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