Pulmonary Arterial Hypertension Associated With Idiopathic Hypereosinophilic Syndrome: Importance of Eosinophilia Control With Steroid Therapy

Basic and autopsy-based studies suggest that eosinophilic infiltration causes the progression of pulmonary vascular lesions. Pulmonary arterial hypertension (PAH) associated with hypereosinophilia is rare. We report the case of a 48-year-old woman diagnosed with PAH and idiopathic hypereosinophilic syndrome (IHES) 12 and 11 years earlier, whose hypereosinophilia and pulmonary hypertension (PH) worsened and improved with prednisolone (PSL) dosage reduction and increase, respectively. Effective management of PAH associated with IHES should include eosinophilia control through appropriate steroid therapy, highlighting that eosinophilia-associated inflammation might be linked to a subset of pulmonary vascular diseases.