Chronic hypersensitivity pneumonitis

Clin Chest Med. 2012 Mar;33(1):151-63. doi: 10.1016/j.ccm.2011.12.004. Epub 2012 Jan 24.


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.

Publication types

  • Review

MeSH terms

  • Acute Disease
  • Alveolitis, Extrinsic Allergic / diagnosis*
  • Alveolitis, Extrinsic Allergic / diagnostic imaging
  • Alveolitis, Extrinsic Allergic / epidemiology
  • Alveolitis, Extrinsic Allergic / pathology
  • Alveolitis, Extrinsic Allergic / physiopathology
  • Alveolitis, Extrinsic Allergic / therapy
  • Biopsy
  • Bird Fancier's Lung / diagnosis
  • Bronchial Provocation Tests
  • Bronchoalveolar Lavage
  • Chronic Disease
  • Diagnosis, Differential
  • Farmer's Lung / diagnosis
  • Humans
  • Lung / diagnostic imaging*
  • Lung / pathology*
  • Prognosis
  • Pulmonary Fibrosis / diagnosis
  • Tomography, X-Ray Computed