Canterbury DHB


Idiopathic Hypereosinophilic Syndrome (HES)

If no evidence of clonality is found, and there is no increase in myeloblasts, diagnose idiopathic hypereosinophilic syndrome (HES). HES is defined as >1.5 x 109/L peripheral blood eosinophils for >6 months, associated with signs of organ involvement and dysfunction, after excluding all causes of reactive eosinophilia and haematological disorders. Where the above criteria are met but there is no organ damage, the term idiopathic eosinophilia is most appropriate.

Patients with HES may present with a variety of clinical symptoms and/or syndromes such as those in the table below.

If patients require treatment, first-line therapy is usually with corticosteroids: methylprednisolone 1mg/kg/day if very severe life-threatening condition. Consider concomitant allopurinol if very high eosinophil counts, and ivermectin cover if any suggestion of strongyloides infection. Or, for more modest symptoms, oral prednisone at 0.5-1mg/kg/day for one to two weeks, tapering off over two to three months.

Maintenance doses may be required.

Approaches to consider for steroid refractory disease include:

See Valent P (2009),4 table 2 page 5.

About this Canterbury DHB document (6224):

Document Owner:

Bridgett McDiarmid (see Who's Who)

Last Reviewed:

August 2018

Next Review:

April 2021


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Topic Code: 6224