Canterbury DHB



This section provides a basic review of the work-up and management of eosinophilia. For a more comprehensive review, see the 2017 BCSH guidelines (Butt NM, et al.).1

Eosinophils arise from CD34 positive cells, which are often pre-committed progenitors bipotent for eosinophils and basophils. They produce and store pro-inflammatory proteins and cytokines which, when chronically in excess, may cause tissue and/or organ damage. Work-up should therefore include assessing organ damage, as guided by symptoms. Hypereosinophilia is generally defined as a peripheral blood eosinophil count >1.5 x 109/L.

There are numerous reactive/secondary causes of eosinophilia, many of which are included in the table below. A thorough history, careful examination, and often targeted investigation are required to exclude a secondary cause. However, the 2017 BCSH guidelines1 recommend that all patients have as a minimum initial blood panel:

Manage a reactive eosinophilia by treating the underlying condition. If the underlying condition is not amenable to treatment, the eosinophilia itself can often be managed with corticosteroids or hydroxyurea.

See the 2017 BCSH guidelines,1 table 2 page 5 for causes of eosinophilia.

In This Section

Causes of Eosinophilia

Chronic Eosinophilic Leukaemia – Not Otherwise Specified (CEL-NOS)

Diagnostic Criteria for CEL

Prognosis and Management of CEL-NOS

Idiopathic Hypereosinophilic Syndrome (HES)

Myeloid and Lymphoid Neoplasms with Eosinophilia and Abnormalities of PDGFRA, PDGFRB, FGFR1, or with PCM1-JAK2


Further Reading

About this Canterbury DHB document (6246):

Document Owner:

Bridgett McDiarmid (see Who's Who)

Last Reviewed:

August 2018

Next Review:

April 2021


Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document. Disclaimer

Topic Code: 6246