1. Hypersensitivity pneumonitis: A fibrosing alveolitis produced by inhalation of diverse antigens 
Paul A. Greenberger, MD 
Journal of Allergy and Clinical Immunology 
Volume 143, Issue 4, Pages (April 2019)
DOI: /j.jaci
Copyright © 2018 American Academy of Allergy, Asthma & Immunology Terms and Conditions

2. Fig 1
The diagnosis of HP depicted in clinical, histologic, and BAL findings. NSIP, Nonspecific interstitial pneumonitis.
Journal of Allergy and Clinical Immunology  , DOI: ( /j.jaci )
Copyright © 2018 American Academy of Allergy, Asthma & Immunology Terms and Conditions

3. Fig 2
Lung parenchyma with aggregate of histiocytes consistent with a loose granuloma of HP (×200 magnification). Courtesy of Anjanda V. Yeldandi, MD, Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Journal of Allergy and Clinical Immunology  , DOI: ( /j.jaci )
Copyright © 2018 American Academy of Allergy, Asthma & Immunology Terms and Conditions

4. Fig 3
Lung parenchyma with thickening (expansion) of the alveolar septae by the interstitial lymphocytic infiltrates of HP (×100 magnification). Courtesy of Anjanda V. Yeldandi, MD, Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Journal of Allergy and Clinical Immunology  , DOI: ( /j.jaci )
Copyright © 2018 American Academy of Allergy, Asthma & Immunology Terms and Conditions