Yellow Hornet I5 IgG (I5) Blood Biomarker Testing
It measures IgG antibodies to yellow hornet venom proteins to support allergy history review, with convenient ordering and Quest-based testing via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Yellow Hornet I5 IgG is a blood test that looks for IgG antibodies your immune system has made in response to yellow hornet venom proteins. It is sometimes ordered when you are trying to make sense of past sting exposures or when you and your clinician want more context alongside other allergy testing.
An IgG result does not, by itself, prove that you are “allergic” or predict how severe a future sting reaction will be. It is one data point that can support a careful review of your symptoms, timing, and any treatment you needed after a sting.
If you have had a rapid, whole-body reaction to a sting (such as trouble breathing, widespread hives, fainting, or swelling away from the sting site), you should treat that as urgent and discuss formal venom allergy evaluation with a clinician. Lab testing is meant to support clinician-directed care, not self-diagnosis.
Do I need a Yellow Hornet I5 IgG test?
You might consider this test if you have a history of hornet stings and you are trying to clarify whether your immune system has mounted a measurable response to yellow hornet venom. People often look into venom antibody testing after reactions that were confusing in the moment, especially when they are not sure what insect caused the sting.
This test can also be useful when you are comparing patterns across different venom-related tests (for example, testing multiple stinging insects) to see whether your immune response appears specific or broadly reactive. That context can matter if you spend time outdoors, have occupational exposure, or want a clearer plan for future stings.
You generally do not need an IgG venom test for a typical local sting reaction, such as pain, redness, and swelling limited to the sting site that improves over a few days. Those reactions are common and do not automatically mean you have a dangerous allergy.
If you have had symptoms that suggest anaphylaxis or a severe systemic reaction, do not rely on an IgG result to guide safety decisions. In that situation, your clinician will usually prioritize history plus venom-specific IgE testing and, when appropriate, a structured allergy workup.
This is a laboratory-developed blood test performed in a CLIA-certified lab; results support clinical assessment and are not a standalone diagnosis of venom allergy or reaction risk.
Lab testing
Order labs to measure Yellow Hornet (i5) IgG
from $105.19 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 lets you order Yellow Hornet I5 IgG testing without needing to coordinate lab paperwork on your own. After you order, you complete your blood draw at a participating lab location and receive a clear, shareable report.
If you are unsure how to interpret your result, PocketMD can help you put it into context with your symptoms, timing of exposure, and any related tests you have (or may want to add). That is especially helpful for venom testing, where the “right” next step depends heavily on your reaction history.
You can also use Vitals Vault to retest when it makes sense for your situation, or to broaden the picture with companion allergy markers so you and your clinician are not making decisions from a single number.
- Order online and complete your draw at a large national lab network
- Results you can download and share with your clinician
- PocketMD support to translate results into practical next steps
Key benefits of Yellow Hornet I5 IgG testing
- Adds objective evidence of prior immune exposure to yellow hornet venom when your sting history is unclear.
- Helps you compare responses across different stinging insects when cross-reactivity is a concern.
- Can support a more focused conversation with your clinician about which follow-up tests are most informative.
- Provides a baseline you can trend over time if you are monitoring immune response patterns.
- May help explain why you have persistent concern after a sting even when symptoms were not classic for anaphylaxis.
- Pairs well with venom-specific IgE testing when you need both “sensitization” and broader immune-response context.
- Gives you a clear, shareable lab report with optional PocketMD guidance for interpretation and next steps.
What is Yellow Hornet I5 IgG?
Yellow Hornet I5 IgG measures the amount of immunoglobulin G (IgG) antibodies in your blood that bind to yellow hornet venom proteins (often labeled as allergen “I5” in lab catalogs). IgG antibodies usually reflect that your immune system has encountered a substance before and has produced a longer-term antibody response.
For venom and allergy questions, it helps to separate “exposure” from “allergic risk.” IgG can rise after exposure and may persist, but it does not reliably predict whether you will have an immediate allergic reaction the next time you are stung. Immediate, potentially dangerous sting reactions are more closely linked to IgE (immunoglobulin E) and to the clinical story of what happened after the sting.
