Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Acute interstitial pneumonia (Hamman-Rich syndrome)

Talmadge E King, Jr, MD
Section Editor
Kevin R Flaherty, MD, MS
Deputy Editor
Helen Hollingsworth, MD


Acute interstitial pneumonia (AIP) is a rare and fulminant form of diffuse lung injury originally described by Hamman and Rich in 1935 [1,2]. AIP is classified as an idiopathic interstitial pneumonia (IIP), and among the IIPs, it has the most acute onset and rapidly progressive course [1-3].

AIP is similar in presentation to the acute respiratory distress syndrome (ARDS) and probably represents a subset of cases of idiopathic ARDS [4]. (See "Acute respiratory distress syndrome: Clinical features and diagnosis in adults".)

The clinical presentation, diagnosis, treatment, and prognosis of AIP will be reviewed here. The other idiopathic interstitial pneumonias and the approach to patients with interstitial lung disease are discussed separately. (See "Idiopathic interstitial pneumonias: Clinical manifestations and pathology" and "Approach to the adult with interstitial lung disease: Clinical evaluation" and "Approach to the adult with interstitial lung disease: Diagnostic testing".)


AIP generally affects previously healthy individuals without a prior history of lung disease and occurs with roughly equal frequency in men and women [5-8]. It is not associated with cigarette smoking. Most patients are over the age of 40 years, with a mean age of 50 to 55 years [3,5,6,8,9].


AIP has the histopathologic appearance of diffuse alveolar damage (DAD) [3]. DAD is a reaction pattern that occurs in response to a number of known causes of lung injury, but in the case of AIP, it is idiopathic (table 1) [10]. DAD has characteristic temporal phases in its evolution — acute exudative, organizing proliferative, and healed (or fibrotic) phases (table 2) [3,6]. (See "Idiopathic interstitial pneumonias: Clinical manifestations and pathology".)

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Nov 2017. | This topic last updated: Jan 26, 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Hamman L, Rich AR. Fulminating Diffuse Interstitial Fibrosis of the Lungs. Trans Am Clin Climatol Assoc 1935; 51:154.
  2. Hamman, L, Rich, AR. Acute diffuse interstitial fibrosis of the lungs. Bull Johns Hopkins Hosp 1944; 74:177.
  3. Olson J, Colby TV, Elliott CG. Hamman-Rich syndrome revisited. Mayo Clin Proc 1990; 65:1538.
  4. Fulmer JD, Katzenstein ALA. The interstitial lung diseases. In: Pulmonary and Critical Care Medicine, Bone RC (Ed), Mosby Year Book, St. Louis 1993. p.M1.
  5. Vourlekis JS. Acute interstitial pneumonia. Clin Chest Med 2004; 25:739.
  6. Katzenstein AL, Myers JL, Mazur MT. Acute interstitial pneumonia. A clinicopathologic, ultrastructural, and cell kinetic study. Am J Surg Pathol 1986; 10:256.
  7. Bouros D, Nicholson AC, Polychronopoulos V, du Bois RM. Acute interstitial pneumonia. Eur Respir J 2000; 15:412.
  8. Vourlekis JS, Brown KK, Cool CD, et al. Acute interstitial pneumonitis. Case series and review of the literature. Medicine (Baltimore) 2000; 79:369.
  9. Primack SL, Hartman TE, Ikezoe J, et al. Acute interstitial pneumonia: radiographic and CT findings in nine patients. Radiology 1993; 188:817.
  10. American Thoracic Society, European Respiratory Society. American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001. Am J Respir Crit Care Med 2002; 165:277.
  11. Kang D, Nakayama T, Togashi M, et al. Two forms of diffuse alveolar damage in the lungs of patients with acute respiratory distress syndrome. Hum Pathol 2009; 40:1618.
  12. Pache JC, Christakos PG, Gannon DE, et al. Myofibroblasts in diffuse alveolar damage of the lung. Mod Pathol 1998; 11:1064.
  13. Suh GY, Kang EH, Chung MP, et al. Early intervention can improve clinical outcome of acute interstitial pneumonia. Chest 2006; 129:753.
  14. Parambil JG, Myers JL, Aubry MC, Ryu JH. Causes and prognosis of diffuse alveolar damage diagnosed on surgical lung biopsy. Chest 2007; 132:50.
  15. Suda T, Kaida Y, Nakamura Y, et al. Acute exacerbation of interstitial pneumonia associated with collagen vascular diseases. Respir Med 2009; 103:846.
  16. Johkoh T, Müller NL, Taniguchi H, et al. Acute interstitial pneumonia: thin-section CT findings in 36 patients. Radiology 1999; 211:859.
  17. Mihara N, Johkoh T, Ichikado K, et al. Can acute interstitial pneumonia be differentiated from bronchiolitis obliterans organizing pneumonia by high-resolution CT? Radiat Med 2000; 18:299.
  18. Tomiyama N, Müller NL, Johkoh T, et al. Acute respiratory distress syndrome and acute interstitial pneumonia: comparison of thin-section CT findings. J Comput Assist Tomogr 2001; 25:28.
  19. Ichikado K, Suga M, Müller NL, et al. Acute interstitial pneumonia: comparison of high-resolution computed tomography findings between survivors and nonsurvivors. Am J Respir Crit Care Med 2002; 165:1551.
  20. Bonaccorsi A, Cancellieri A, Chilosi M, et al. Acute interstitial pneumonia: report of a series. Eur Respir J 2003; 21:187.
  21. Lim SY, Suh GY, Choi JC, et al. Usefulness of open lung biopsy in mechanically ventilated patients with undiagnosed diffuse pulmonary infiltrates: influence of comorbidities and organ dysfunction. Crit Care 2007; 11:R93.
  22. Parambil JG, Myers JL, Ryu JH. Diffuse alveolar damage: uncommon manifestation of pulmonary involvement in patients with connective tissue diseases. Chest 2006; 130:553.
  23. Park IN, Kim DS, Shim TS, et al. Acute exacerbation of interstitial pneumonia other than idiopathic pulmonary fibrosis. Chest 2007; 132:214.
  24. Avnon LS, Pikovsky O, Sion-Vardy N, Almog Y. Acute interstitial pneumonia-Hamman-Rich syndrome: clinical characteristics and diagnostic and therapeutic considerations. Anesth Analg 2009; 108:232.
  25. Quefatieh A, Stone CH, DiGiovine B, et al. Low hospital mortality in patients with acute interstitial pneumonia. Chest 2003; 124:554.
  26. Robinson DS, Geddes DM, Hansell DM, et al. Partial resolution of acute interstitial pneumonia in native lung after single lung transplantation. Thorax 1996; 51:1158.
  27. Ogawa D, Hashimoto H, Wada J, et al. Successful use of cyclosporin A for the treatment of acute interstitial pneumonitis associated with rheumatoid arthritis. Rheumatology (Oxford) 2000; 39:1422.