Background: The idiopathic hypereosinophilic syndrome (HES) is a rare disease characterized by persistent
idiopathic eosinophilia associated with a diffuse infiltration of various organs by eosinophils.
We reported a case of idiopathic HES.
Case Report: This patient was a 33-year old woman who presented with skin eruption, pulmoner involvement
and pericardial effusion. The laboratory studies were consistent with HES.
Conclusions: The clinical picture and blood eosinophilia markedly improved with systemic corticosteroid therapy. Physicians should consider HES in the differential diagnosis of patients presenting with cutaneous and respiratory manifestations, pericarditis and eosinophilia.

Keywords: Hypereosinophilic Syndrome, Pericarditis, pulmonary involvement