Other interstitial pneumonitis / fibrosis

Idiopathic eosinophilic pneumonia

Topic Completed: 1 September 2011

Minor changes: 10 May 2021

Copyright: 2003-2021,, Inc.

PubMed search: idiopathic eosinophilic pneumonia

Elliot Weisenberg, M.D.
Page views in 2020: 1,326
Page views in 2021 to date: 1,290
Cite this page: Weisenberg E. Idiopathic eosinophilic pneumonia. website. Accessed October 24th, 2021.
Definition / general
  • Diagnosis of exclusion
  • Lung disease associated with eosinophils in alveolar and interstitial spaces, usually with peripheral eosinophilia, but excluding Langerhans cell histiocytosis
  • Must exclude drug reactions (antibiotics, cytotoxic or anti-inflammatory drugs), immune disorders (Churg-Strauss syndrome, collagen vascular disease, asthma, hypereosinophilic syndrome, chronic eosinophilic leukemia NOS, myeloid and lymphoid neoplasms with eosinophilia and rheumatoid arthritis), infections (bacteria, Aspergillus, HIV, parasites - helminths, Dirofiliaria and filarial) or tobacco (flavored cigars, Chest 2007;131:1234, new onset of smoking, JAMA 2004;292:2997)
Clinical features
  • Symptoms: fever, weight loss and shortness of breath
  • Xray: peripheral infiltrate
  • Classified as simple, acute or chronic
  • Simple eosinophilic pneumonia: see Loeffler syndrome
  • Acute eosinophilic pneumonia: onset in 1 - 4 days, accompanied by fever, cough, dyspnea and chest pain; unknown cause, prominent eosinophils in bronchoalveolar lavage fluid (Am J Respir Crit Care Med 2002;166:1235) and diffuse alveolar damage at biopsy
  • Chronic eosinophilic pneumonia
Case reports
  • 6 year old boy post chemotherapy for neuroblastoma with bilateral pulmonary infiltrates (Case #105)
  • Steroids cause dramatic response to acute or chronic forms
Microscopic (histologic) description
  • Acute form has diffuse alveolar damage
  • Alveolar and interstitial infiltration by eosinophils, also plasma cells and histiocytes
  • May have Charcot-Leyden crystals
  • Variable angiitis, granulomatosis, fibrosis, mucus plugging and bronchiolitis with necrosis
Microscopic (histologic) images

Case #105

Acute eosinophilic pneumonia

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