Eosinophilia (e-o-sin-o-FIL-e-uh) is a higher than normal level of eosinophils. Eosinophils are a type of disease-fighting white blood cell.
You can have high levels of eosinophils in your blood (blood eosinophilia). High levels of eosinophils may also occur in your body’s tissues at the site of an infection or inflammation (tissue eosinophilia).
Tissue eosinophilia may be found in samples taken during an exploratory procedure or in samples of certain fluids, such as mucus released from nasal tissues. If you have tissue eosinophilia, the level of eosinophils in your bloodstream is likely normal.
Blood eosinophilia may be detected with a blood test, usually as part of a complete blood count. A count of more than 500 eosinophils per microliter of blood is generally considered eosinophilia in adults. A count of more than 1,500 eosinophils per microliter of blood that lasts for several months is called hypereosinophilic syndrome.
Causes of Eosinophilia
When parasites enter the normal flow of blood during the second stage of cardiosphillia (small spots between the ventricles) this stage is called the serious one. Eosinophilia can be idiopathic (primary) or, more commonly, secondary to another disease. In the Western World, allergic or atopic diseases are the most common causes, especially those of the respiratory or integumentary systems. In the developing world, parasites are the most common cause. A parasitic infection of nearly any bodily tissue can cause eosinophilia. Diseases that feature eosinophilia as a sign include the following:
- Allergic disorders
- Hay fever
- Drug allergies
- Allergic skin diseases
- Dermatitis herpetiformis
- Eosinophilic esophagitis
- Eosinophilic gastroenteritis
- Parasitic infections
- Some forms of malignancy
- Acute lymphoblastic leukemia
- Chronic myelogenous leukemia
- Eosinophilic leukemia
- Hodgkin lymphoma
- Some forms of non-Hodgkin lymphoma
- Systemic autoimmune diseases (e.g., SLE, idiopathic eosinophilic synovitis)
- Systemic mastocytosis
- Some forms of vasculitis (e.g., Churg-Strauss syndrome)
- Cholesterol embolism (transiently)
- Coccidioidomycosis (Valley fever), a fungal disease prominent in the US Southwest.
- Human immunodeficiency virus infection
- Interstitial nephropathy
- Hyperimmunoglobulin E syndrome, an immune disorder characterized by high levels of serum IgE
- Idiopathic hypereosinophilic syndrome.
When does Eosinophilia occur?
Eosinophilia occurs in a wide range of conditions. Its commonest causes in the UK are allergic diseases such as asthma and hay fever, whereas worldwide the main cause is parasitic infection. It can also occur in relation to common skin diseases, medicine reactions, and parasitic infections. Other rarer causes include:
- lung diseases, eg Loeffler’s syndrome
- vasculitis (inflammation of blood vessels), eg Churg-Strauss syndrome
- some tumours, eg lymphoma
- liver cirrhosis
- some antibody deficiencies; not typically AIDS
- other rarer skin diseases, eg dermatitis herpetiformis
- uknown causes, labelled hypereosinophilic syndrome.
Treatment of Eosinophilia
Treatment tackles the underlying cause of the condition, whether it is an allergy, a medicine reaction, or a parasitic infection. These treatments are usually effective, and fairly non-toxic.
Treatment for hypereosinophilic syndrome is oral corticosteroid therapy, usually starting with prednisolone (eg Deltacortril) at single daily doses of 30-60mg. If this is not effective, a chemotherapeutic agent is administered.