Lung - nontumor
Other interstitial pneumonitis / fibrosis
Acute interstitial pneumonia

Author: Elliot Weisenberg, M.D. (see Authors page)

Revised: 28 February 2017, last major update September 2011

Copyright: (c) 2003-2017,, Inc.

PubMed search: acute interstitial pneumonia [title]

Cite this page: Acute interstitial pneumonia. website. Accessed August 20th, 2017.
Definition / general
  • Acute lung injury (clinically adult respiratory distress syndrome) without an identifiable cause
  • Also called Hamman-Rich syndrome, noncardiogenic pulmonary edema
  • Due to endothelial or epithelial injury, both result in decreased integrity of alveolar capillary membrane
  • Imbalance of proinflammatory and anti-inflammatory mediators is present
  • Neutrophils increase in alveoli and interstitium and release metabolites leading to lung injury
Clinical features
  • Rapidly progressive disease, death usually within 2 months
  • Typically, adults (mean age 50) with influenza-like illness followed by shortness of breath, no sex predilection
  • Survivors may suffer recurrences or develop chronic lung injury
Microscopic (histologic) description
  • Resembles diffuse alveolar damage with type II pneumocyte hyperplasia, typically followed by brisk interstitial fibroblastic proliferation