Chronic eosinophilic pneumonia followed by Churg-Strauss syndrome.

Chronic eosinophilic pneumonia and Churg-Strauss syndrome are two uncommon conditions of unknown etiology that share similar pulmonary manifestations. Whereas chronic eosinophilic pneumonia mainly targets the lung, Churg-Strauss syndrome is a systemic diseases. We report three patients who developed Churg-Strauss syndrome about eight years after being diagnosed with chronic eosinophilic pneumonia. Hypereosinophilia and high IgE levels were present in both conditions. Elevation of IgA levels was consistently demonstrated at the time of the diagnosis of Churg-Strauss syndrome. IgA elevation may be useful as a marker for progression of chronic eosinophilic pneumonia to Churg-Strauss syndrome.