Advancement of chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis(HP) is an immune-mediated interstitial lung disease in response to inhalation of various antigenic organic substances.Chronic hypersensitivity pneumonitis(CHP) may be caused by exposure to low concentration of antigen for a long time or the recurrences of acute or subacute HP.In recent years, more and more microbacteria, proteins and organic particules can lead to the development of HP, however the mechanism is still unclear.As absent of definite exposure history, patients with CHP were usually recognized and treated difficultly.The review will be present the updated researches of pathogenesis, clinical diagnosis and treatment of CHP. Key words: Hypersensitivity pneumonitis, chronic; Pulmonary fibrosis