From the Guidelines
If you have a high eosinophil count, you should consult with your healthcare provider for proper diagnosis and treatment, as persistent eosinophilia can cause significant end-organ damage, particularly affecting the heart, lungs, and central nervous system 1. Eosinophilia is a condition where the eosinophil count in the peripheral blood is elevated, and it can be caused by various factors, including helminth infections, allergic reactions, certain medications, autoimmune disorders, and some cancers.
- Common causes of eosinophilia include:
- Helminth infections, such as Strongyloides stercoralis and Schistosoma haematobium, which can cause long-term health problems and even mortality in immunocompromised individuals 1
- Allergic reactions, which can be treated with antihistamines like cetirizine (10mg daily) or corticosteroids
- Certain medications, which can trigger eosinophilia as a side effect
- Autoimmune disorders, which can cause eosinophilia as part of the disease process
- Some cancers, which can produce eosinophil-stimulating factors Your doctor will likely recommend additional tests, such as:
- Stool examinations for parasites
- Allergy testing
- Blood smear examination
- Further work-up of non-EoE eosinophilic gastrointestinal (GI) disease, hypereosinophilic syndrome, and eosinophilic granulomatosis with polyangiitis (EGPA) in patients with esophageal symptoms and hypereosinophilia (absolute eosinophil count [AEC] >1500 cells/uL) 1 Treatment depends entirely on the underlying cause, and in some cases, simply removing the triggering medication or allergen resolves the condition.
- For parasitic infections, antiparasitic medications like albendazole (400mg twice daily for 3-5 days) might be needed
- For allergies, antihistamines like cetirizine (10mg daily) or corticosteroids may be prescribed
- For hypereosinophilic syndrome, treatment may involve corticosteroids, immunomodulatory therapies, or targeted therapies 1 It is essential to note that eosinophils are white blood cells that help fight certain infections and participate in allergic responses, so their elevation indicates your immune system is responding to something. Without treatment of the underlying cause, persistent high eosinophil counts can potentially damage tissues and organs over time, particularly the heart, lungs, and nervous system 1.
From the Research
Definition and Classification of Eosinophilia
- Eosinophilia is defined as a peripheral blood eosinophil count greater than 500 eosinophils/μL, whereas hypereosinophilia is defined as an absolute eosinophil count (AEC) of ≥1500 eosinophils/μL 2.
- The 2016 World Health Organization endorses a semi-molecular classification scheme of disease subtypes, including "myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB, or FGFR1 or with PCM1-JAK2" 3.
Causes and Evaluation of Eosinophilia
- Eosinophilia can be secondary to allergies, infections, medication reactions, autoimmune diseases, or other conditions 2.
- A meticulous approach to exploring key aspects of the medical history is recommended for assessing increased AECs, including the onset of eosinophilia and any coincident events, such as travel or the start of new medications 2.
- Evaluation of persistent eosinophilia involves correlation of clinical history, laboratory data, cellular morphology, and ancillary testing 4.
Diagnosis and Treatment of Eosinophilia
- Primary eosinophilia is considered either "clonal" or "idiopathic" based on the presence or absence of either a molecular or bone marrow histological evidence for a myeloid neoplasm 5.
- Hypereosinophilic syndrome (HES) is a subcategory of idiopathic eosinophilia and is characterized by an absolute eosinophil count of > or =1.5 x 10(9)/l for at least 6 months as well as eosinophil-mediated tissue damage 5.
- Treatment options for eosinophilia include imatinib, corticosteroids, hydroxyurea, and interferon-alpha, as well as monoclonal antibodies to either interleukin-5 (mepolizumab) or CD52 (alemtuzumab) 3, 5.
Approach to Patients with Eosinophilia
- Physicians may encounter blood or tissue eosinophilia through a routine complete blood count with differential or a tissue pathology report 6.
- A general approach to evaluating eosinophilia includes determining the absolute eosinophil count, exploring the medical history, and performing ancillary testing as needed 2, 4.
- Future challenges include determining which eosinophil-associated diseases benefit from eosinophil-targeted therapy and identifying biomarkers for disease activity and diagnosis 6.