The common causes of eosinophilia are allergy (asthma, eczema, seasonal allergies) and medication (sometimes self-administered).
A more extensive list of causes is found here:
Consider intestinal / other parasites if travel history, even long ago, suggests this as a possibility.
Sustainedly raised eosinophils are toxic especially at levels above 1.5x 109/l.
If there are associated new onset cardiac or pulmonary problems seek early advice.
Medication including accurate start dates, and time correlation with blood counts
Red flag malignancy symptoms ( night sweats, unintentional weightloss, pruritus)
Signs of allergy
Cardiac and respiratory systems
FBC and blood film
U+E, LFT, bone, LDH, CRP, vitamin B12 assay
According to above findings consider:
Stool sample requesting Ova, Cysts and Parasites
CXR, Pulmonary Function Test and possible CT thorax
Troponin T and possible Echocardiography
When to refer:
Eosinophil count is sustained above 1.5x 109/l
Evidence of end organ damage
Refer to Haematology if no detectable secondary cause
Refer to secondary care, specialty according to clinical impression and site of pathology
BJH, Guideline for the investigation and management of eosinophilia: http://onlinelibrary.wiley.com/doi/10.1111/bjh.14488/full
Dr Richard Noble, Consultant Haematologist, RCHT
Dr Bridgitte Wesson, GP & Kernow RMS Haematology guideline lead
Review date: 13/07/2020
Next Review 13/07/2021