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Eosinophil count in serum/plasma (qualitative screening)

Published: August 9, 2026Updated: August 16, 2026

This test checks whether your blood contains unusually high or low numbers of eosinophils, a type of white blood cell involved in allergic reactions and fighting certain infections.

Quick summary

["Eosinophils help identify possible allergic conditions or infections that may not be obvious otherwise."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
5842-0
Short code
EV Stl Cult
Synonyms
EV Stl Cult
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained weight loss. It can also help diagnose conditions like parasitic infections, certain cancers, or autoimmune disorders.

What Does the Test Measure?

This is a qualitative screening test that looks at the presence or absence of eosinophils in your blood sample. It does not provide exact numbers but helps determine if levels are significantly elevated or low.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab for analysis. The test checks the type of white blood cells in your serum or plasma.

What Are Eosinophils?

Eosinophils are a type of white blood cell that play a role in fighting off parasites and managing allergic responses. They can become too high in some diseases or conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated eosinophil counts may indicate conditions like allergic diseases (e.g., asthma, eczema), parasitic infections, certain cancers (e.g., lymphoma), or autoimmune disorders. Low eosinophil counts are less common but may suggest immune deficiencies or other blood disorders.

Short name

Eosinophil screen (serum/plasma)

Frequently asked questions

What Are Common Symptoms Linked to Eosinophil Changes?
Symptoms may include persistent itching, skin rashes, wheezing, digestive issues (like stomach pain or diarrhea), or unexplained weight loss. These symptoms can vary widely depending on the underlying cause.
How Is This Test Different from a Full Blood Count (CBC)?
While a full CBC provides detailed counts of all blood cells, this test specifically focuses on eosinophils alone. It’s often used as a quick screening tool rather than a detailed diagnostic test.
Can This Test Be Done at Home?
No, this test requires a blood sample collected by a healthcare professional. It is typically performed in a clinical lab and may not be available for at-home testing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy