Eosinophil Count

CPT: 85048
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  • Absolute Eosinophil Count
  • Total Eosinophil Count

Test Includes

Enumeration of eosinophils with a cell counter

Expected Turnaround Time

Within 1 day

Related Documents

Specimen Requirements


Whole blood


Tube fill capacity

Minimum Volume

0.5 mL (500 μL for Pediatric Microtainer capillary tubes; fill tube to capacity) (Note: This volume does not allow for repeat testing.)


Lavender-top (EDTA) tube


Invert tube 8 to 10 times immediately after tube is filled at the time of collection.

Storage Instructions

Maintain specimen at room temperature.

Stability Requirements



Room temperature

1 day


3 days



Freeze/thaw cycles


Causes for Rejection

Hemolysis; clotted specimen; quantity not sufficient for analysis; specimen diluted or contaminated with IV fluid; anticoagulant other than EDTA; specimen received with plasma removed; improper labeling; transport tube with whole blood

Test Details


Usually increased in allergy, parasitic infestations, tuberculosis, brucellosis, collagen disease, Hodgkin disease, myeloproliferative diseases, and the acute hypereosinophilic syndrome; increased also in angioneurotic edema, dermatitis, thymic disorders, radiotherapy, splenectomy, convalescence from a febrile illness, and hypoadrenocorticism (Addison disease). Decreased eosinophils occurs in adrenal cortical hyperplasia (Cushing syndrome), cortisone therapy, hormone-secreting tumors, intermenstrual period, acute and chronic inflammation, and anoxia.


Automated cell counter

Additional Information

Toxocaral disease (visceral larva migrans) is a typical parasitic disease in which eosinophil counts (eosinophils >30% on differential) are usually elevated. Taylor et al1 point out, however, that up to 27% of children with toxocariasis have normal eosinophil counts. Thus, normal eosinophil counts do not rule out toxocaral disease or other parasitic infestations. The cytokine interleukin 5 appears to induce eosinophilia in patients with certain parasitic diseases.2

An important although rare cause of increased eosinophils in the peripheral blood is the acute hypereosinophilic syndrome (HES). Reported mortalities ranged from 81% to 95% in one to three years. The HES syndrome includes high peripheral WBC count, circulating early eosinophilic forms without blast cells, mental confusion, delusions, near coma, and severe cardiac symptoms. Consistently associated with a poor prognosis are WBC count ≥90,000/mm3, blast forms in blood, heart failure, and severe CNS symptoms (confusion, organic psychosis and coma). This condition may not be a true leukemic myeloproliferative disease, although concepts of HES are controversial.

Infiltrative lung diseases, in which peripheral blood eosinophils may be increased, include eosinophilic pneumonia, Löffler syndrome (often related to Ascaris infestation), and tropical eosinophilia (usually related to filariasis).3

Eosinophilic gastroenteritis may occur with blood eosinophilia.4

Eosinophilia myalgia syndrome (EMS) characterized by an eosinophil count of 2000 cells/mm3 or more and severe often incapacitating myalgia is possibly associated with the use of L-tryptophan-containing products (LTCPs). Further definition of this syndrome, causal association between LTCPs and EMS, and modifying etiologic factors/cofactors has been recommended and is being pursued by CDC.5,6 EMS is potentially fatal (Guillain-Barré like ascending polyneuropathy) with a clinical course resembling the toxic oil syndrome that was epidemic in Spain in 1981.7


1. Taylor MR, Keane CT, O'Connor P, Mulvihill E, Holland C. The expanded spectrum of toxocaral disease. Lancet. 1988 Mar 26; 1(8587):692-695. 2895221
2. Limaye AP, Abrams JS, Silver JE, Ottesen EA, Nutman TB. Regulation of parasite-induced eosinophilia: selectively increased interleukin 5 production in helminth-infected patients. J Exp Med. 1990 Jul 1; 172(1):399-402. 2193099
3. Colby TV, Carrington CB. Infiltrative lung disease. In Thurlbeck WM, ed. Pathology of the Lung. New York, NY: Thieme Medical Publishers Inc;1988:425-517.
4. Pavli P, Doe WF. The alimentary tract in disorders of the immune system. In Whitehead R, ed. Gastrointestinal and Oesophageal Pathology. Edinburgh, Scotland: Churchill Livingstone; 1989:187.
5. Centers for Disease Control and Prevention. Eosinophilia-myalgia syndrome−New Mexico. MMWR. 1989 Nov 17; 38(45):765-767. 2509886
6. Centers for Disease Control and Prevention. Eosinophilia-myalgia syndrome and L-tryptophan-containing products−New Mexico, Minnesota, Oregon and New York. MMWR. 1989 Nov 24; 38(46):785-788. 2509891
7. Kilbourne EM, Rigau-Pérez JG, Heath CW Jr, Zack MM, Falk H, Martin-Marcos M, de Carlos A. Clinical epidemiology of toxic-oil syndrome: Manifestations of a new illness. N Engl J Med. 1983 Dec 8; 309(23):1408-1414. 6633617


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
005298 Eosinophil Count 711-2 015933 Eos (Absolute) x10E3/uL 711-2
Reflex Table for Eos (Absolute)
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 000000

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