Idiopathic Acute Eosinophilic Pneumonia

A histopathologic pattern of eosinophilic infiltration of the interstitium and alveolar spaces has been termed eosinophilic pneumonia (EP). Diseases with this underlying pattern have been further categorized based on primary (or idiopathic) or secondary (or known) etiologies. Secondary etiologies including drug toxicity and parasitic and fungal infections need to be excluded before a diagnosis of a primary EP can be made. Primary lung-limited EP conditions include idiopathic acute eosinophilic pneumonia (IAEP) and idiopathic chronic eosinophilic pneumonia (ICEP) (Cordier 2003). IAEP and ICEP differ with respect to clinical presentation, proposed diagnostic criteria, recommended therapies, and outcome.