Eosinophils play two roles in your immune system:

  • Destroy foreign substances. Eosinophils consume matter flagged by your immune system as harmful. For example, they fight matter from parasites.
  • Control infection. Eosinophils swarm an inflamed site when needed. This is important to fight disease. But too much can cause more discomfort or even tissue damage. For example, these cells play a key role in the symptoms of asthma and allergies, such as hay fever. Other immune system issues can lead to chronic inflammation as well.

Eosinophilia happens when eosinophils swarm a site in the body. Or when the bone marrow makes too many. This can happen due to many reasons including:

  1. Parasitic and fungal diseases
  2. Allergic reactions
  3. Adrenal conditions
  4. Skin disorders
  5. Toxins
  6. Autoimmune disorders
  7. Endocrine conditions.
  8. Tumors

Certain diseases and conditions that can cause blood or tissue eosinophilia include:

  1. Acute myelogenous leukemia (AML)
  2. Allergies
  3. Ascariasis (a roundworm infection)
  4. Asthma — a long-term condition that affects airways in the lungs.
  5. Atopic dermatitis (eczema)
  6. Cancer
  7. Churg-Strauss syndrome
  8. Crohn's disease
  9. Drug allergy
  10. Eosinophilic esophagitis
  11. Eosinophilic leukemia
  12. Hay fever (allergic rhinitis)
  13. Hodgkin's lymphoma (Hodgkin's disease)
  14. Hypereosinophilic syndrome
  15. Idiopathic hypereosinophilic syndrome (HES), an extremely high eosinophil count of unknown origin
  16. Lymphatic filariasis (a parasitic infection)
  17. Ovarian cancer
  18. Parasitic infection
  19. Primary immunodeficiency
  20. Trichinosis (a roundworm infection)
  21. Ulcerative colitis (a type of inflammatory bowel disease)

Parasites and allergies to medicines are common causes of eosinophilia. Hypereosinophilia can cause organ damage. This is called hypereosinophilic syndrome. The cause for this syndrome is often unknown. But it can result from some types of cancer such as bone marrow or lymph node cancer.

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

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Sept. 08, 2023