High Quality Content by WIKIPEDIA articles! Eosinophilic pneumonia (EP) is a disease in which a certain type of white blood cell called an eosinophil accumulates in the lung. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. EP is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and x-rays. Prognosis is excellent once most EP is recognized and treatment with corticosteroids is begun.