What is this test?
Histamine is a signaling substance that is released by mast cells and other cells in allergic reactions, but is also involved in many normal processes.
Why might it be ordered?
- In a specialized evaluation of an acute reaction or disorder in the breakdown of histamine.
- As complementary information to symptoms, tryptase, DAO and other relevant tests.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
The sample type and collection time are critical because histamine changes rapidly. Follow the laboratory instructions about food, medicines, timing and sample handling exactly; do not stop medicines on your own. Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
An increase may reflect a recent release of histamine, but a single value does not indicate the cause. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.