[Eosinophilic pneumonia, how to differentiate: classification and diagnostic approach].

Eosinophilic pneumonia is characterized by pulmonary eosinophilia associated with and/or alveolar eosinophilia. Furthermore, blood eosinophilia may be absent particularly in patients who have benefited beforehand of corticosteroids. The most common causes are parasites and drugs. According to the classification, we distinguish idiopathic pneumonia with eosinophils, those related to vasculitis and those of known etiology. Extrapulmonary involvement is frequently found in the subgroup of vasculitis. It is important to diagnose and start treatment quickly to reduce the risk of complications. The primary treatment is based on corticosteroids and in severe cases of vasculitis immunosuppressants are necessary.