Quick Facts
- Sample: Whole blood (standard blood draw)
- Fasting: Not required
- Turn-around: 2–4 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Direct access — No physician referral needed; order and test on your schedule
- Comprehensive insight — Evaluates mast cell activation, histamine intolerance, and methylation status in one test
- Fast results — Receive confidential results online within 2–4 days of sample collection
- Cost-effective — More affordable than traditional specialist-ordered testing without insurance markup
- Actionable guidance — Results include interpretation support to help you understand next steps
Who Is This Test For?
- Individuals experiencing recurring hives, flushing, or unexplained allergic-type reactions
- People with suspected mast cell activation syndrome or mastocytosis
- Those investigating symptoms like headaches, GI issues, or low blood pressure after eating certain foods
- Anyone concerned about histamine intolerance or methylation imbalances
- Individuals seeking confirmation after suspected anaphylactic episodes
How It Works – Just 3 Steps
- Order online — Purchase your test without a doctor's visit or referral
- Visit a lab — Get a simple blood draw at any lab location nationwide
- Access results — View your confidential results online within 2–4 days
FAQ
Do I need to fast before this test? No, fasting is not required for the Histamine Determination Whole Blood Test.
What medications should I avoid before testing? Avoid antihistamines, allergy medications, oral corticosteroids, and H2 receptor blockers for 24 hours before your blood draw. Consult your physician before stopping any prescribed medications.
How is this different from plasma histamine testing? Whole blood histamine measures total histamine stored in blood cells, including mast cells, providing broader clinical insights and serving as a marker for methylation status.
When is the best time to get tested? For anaphylaxis evaluation, collect your sample as soon as possible after symptom onset. For chronic conditions or histamine intolerance investigation, test during symptomatic periods.
How accurate is this test? This test uses enzyme immunoassay (EIA) methodology, providing reliable quantitative results recognized by clinical guidelines from organizations like the AAAAI and NCCN.
More Details
What is the purpose of this test?
The Histamine Determination Whole Blood Test measures histamine levels to help diagnose anaphylaxis, mastocytosis, mast cell activation syndrome, and histamine intolerance (AAAAI 2024). Histamine is a chemical released from activated mast cells during allergic reactions and also functions as a neurotransmitter transmitting signals from body to brain.
Unlike plasma histamine testing, whole blood histamine reflects total histamine stored in blood cells, including that within mast cells. This test also serves as a marker for methylation status, helping identify undermethylation (elevated levels) or overmethylation (low levels). The test uses enzyme immunoassay methodology to detect histamine concentrations with high accuracy.
Who would benefit from this test?
This test is valuable for individuals experiencing recurring allergic symptoms, suspected mast cell disorders, or unexplained anaphylactic reactions. People with symptoms like flushing, hives, breathing difficulties, low blood pressure, headaches, or gastrointestinal issues after allergen exposure or food intake should consider testing.
Those investigating histamine intolerance or methylation concerns will also benefit. With 1–3% of the general population affected by histamine intolerance and diagnostic awareness improving, early testing enables proactive health management (Oxford Academic 2024). The test provides immediate access to sophisticated diagnostic capabilities typically available only through specialist referrals.
When should I order a Histamine Determination Whole Blood Test?
Order this test when you experience symptoms suggesting mast cell activation or histamine intolerance. Common symptoms include abdominal pain, dizziness, fatigue, flushing, headaches, increased heart rate, itching or hives, low blood pressure, nasal congestion, nausea, sneezing, sore throat, swelling, and trouble breathing or wheezing.
For anaphylaxis evaluation, timing is critical—collect your sample as soon as possible after symptom onset, as histamine levels increase rapidly after allergen exposure but decrease within hours. For chronic conditions or suspected histamine intolerance, test during symptomatic periods to capture elevated levels. If you've experienced reactions after consuming high-histamine foods like aged cheese, fermented products, alcohol, or certain fruits, testing can help confirm histamine intolerance.
How do I interpret the results?
- 12–127 ng/mL (Normal range): No immediate concern; monitor symptoms
- Above 127 ng/mL (Elevated): Suggests mast cell activation, allergic reactions, or histamine intolerance; consult physician and consider additional testing (tryptase, DAO activity)
- Below 12 ng/mL (Low): May indicate overmethylation; discuss methylation support with healthcare provider
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
Proper preparation ensures accurate results. Stop antihistamines, allergy medications, oral corticosteroids, and H2 receptor blockers 24 hours before your blood draw. However, consult your healthcare provider before discontinuing any prescribed medications, especially if you have chronic conditions requiring continuous treatment.
No fasting is required—you can eat and drink normally before testing. For anaphylaxis evaluation, timing is more important than preparation; collect your sample as soon as possible after symptom onset to capture peak histamine levels. The test requires a standard blood draw using a heparin tube, collected at any Walk-In Lab location nationwide.
How often should I get tested?
- Initial diagnostic evaluation: One-time test or during symptomatic episodes
- Monitoring known mast cell disorders: Every 3–6 months or as directed by physician
- Evaluating treatment response: 4–8 weeks after starting new therapy
- Histamine intolerance management: Annually or when symptoms change significantly
- Post-anaphylaxis confirmation: Within hours of symptom onset (one-time)
Testing frequency depends on your specific situation. For diagnostic purposes, one-time testing during symptomatic periods is often sufficient. If you have diagnosed mast cell disorders like mastocytosis or mast cell activation syndrome, repeat testing every 3–6 months helps monitor disease progression and treatment effectiveness.
When starting dietary modifications or new treatments for histamine intolerance, retest after 4–8 weeks to evaluate response. Always consult your healthcare provider to determine the appropriate testing schedule for your individual needs.
Why early detection matters
Early detection of histamine-related disorders enables timely intervention and significantly improves quality of life. Undiagnosed histamine intolerance can lead to chronic symptoms affecting multiple body systems, reducing daily function and overall wellbeing. With appropriate testing strategies, healthcare costs can be reduced by €242 over two years per patient through improved diagnostic accuracy and targeted treatment (NIH 2024).
For conditions like mast cell activation syndrome, early diagnosis allows implementation of trigger avoidance strategies, appropriate medication management, and dietary modifications before symptoms become severe. Clinical criteria for anaphylaxis achieve 95% diagnostic accuracy when properly applied, with biochemical markers like histamine providing valuable confirmatory evidence (AAFP 2020).
The direct-to-consumer laboratory testing market is expected to reach $9.27 billion by 2033, reflecting growing consumer demand for accessible health monitoring (BioSpace 2024). Early, convenient access to testing empowers you to take control of your health and work proactively with healthcare providers.
Related tests you may consider
Tryptase Test — Complements histamine testing for comprehensive mast cell evaluation. Tryptase levels remain elevated longer than histamine during anaphylactic reactions, making it useful when testing occurs hours after symptom onset.
Allergen Profile Mold Blood Test — Measures IgE antibodies to detect allergies to common molds. Elevated histamine levels can be associated with mold allergies, making this test relevant for individuals with histamine-related symptoms.
Histamine Determination Plasma Blood Test — Measures histamine levels in plasma, providing an additional method to evaluate histamine-related disorders such as mastocytosis, mast cell activation, or anaphylaxis. Complements the whole blood histamine test.
