Idiopathic chronic eosinophilic pneumonia.

Idiopathic chronic eosinophilic pneumonia is a rare disorder of unknown cause with nonspecific respiratory and systemic symptoms but rather characteristic peripheral alveolar infiltrates on imaging. The disorder is highly responsive to oral corticosteroid therapy. However, relapses are frequent when tapering or after stopping treatment. Moreover, some patients develop severe asthma at some time in the follow-up. The high incidence of relapses and prevalence of severe asthma is responsible for the great proportion of patients with idiopathic chronic eosinophilic pneumonia who require prolonged oral corticosteroid therapy. There are tight links between asthma and idiopathic chronic eosinophilic pneumonia. These links might help in the comprehension of the pathogenesis of both diseases. Interestingly, there might exist a continuum between hypereosinophilic asthma, idiopathic chronic eosinophilic pneumonia, and the Churg-Strauss syndrome.