The guideline group was selected to be representative of UKbased medical experts with an interest in myeloproliferative neoplasms and eosinophilia. PubMed and EMBASE were searched systematically for publications in English until August 2015 using the key words eosinophilia, hypereosinophilia, eosinophilic leukaemia and HES. The writing group produced the draft guideline, which was subsequently revised by consensus by members of the General Haematology and Haematooncology Task Forces of the British Committee for Standards in Haematology (BCSH). The guideline was then reviewed by a sounding board of UK haematologists and representatives from the Nordic MPN Study Group, the BCSH and the British Society for Haematology (BSH) Committee, and comments were incorporated where appropriate. The 'GRADE' system was used to quote levels and grades of evidence, details of which can be found in Table I. The objective of this guideline is to provide healthcare professionals with clear guidance on the investigation and management of eosinophilia.
Guideline updateThere is no previous BCSH guideline for this topic.
AimThe purpose of this guideline is to provide a practical approach to the investigation and management of eosinophilia.
Key recommendations• The underlying cause of eosinophilia should be sought and possible eosinophil-associated end-organ damage should be evaluated (Grade 1B).
Assessment of underlying cause• A detailed medical history should be taken and a thorough physical examination should be performed (Grade 1C). The history should include:o assessment for allergic disorders, skin rashes and cardiorespiratory, gastrointestinal and constitutional symptoms.o a detailed travel history, particularly for tropical travel; travel even in the remote past may be relevant.o a detailed drug history.• All patients should have a full blood count, blood film examination and routine tests of renal and liver function, a bone profile, lactate dehydrogenase, erythrocyte sedimentation rate and/or C-reactive protein and vitamin B12 assay (Grade 1C) • Patients who are otherwise well with mild to moderate eosinophilia between 0Á5 and 1Á5 3 10 9