This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Elevated eosinophils

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Eosinophilia is a raised eosinophil count (1,2,3,4)

This occurs where the eosinophil count is greater than 0.44 x 10^9/l (3)

  • however has been noted that the normal range for a peripheral blood eosinophil count in healthy individuals is generally defined internationally as 0.05-0.5×10^9/L (4)
    • eosinophilia is a raised number of eosinophils in peripheral blood (>0.5×10^9/L)
    • hypereosinophilia is >=1.5×109/L on two tests separated by at least one month
    • eosinophil count can vary with extremes of age
      • eosinophil levels are higher in neonates than adults and gradually reduce in older people.

It may be a feature of the following conditions:

  • asthma and allergic disorders - asthma, hypersensitivity, drugs, angioneurotic oedema
  • parasitic infections - especially schistosomiasis, echinococciasis
  • polyarteritis nodosa
  • Churg-Strauss syndrome
  • Addison's disease
  • skin disease - pemphigus, urticaria, eczema, dermatitis herpetiformis, erythema multiforme
  • malignancy:
    • Hodgkin's disease
    • carcinoma
    • haematological malignancies:
      • chronic myeloid leukaemia
      • other myeloproliferative syndromes
      • eosinophilic leukaemia
  • Loeffler's syndrome
  • Loeffler's endocarditis
  • scarlet fever
  • irradiation
  • during convalescence from any infection
  • hypereosinophilic syndrome
  • post-splenectomy
  • cholesterol emboli syndrome
  • drugs that may cause raised eosinophil count include (1,2,3,4):
    • antimicrobials
      • such as penicillins, cephalosporins, nitrofurantoin, tetracyclines, daptomycin, fluoroquinolones
    • sulphonamides
      • such as sulfasalazine, septrin, dapsone
    • ranitidine
    • allopurinol
    • angiotensin converting enzyme (ACE) inhibitors
    • anticonvulsants
      • such as phenytoin, carbamazepine, lamotrigine
    • antiretrovirals
      • nevirapine, abacavir
    • non-steroidal anti-inflammatory drugs (NSAIDs)
    • methotrexate
    • interleukin-2 (IL-2)

If raised eosinophil count in an adult (3):


Factors such as intercurrent steroid treatment and bacterial or viral infection can transiently lower eosinophil counts (4)


  • Felig P et al (2001) Endocrinology and Metabolism. McGraw-Hill.
  • Hart FD (Ed) (2005). French's Index of Differential Diagnosis.
  • NHS Camden CCG. Abnormal FBC guidance - for adults (Accessed 30/10/19)
  • Thakker C, Booth H L, Lambert J, Morgan S, Checkley A M. Investigating eosinophilia BMJ 2023; 380 :e070295 doi:10.1136/bmj-2022-070295

Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.


Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.