Lab Test: Eosinophil Count
- Measurement of eosinophils in whole blood for the evaluation and management of allergic, hematologic, and infectious diseases, as well as parasitic infestations
- Relative: 0%-8%
- Absolute: 0-0.45 cells X 109/L
- Neonates, birth to 28 days:
- Absolute: 0-0.9 X 103 cells/microL
- Infants, 1 week to 6 months:
- Absolute: 0.2-0.3 X 103 cells/microL
- Infants, 1 year:
- Relative: 2.6%
- Absolute: 0.3 X 103 cells/microL
- Infants, 2 years:
- Absolute: 0-0.7 X 103 cells/microL
- Children, 4 to 10 years:
- Relative: 2.4%-2.8%
- Absolute: 0-0.6 X 103 cells/microL
- Evaluation of asthma severity - the eosinophil count is normally only 2% to 3%, but in asthmatics, the count may be elevated to 5% or more, and the absolute total eosinophil count may increase to more than 350/mm3. Elevated eosinophil count in asthma is a marker of severity and risk of death.
- HIV/AIDS - eosinophilia in HIV infection is associated with a high incidence of cutaneous disease (e.g., atopic dermatitis, eosinophilic pustular folliculitis), but not with other conditions commonly associated with eosinophilia (e.g., parasitic infections, malignancy, allergic reactions). Therefore, extensive work-up for asymptomatic eosinophilia in HIV-infected persons with cutaneous disease is probably unwarranted.
- Suspected anisakiasis - modest eosinophilia from 30% to 40% is a common finding in patients with gastric anisakiasis.
- Suspected atopic dermatitis - eosinophilia is associated with atopic dermatitis, particularly in conjunction with respiratory allergic disease. Elevated counts during infancy is predictive of allergic disease during the first six years of life.
- Suspected hypereosinophilic syndrome - in the absence of other known causes, absolute eosinophil counts at or above 1500 cells/microL sustained for at least 6 months, in conjunction with organ damage, may be classified as hypereosinophilic syndrome.
- Suspected schistosomiasis - during the acute phase, eosinophilia may be as high as 70%.
- Suspected Strongyloidesinfection - tissue-invasive parasitosis, including strongyloidiasis, is a common cause of secondary eosinophilia, with values often exceeding 400 cells/microL.
- Suspected Trichnella spiralis infection (trichinosis) - eosinophilia occurs in more than 50% of cases of trichinosis. Typically levels rise within days, peak during the third or fourth week, then gradually decline over a period of months. Trichinosis is associated with a relative eosinophilia of at least 20%, commonly exceeds 50%, and may reach a maximum of 90%. An absolute eosinophil count of 350 to 3,000/microL is associated with 75% of trichinosis cases. Twenty percent of patients have eosinophil counts of 3,000 to 8,000/microL, while few cases may have normal or near-normal values. Absolute eosinophil counts as high as 15 X 109/L have been noted.
- White blood cells are divided into granulocytes and nongranulocytes. Granulocytes include neutrophils, basophils, and eosinophils. Eosinophils are involved in the allergic reaction. They are capable of phagocytosis of antigen-antibody complexes. As the allergic response diminishes, the eosinophil count decreases. They do not respond to bacterial or viral infections.
- An elevated eosinophils count may be caused by:
- "eosinophilia", parasitic infections, allergic reactions, eczema, leukemia, or autoimmune diseases
- A decreased eosinophils count may be caused by:
- "eosinopenia" or increased adrenosteroid production
- Collect whole blood sample or use capillary blood
- Apply pressure or a pressure dressing to the venipuncture site and check the site for bleeding.
- Explain the procedure to the patient.
- Tell the patient that no fasting is required.
Indications & Uses
What To Tell Patient Before & After
MESH Terms & Keywords