Cashew Nut F202 IgE With Reflex to Components Biomarker Testing
It measures IgE antibodies to cashew and, if positive, tests key components to refine risk—order through Vitals Vault with Quest lab access.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
This test looks for IgE antibodies your immune system may make to cashew (F202). If the screening result is positive or above the lab’s reflex threshold, the lab automatically runs “component” testing to see which specific cashew proteins your IgE is reacting to.
That extra layer matters because not all cashew sensitization behaves the same way. Component results can help your clinician weigh whether a positive IgE is more likely to match true allergy versus cross-reactivity, and how cautious you need to be with exposure.
A blood test cannot predict the exact severity of a future reaction on its own. Your history of symptoms, timing, and any prior reactions still drive the safest plan.
Do I need a Cashew Nut F202 IgE With Reflex to Component test?
You may want this test if you have symptoms after eating cashew or foods that may contain cashew, such as hives, lip or tongue swelling, throat tightness, vomiting, coughing, wheezing, or lightheadedness. It can also be useful if you had a reaction to a mixed nut product and you are trying to identify which nut is most likely responsible.
This test is also commonly used when you have eczema (atopic dermatitis), asthma, or allergic rhinitis and you are evaluating possible food triggers, especially if you have a history of other tree nut allergies. If you have never eaten cashew but you have positive tests to other nuts, your clinician may use component results to help decide whether supervised introduction or strict avoidance is more appropriate.
You generally do not need IgE testing as a “screening” test without symptoms or a clear reason, because false positives can lead to unnecessary food avoidance. Testing works best when it is used to answer a specific clinical question and is interpreted alongside your reaction history, not as a stand-alone diagnosis.
This is a laboratory-developed test performed in a CLIA-certified lab; results support clinical decision-making but do not diagnose allergy by themselves.
Lab testing
Order labs to measure Cashew Nut (f202) IgE with Reflex to Component
from $19.99 at Quest Diagnostics
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Get this test with Vitals Vault
Vitals Vault makes it straightforward to order cashew-specific IgE testing with reflex to components when you want a clearer picture than a single “positive/negative” number. You can schedule your blood draw through a national lab network and view results in one place.
Once your results are back, PocketMD can help you turn the numbers into next steps to discuss with your clinician, such as whether the pattern fits likely true cashew allergy, whether additional tree nut testing could clarify your risk, and when retesting might be reasonable.
If you are tracking changes over time (for example, after a period of avoidance or as part of an allergist-directed plan), Vitals Vault also helps you keep results organized so you can compare trends rather than relying on memory.
- Order online and complete your blood draw at a participating lab location
- PocketMD guidance to help you prepare questions for your clinician
- Clear, shareable results for follow-up care and retesting
Key benefits of Cashew Nut F202 IgE testing
- Helps determine whether your immune system is sensitized to cashew (IgE-mediated allergy pathway).
- Reflex component testing can distinguish higher-risk protein patterns from more ambiguous sensitization.
- Supports safer decisions about avoidance, label vigilance, and whether supervised introduction is appropriate.
- Adds context when skin testing is unavailable, inconclusive, or not advisable for you.
- Helps your clinician interpret a positive result in the setting of other tree nut allergies and possible cross-reactivity.
- Provides a baseline to monitor changes over time when retesting is clinically indicated.
- Keeps your cashew IgE and component results together in one report for easier follow-up with PocketMD and your care team.
What is Cashew Nut F202 IgE With Reflex to Component?
Cashew Nut F202 IgE is a blood test that measures allergen-specific immunoglobulin E (IgE) directed against cashew extract. A higher result means your immune system has made IgE antibodies that recognize cashew proteins, which can be associated with immediate-type allergic reactions.
“Reflex to component” means the lab may automatically run additional tests for individual cashew proteins (components) when the initial cashew IgE result meets the lab’s criteria. Component-resolved diagnostics can improve interpretation because different proteins are associated with different likelihoods of true clinical allergy.
This test does not measure intolerance, sensitivity, or delayed reactions that are not IgE-mediated. It also does not replace an in-office evaluation, and it cannot by itself determine whether you will have anaphylaxis.
What does IgE actually represent?
