Quick Facts
- Sample: Blood draw (serum)
- Fasting: No fasting required
- Turn-around: 3-5 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Avoid painful skin pricks — no allergen exposure or reaction risk during testing
- Order online, no prescription needed — skip the doctor's office in most states
- Fast, accurate results — fluorescence enzyme immunoassay delivers reliable answers in days (Mayo Clinic Labs 2024)
- Prevent severe reactions — early detection reduces anaphylaxis risk and emergency costs
- Secure, confidential delivery — receive results directly in your secure online account
- Plan your diet safely — identify triggers and personalize nutrition with confidence
Who Is This Test For?
- Individuals experiencing symptoms after eating pistachios or pistachio-containing products
- People with suspected tree nut allergies or family history of nut allergies
- Anyone who cannot safely undergo skin prick testing due to reactions or medication use
- Those seeking confirmatory testing before starting allergen immunotherapy
- Health-conscious consumers managing multiple food sensitivities proactively
How It Works – Just 3 Steps
- Order online - Schedule your test at any certified lab location
- Get tested - Quick blood draw takes just minutes, no preparation needed
- Review results - Receive confidential results within 3-5 days
FAQ
What does this test measure? It detects IgE antibodies specific to pistachio proteins, indicating your immune system's allergic response to pistachios.
Can I eat pistachios before the test? Yes, no fasting or dietary restrictions are needed. Continue your normal diet before testing.
How accurate is this blood test? Fluorescence enzyme immunoassay (FEIA) demonstrates high sensitivity and specificity for detecting nut allergies (Mayo Clinic Labs 2024).
Will this test diagnose other nut allergies? No, this test is pistachio-specific. Consider a Tree Nut Panel for broader allergy screening.
What if my results are positive? Elevated IgE levels suggest pistachio sensitization. Consult an allergist to confirm diagnosis and create a management plan.
Do I need to stop antihistamines? Blood tests are not typically affected, but inform the lab about any medications you're taking.
More Details
What is the purpose of this test?
This Pistachio Nut Allergy IgE Blood Test measures immunoglobulin E (IgE) antibodies specific to pistachio nuts in your blood serum. When your immune system mistakenly identifies pistachio proteins—especially Pis v 1, 2, 3, 4, and 5—as harmful, it produces IgE antibodies that trigger histamine release and allergic reactions (PubMed 2017). This test uses fluorescence enzyme immunoassay (FEIA) to detect these antibodies with high accuracy, helping diagnose pistachio allergy without exposing you to potential allergens during testing.
Pistachios are popular tree nuts from the Pistacia tree, native to Central and West Asia but now cultivated globally. They appear in nut butters, trail mixes, baked goods, ice cream, sauces, vegetarian dishes, and even skincare products and hair treatments. Due to cross-reactivity, individuals with pistachio allergy may also react to cashews, almonds, walnuts, hazelnuts, and pecans.
Who would benefit from this test?
You should consider this test if you experience symptoms after consuming pistachios or pistachio-containing products. It's especially valuable for individuals with a family history of tree nut allergies or those who've experienced reactions to other nuts. This blood test provides a safer alternative if you cannot undergo skin prick testing due to severe reactions, eczema, or medication contraindications like antihistamine use.
Healthcare providers also recommend this test for pre-immunotherapy evaluation, confirmatory diagnosis when skin testing is inconclusive, and for children or adults managing multiple food allergies. Tree nut allergies affect approximately 7% of nut allergy cases in the United States, and pistachio allergy prevalence has increased significantly over the past decade (PubMed 2017, American Pistachio Growers 2021).
When should I order a Pistachio Nut Allergy IgE Blood Test?
Order this test when you experience allergic symptoms within minutes to a few hours after eating pistachios. Common reactions include tingling or swelling around the mouth, hives, eczema, abdominal pain, nausea, vomiting, diarrhea, congestion, wheezing, or lightheadedness. These symptoms indicate your immune system may be producing IgE antibodies against pistachio proteins.
