Hypereosinophilic Syndrome

Hypereosinophilic Syndrome
The hypereosinophilic syndrome, defined as persistent eosinophilia (more than 1500 cells per cubic millimeter) of at least 6 months' duration leading to end-organ damage and without evidence of a clonal or reactive cause, is a diagnosis of exclusion. This syndrome is rare and accounts for less than 1% of eosinophilic diseases. It occurs predominantly in men and if, left untreated, usually has a progressive, fatal course. In hypereosinophilic syndrome almost any organ (including the bone marrow, heart, skin, and nervous system) can be affected either by eosinophilic infiltration or by thromboembolism.

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New England Journal of Medicine - Vol. 360, No. 19, May 7, 2009