IgE is an antibody involved in allergic reactions. If you are sensitized, IgE binds to allergy cells (mast cells and basophils). When you are exposed to the allergen again, those cells can release histamine and other mediators that cause symptoms.
Why components matter for cashew
Cashew contains multiple proteins. Some are more stable and more strongly linked to true allergy, while others may reflect cross-reactivity or less clinically meaningful sensitization. Component results can help your clinician interpret whether a positive extract IgE is more likely to match real-world reactions.
How this fits with other testing
Your clinician may combine this blood test with your symptom history, other nut IgE tests, and sometimes skin prick testing. In selected cases, an oral food challenge in a supervised setting is used to confirm whether you can tolerate cashew.
What do my Cashew Nut F202 IgE With Reflex to Component results mean?
Low cashew-specific IgE
A low or undetectable cashew IgE result makes an IgE-mediated cashew allergy less likely, especially if you have eaten cashew without symptoms. If you had a convincing reaction, a low result does not fully rule out allergy because timing, lab variability, and rare non-IgE mechanisms can complicate interpretation. Your clinician may consider repeat testing, skin testing, or a supervised challenge depending on your history.
In-range (negative) or clinically consistent results
For allergen-specific IgE, “optimal” usually means the result matches your real-world experience. If you have no symptoms with cashew and your IgE is negative, that is reassuring. If you have symptoms and the test is positive with components that fit true allergy, the result can support a clear avoidance and emergency plan discussed with your clinician.
High cashew-specific IgE and/or positive components
A higher cashew IgE level increases the likelihood of true sensitization, but it does not automatically predict reaction severity. Component positivity can add important detail, because some component patterns are more strongly associated with clinical allergy than extract testing alone. If your results are high, your next step is usually a clinician-guided plan for avoidance, cross-contact precautions, and whether you should carry epinephrine based on your history.
Factors that influence cashew IgE results
Your result can be influenced by age, eczema severity, and the presence of other allergies (including other tree nuts). Recent exposures do not reliably “spike” IgE the way an infection might change other labs, but IgE can change over months to years. Lab methods and reporting thresholds vary, so comparing results is most meaningful when you use the same lab and interpret trends with your clinician. Medications like antihistamines generally do not affect blood IgE results (they can affect skin testing).
What’s included
- Cashew Nut (F202) Ige
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Frequently Asked Questions
Do I need to fast for a cashew IgE blood test?
No. Fasting is not required for allergen-specific IgE testing, so you can usually eat and drink normally unless you are combining it with other labs that require fasting.
What does “reflex to component” mean on my order?
It means the lab starts with cashew extract IgE (F202). If that result meets the lab’s reflex rule (often a positive or above a set threshold), the lab automatically runs additional tests for individual cashew proteins (components) to refine interpretation.
Can this test tell how severe my reaction will be?
Not by itself. Higher IgE and certain component patterns can increase the likelihood of true allergy, but severity depends on many factors, including your past reactions, asthma control, amount ingested, and co-factors like exercise or illness. Your clinician uses the lab result as one piece of the risk assessment.
If my cashew IgE is positive, does that mean I must avoid all tree nuts?
Not necessarily. Some people are allergic to one nut and tolerate others, while others react to multiple nuts or avoid them due to cross-contact risk. Your clinician may recommend testing other nuts, reviewing ingredient-label practices, and deciding whether selective avoidance or broader avoidance is safest for you.
How is this different from a skin prick test?
A skin prick test measures an immediate skin response to an allergen extract, while this blood test measures allergen-specific IgE in your bloodstream. Blood testing can be helpful when skin testing is not available or when skin conditions or medications complicate skin testing, but both tests still need your symptom history for correct interpretation.
When should I retest cashew IgE?
Retesting is usually considered when it could change management, such as reassessing risk after a period of avoidance or when an allergist is monitoring whether an allergy may be resolving. Many clinicians wait months to a year or more, because IgE trends typically change gradually. Your clinician can recommend timing based on age, history, and prior results.
Can I have a negative test and still react to cashew?
Yes, although it is less common for immediate IgE-mediated allergy. A negative result makes IgE-mediated cashew allergy less likely, but testing is not perfect and symptoms can have other causes. If you had a convincing reaction, do not reintroduce cashew without clinician guidance.