Seek immediate medical attention if you experience anaphylaxis symptoms: rapid pulse, swollen throat making breathing difficult, severe dizziness, loss of consciousness, or dangerously low blood pressure. After emergency treatment, this test helps confirm the trigger allergen. You should also order testing before introducing pistachios to children with family allergy history or when multiple unexplained allergic reactions occur after eating mixed nut products.
How do I interpret the results?
Results report your pistachio-specific IgE antibody levels measured in kU/L (kilounits per liter). Higher levels indicate greater immune sensitization to pistachio proteins:
< 0.35 kU/L (Negative – no sensitization detected)
- Meaning: Pistachio allergy unlikely
- Action: Consult provider if symptoms persist
0.35–0.69 kU/L (Low positive – mild sensitization)
- Meaning: Possible allergy
- Action: Discuss with allergist for clinical correlation
0.70–3.49 kU/L (Moderate positive – moderate sensitization)
- Meaning: Probable allergy
- Action: Avoid pistachios and consider follow-up testing
3.50–17.49 kU/L (High positive – strong sensitization)
- Meaning: Allergy confirmed
- Action: Strict avoidance; carry epinephrine if prescribed
≥ 17.50 kU/L (Very high positive – very strong sensitization)
- Meaning: Severe allergy likely
- Action: Allergen consultation essential for management plan
Positive results indicate your immune system recognizes pistachio proteins, but clinical correlation with your symptoms is necessary. False positives can occur, especially with very low positive levels. Always review results with an allergist or healthcare provider who can interpret findings in the context of your medical history and symptoms.
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
No fasting or special preparation is required before this blood test. You can eat and drink normally, including consuming pistachios if you haven't experienced severe reactions. Continue taking your regular medications, though you should inform the lab if you're using antihistamines, as they may affect some allergy assessments.
The blood draw is performed via standard venipuncture into serum gel or red-top tubes. The specimen is centrifuged to separate serum, which is then refrigerated or frozen if testing is delayed. Your sample is shipped to a certified laboratory under cold chain protocols and analyzed using fluorescence enzyme immunoassay (FEIA) (Mayo Clinic Labs 2024).
How often should I get tested?
Testing frequency depends on your clinical situation and allergy management goals:
- Initial diagnosis with symptoms: Once, followed by allergist consultation
- Monitoring during immunotherapy: Every 6–12 months as recommended by allergist
- Children showing possible tolerance development: Every 1–2 years with allergist guidance
- Stable, confirmed allergy: Retest only if symptoms change or accidental exposure occurs
- Pre-challenge testing before reintroduction: As directed by allergist before supervised food challenge
Why early detection matters
Early identification of pistachio allergy significantly reduces your risk of severe reactions, including potentially life-threatening anaphylaxis. Knowing your specific trigger allows you to avoid accidental exposure from hidden sources like sauces, baked goods, and cross-contaminated products. This knowledge lowers emergency healthcare costs and improves your quality of life (American Pistachio Growers 2021).
Timely diagnosis enables you to work with a nutritionist to maintain a balanced diet while safely avoiding pistachios and potentially cross-reactive nuts. You'll learn to read ingredient labels effectively, recognize pistachio derivatives in non-food products like cosmetics, and develop emergency action plans including carrying epinephrine auto-injectors if prescribed. Early detection also supports better management for children, preventing delayed growth or nutritional deficiencies from unnecessary dietary restrictions.
Related tests you may consider
Tree Nut and Peanut Allergy Panel — Screens for IgE antibodies to multiple tree nuts including cashew, almond, hazelnut, pecan, coconut, peanut, and sesame seed for comprehensive allergy profiling.
Total IgE Test — Measures overall IgE antibody levels to evaluate atopy or assess whether you have multiple allergic sensitivities.
Cashew Nut Allergy IgE Test — Important companion test since pistachio and cashew allergies frequently co-occur due to botanical similarity and protein cross-reactivity.
