title: Chronic hypersensitivity pneumonitis.
abstract: Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of environmental antigens. Chronic HP may mimic other fibrotic lung diseases, such as idiopathic pulmonary fibrosis. Recognition of the antigen is important for diagnosis; avoidance of further exposure is critical for treatment. Fibrosis on biopsy or high-resolution computed tomography is a predictor of increased mortality. Additional research is needed to understand why the disease develops only in a minority of exposed individuals and why cases of chronic HP may progress without further antigen exposure.
authors.affiliation: Department of Pneumology/Allergy, Ruhrlandklinik, University Hospital, Essen, Germany. ulrich.costabel@ruhrlandklinik.uk-essen.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Costabel
authors.forename: Francesco
authors.initials: F
authors.lastname: Bonella
authors.forename: Josune
authors.initials: J
authors.lastname: Guzman
mesh_terms: D000208:Acute Disease; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D001706:Biopsy; D001716:Bird Fancier's Lung / Q000175:diagnosis; D001985:Bronchial Provocation Tests; D018893:Bronchoalveolar Lavage; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005203:Farmer's Lung / Q000175:diagnosis; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology*; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000175:diagnosis; D014057:Tomography, X-Ray Computed