Acute eosinophilic pneumonia

[Raeanne Dimick]

Acute eosinophilic pneumonia (AEP) is a disorder of unknown etiology characterized by rapid eosinophilic infiltration of the lung interstitium.
(See also Overview of Eosinophilic Pulmonary Diseases.)
In contrast to chronic eosinophilic pneumonia, acute eosinophilic pneumonia is an acute illness that does not usually recur. Incidence and prevalence are unknown. Acute eosinophilic pneumonia can occur at any age but most often affects patients between 20 and 40 years, with a male-to-female ratio of 2:1.
The cause is unknown, but acute eosinophilic pneumonia may be an acute hypersensitivity reaction to an unidentified inhaled antigen in an otherwise healthy person. Cigarette or other smoke exposure may be involved.