Acute eosinophilic pneumonia (AEP) is a rare disorder characterized by the rapid accumulation of eosinophils in the lungs (pulmonary eosinophilia). Eosinophils are a type of white blood cell and are part of the immune system. They are usually produced in response to allergens, inflammation or infection (especially parasitic ones) and are particularly active in the respiratory tract. Common symptoms associated with AEP include progressive shortness of breath (dyspnea) of rapid onset and possibly acute respiratory failure, cough, fatigue, night sweats, fever, and unintended weight loss. The exact cause of the disorder is unknown (idiopathic) in many cases, however recent change in tobacco smoking habits and drug intake can trigger the disease. Outcome is favorable with corticosteroids, without relapse.Introduction
AEP was first described as a distinct entity in the medical literature in 1989. AEP is classified as a form of eosinophilic lung disease, a large group of interstitial lung diseases. AEP is different from chronic eosinophilic pneumonia (CEP), which is marked by slower progression, lack of progression to acute respiratory failure, frequent relapses and is often associated with asthma. For more information on CEP, choose "chronic eosinophilic pneumonia" as your search term in the NORD Rare Disease Database.