects specific antibodies against inhaled antigens.
c) Pleural effusions are not common in extrinsic allergic alveolitis; they are more typical in other conditions like infections or congestive heart failure.
e) Interstitial fibrosis usually affects the upper lobes in extrinsic allergic alveolitis, not the lower lobes.