Because insect identification is often uncertain, clinicians sometimes look at patterns across multiple venom tests. A single positive IgG result can mean prior exposure, cross-reactivity with related venoms, or a non-specific signal, so interpretation is strongest when it is combined with your symptoms, timing, and other labs.
IgG vs IgE for sting reactions
IgE is the antibody class most associated with immediate hypersensitivity reactions, such as hives, wheezing, throat tightness, or low blood pressure shortly after a sting. IgG is more often interpreted as a marker of immune recognition or prior exposure, and it is not a substitute for venom-specific IgE when the goal is to assess allergic sensitization.
What “I5” means on a lab report
Many labs use short codes (like I5) to label specific allergens or venom sources. The code helps standardize ordering and reporting, but your clinician will focus on what the code represents—yellow hornet venom—and how the result fits your history.
What do my Yellow Hornet I5 IgG results mean?
Low Yellow Hornet I5 IgG
A low or negative result generally means the lab did not detect a meaningful IgG antibody signal to yellow hornet venom. This can happen if you have never been stung, if the sting was long ago and antibodies waned, or if your immune system did not produce a strong IgG response. A low IgG result does not rule out allergy, especially if your symptoms after a sting were immediate and systemic. If your reaction history is concerning, venom-specific IgE testing and clinical evaluation are usually more relevant.
In-range (expected) Yellow Hornet I5 IgG
Many labs report IgG results as negative/positive or in classes rather than an “optimal” range, because the clinical meaning is context-dependent. An in-range or borderline result may simply reflect minimal or uncertain immune recognition. If you had only local swelling at the sting site, this type of result often does not change management. If you had more serious symptoms, your clinician may use this as a small supporting detail while focusing on IgE testing and your clinical history.
High Yellow Hornet I5 IgG
A higher IgG level suggests your immune system has recognized yellow hornet venom and produced antibodies, which is consistent with prior exposure. It does not automatically mean you will have anaphylaxis with a future sting, and it should not be used alone to decide whether you need emergency medication or venom immunotherapy. High results can also reflect cross-reactivity among related stinging insects, especially when the exact insect is uncertain. The most useful next step is usually to review the result alongside venom-specific IgE tests and the details of your past reaction.
Factors that influence Yellow Hornet I5 IgG
Time since your last sting matters, because antibody levels can change over months to years. Repeated exposures (for example, frequent outdoor work) may increase the likelihood of a measurable IgG signal. Lab methods and reporting formats vary, so the same “class” or numeric value may not be directly comparable across different labs. Your overall immune status and certain medications or medical conditions can also affect antibody production, which is one reason results are best interpreted with your clinician.
What’s included
- Yellow Hornet (I5) Igg
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Frequently Asked Questions
Does a positive Yellow Hornet IgG mean I’m allergic to hornet stings?
Not necessarily. A positive IgG result mainly suggests prior immune exposure or recognition of yellow hornet venom. Allergy risk for immediate reactions is more closely tied to your clinical reaction history and venom-specific IgE testing.
What’s the difference between Yellow Hornet IgG and Yellow Hornet IgE?
IgE is the antibody class most associated with immediate allergic reactions after a sting. IgG more often reflects prior exposure and does not reliably predict whether you will have anaphylaxis. Your clinician may use both types of tests for context, but they answer different questions.
Do I need to fast before a Yellow Hornet I5 IgG blood test?
Fasting is usually not required for venom IgG testing. If you are bundling this with other labs (like lipids or glucose), follow the instructions for the full set of tests you ordered.
When should I test after a sting?
There is no single best day for IgG testing, but timing can affect detectability. If the sting was very recent and you are evaluating an immediate allergic reaction, clinicians often prioritize venom-specific IgE and clinical assessment. If you are testing months after a sting, IgG may still be detectable, but levels can change over time.
Can this test identify which insect stung me?
It can provide clues, but it cannot confirm the exact insect on its own. Stinging insect venoms can share similar proteins, and cross-reactivity can lead to positive results across multiple venoms. Your history, geography, and any additional venom tests help narrow it down.
Should I retest Yellow Hornet IgG?
Retesting may be reasonable if you had new stings, your exposure pattern changed, or you are trying to understand trends over time. If your main concern is severe reaction risk, discuss whether venom-specific IgE testing or a formal allergy evaluation is a better use of follow-up testing.