Possibilities of computed tomography of lungs in diagnosis and differential diagnosis of hypersensitive pneumonitis (literature review)

Hypersensitive pneumonitis (HP) is a disease that occurs in inhalational exposure of environmental antigens and develops an immune-mediated inflammatory reaction in terminal bronchioles, alveoli and pulmonary interstitium. Classification of HP has changed many times, nevertheless emphasis on the selection of fibrotic and non-fibrotic HP phenotypes is made in recent years. Despite the modern achievements in high-resolution computed tomography (HRCT) of the lungs, significant difficulties in differential diagnosis of fibrotic HP with other pulmonary fibrosis variants, especially with idiopathic pulmonary fibrosis, remain. The review describes the main symptoms of non-fibrotic and fibrotic HP and their differences from other interstitial lung diseases, as well as the correlation of HRCT symptoms with histological manifestations of the disease.