Hypereosinophilic Syndrome

Hypereosinophilic syndrome (HES) refers to a rare group of conditions that are associated with persistent eosinophilia with evidence of organ involvement. Signs and symptoms vary significantly based on which parts of the body are affected. Although any organ system can be involved in HES, the heart, central nervous system, skin, and respiratory tract are the most commonly affected. The condition was originally thought to be "idiopathic" or of unknown cause. However, recent advances in diagnostic testing have allowed a cause to be identified in approximately a quarter of cases. Management varies based on the severity of the condition and whether or not an underlying cause has been identified but generally includes imatinib or corticosteroids as an initial treatment.