title: Hypersensitivity pneumonitis.
abstract: OBJECTIVE
  To bring readers up to date on recent reports, both clinical and basic understanding, on hypersensitivity pneumonitis.
  
  
  RESULTS
  Although many antigens and environmental settings have already been described as sources of this hyperimmune pulmonary disease, the literature continues to bring forth other conditions that can cause hypersensitivity pneumonitis. We also highlight new findings in the diagnosis of hypersensitivity pneumonitis, its histopathology, insight into its potential outcomes, and understanding of its immune mechanisms that could lead to new treatments.
  
  
  CONCLUSIONS
  The review will help clinicians in their diagnostic approach to hypersensitivity pneumonitis and lead them to look for other potential sources of the disease. The findings described will help guide further research on the pathophysiology and seek new treatments for this worldwide orphan disease.
authors.affiliation: Centre de recherche de l'Institut universitaire de Cardiologie et de Pneumologie de Québec, Quebec City, Quebec, Canada.
authors.forename: Mélissa
authors.initials: M
authors.lastname: Girard
authors.forename: Yvon
authors.initials: Y
authors.lastname: Cormier
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology*; D001985:Bronchial Provocation Tests; D003937:Diagnosis, Differential; D004781:Environmental Exposure / Q000009:adverse effects; D005355:Fibrosis; D005658:Fungi / Q000276:immunology*; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D011379:Prognosis; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging / Q000473:pathology*; D013902:Radiography, Thoracic; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000946:Antigens, Fungal