Audience

  • Highland HSCP 

The normal eosinophil count is 0.04 to 0.4 × 109/L. Eosinophils play a part in allergic, parasitic and malignant disease processes as well as tissue repair and remodelling. Hypereosinophilia is defined as an elevation of the eosinophil count 1·5 × 109/L or greater persisting for at least six months for which no underlying cause can be found. It can be associated with signs of organ dysfunction (cardiac, respiratory, gastrointestinal and neurological).

Eosinophilia related to underlying causes e.g. respiratory disease, autoimmune disease is not reviewed by haematology. A haematological disorder causing eosinophilia is the lowest probability diagnosis.

Causes

  • Atopy and/or allergy eg. asthma, eczema
  • Infections – parasites, fungal, HIV
  • Medications – ACE inhibitors, penicillin, anti-epileptics, PPI – check BNF 
    • DRESS syndrome (occurs three to six weeks after the introduction of a new drug and is characterised by a triad of a skin eruption, fever and internal organ involvement)
  • Autoimmune
    • Eosinophilic granulomatosis with polyangitis
    • Polyarteritis nodosa
    • SLE
    • Idiopathic eosinophilic synovitis
    • Eosinophilic fasciitis (Shulman disease)
    • Rheumatoid arthritis
  • Dermatological
    • Wells syndrome (eosinophilic cellulitis)
    • Pemphigoid
  • Gastrointestinal
    • Chronic pancreatitis
    • Inflammatory bowel disease
    • Coeliac
  • Respiratory
    • Allergic broncho-pulmonary aspergillosis
    • Asthma
    • Sarcoidosis
    • Löffler syndrome
    • Eosinophilic pneumonia
  • Malignant disorders
    • Solid organ tumour with aberrant production of cytokines
    • Hodgkin lymphoma
    • T-cell non-Hodgkin lymphoma
    • Mastocytosis
    • Clonal or malignant eosinophilic disorders e.g. CML
  • Hyposplenism
  • Adrenal insufficiency

History and examination 

There is such a wide variety of differentials that a systematic approach is required. Travel history is important. Look at older blood counts.

Suggested investigations

  • Blood film
  • Inflammatory markers
  • Renal and liver function
  • Calcium
  • Stool ova cysts and parasites and other markers of infection as guided by history e.g. strongyloides serology
  • Coeliac screen
  • Autoimmune screen and ANCA
  • IgE
  • Serum tryptase
  • Chest radiograph if respiratory features

Management

Please refer urgently if:

  • Eosinophil count over 10 × 109/L without an obvious underlying cause
  • Eosinophil count persistently over 5 × 109/L with end organ damage or features of haematological malignancy

Eosinophilia related to clear underlying causes e.g. respiratory disease, autoimmune disease is not reviewed by haematology

 

Editorial Information

Last reviewed: 29/01/2024

Next review date: 31/01/2027

Author(s): Haematology Department .

Version: 2

Approved By: APPROVED TAM Subgroup of the ADTC

Reviewer name(s): Dr P Forsyth, Consultant Haematologists .

Document Id: TAM614