A Case of Pulmonary Hypertension Associated with Idiopathic Hypereosinophilic Syndrome.

Hypereosinophilic syndrome (HES) is characterized by multi-organ damage that is associated with tissue hypereosinophilia. A persistently elevated eosinophilic count is also required for the diagnosis of HES. Although HES affects various organs, damage to pulmonary artery is rarely reported. We present a case of a 39-year-old man who was diagnosed with pulmonary hypertension (PH) associated with idiopathic HES. Although the pulmonary arterial hypertension specific drugs including intravenous epoprostenol could not control his PH, corticosteroid was effective for both hypereosinophilia and PH. Our case suggests the importance of steroid therapy as well as specific drugs for pulmonary arterial hypertension in the treatment of PH associated with HES.