Advances in diagnosis and treatment of chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by repeated inhalation of organic dust antigen.Nowadays, HP is been mainly divided into two categories, acute hypersensitivity pneumonitis and chronic hypersensitiviry penumonitis (CHP). The radiological features of CHP are similar to those of idiopathic pulmonary fibrosis, chronic sarcoidosis and idiopathic pulmonary hemosiderosis.This article reviews the etiology, clinical manifestation, diagnosis and treatment of CHP. Key words: Alveolitis, extrinsic allergic; Diagnosis; Diagnosis, differential