Velvet Grass (G13) Specific IgE Biomarker Testing
It measures IgE antibodies to velvet grass pollen to help assess allergy sensitization, with easy ordering and Quest-based lab access via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
A Velvet Grass (G13) IgE test is an allergy blood test that looks for immunoglobulin E (IgE) antibodies your immune system has made to velvet grass pollen.
This test does not “prove” you have symptoms from velvet grass on its own. Instead, it helps answer a more practical question: are you sensitized to this specific grass pollen in a way that could match your seasonal symptoms?
If you are trying to sort out spring or summer congestion, itchy eyes, wheezing, or flares of eczema, a targeted IgE result can help you and your clinician connect timing, exposures, and next steps.
Do I need a Velvet Grass G13 IgE test?
You may want this test if your symptoms reliably worsen during grass pollen season, especially when you are outdoors or when windows are open. Common patterns include sneezing, runny or stuffy nose, post-nasal drip, itchy or watery eyes, cough, chest tightness, or asthma symptoms that flare at certain times of year.
This test can also be useful if you already know you have “grass allergy” but you want more detail about which grasses you are sensitized to. That detail can matter when you are deciding whether to focus on avoidance strategies, consider allergy medications more proactively during peak season, or discuss allergen immunotherapy (allergy shots or tablets) with an allergist.
You might also consider testing if skin-prick testing is not practical for you, such as when you cannot stop antihistamines, you have extensive eczema, or you prefer a blood draw approach.
Testing is most helpful when it supports clinician-directed care and is interpreted alongside your symptoms and exposure history, rather than used as a stand-alone diagnosis.
This is typically a CLIA-validated allergen-specific IgE blood assay; results indicate sensitization risk and should be interpreted with your clinical history, not used as a sole diagnosis.
Lab testing
Order labs to measure Velvet Grass (g13) IgE
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 lets you order a Velvet Grass (G13) specific IgE test without needing a separate doctor visit just to obtain the lab order. You can choose a single targeted allergen test when you have a clear seasonal trigger in mind, or you can pair it with related allergens if your symptoms are harder to pin down.
After your results post, you can use PocketMD to walk through what “negative,” “low positive,” or “high positive” means for you, and what follow-up questions to bring to your clinician. That can include whether a broader grass or regional pollen panel would add value, or whether your pattern fits better with non-allergic rhinitis.
If you are tracking symptoms over time, Vitals Vault also makes it straightforward to reorder and compare results, especially when you are evaluating how well avoidance steps or treatment changes are working across seasons.
- Order online and complete testing through a national lab network
- PocketMD helps you interpret results and plan next steps
- Easy re-testing for seasonal trend tracking
Key benefits of Velvet Grass G13 IgE testing
- Helps confirm whether velvet grass pollen sensitization matches your seasonal symptom pattern.
- Supports more targeted avoidance planning when outdoor exposure triggers flares.
- Clarifies whether “grass allergy” is likely to be one driver versus multiple pollen triggers.
- Provides objective data when skin testing is not feasible or you cannot stop antihistamines.
- Helps guide conversations about immunotherapy by documenting specific pollen sensitization.
- Can be combined with other specific IgE tests to map cross-reactive or co-existing allergies.
- Gives a baseline you can compare over time when symptoms change across seasons.
What is Velvet Grass G13 IgE?
Velvet grass is a type of grass whose pollen can act as an airborne allergen. The Velvet Grass (G13) IgE test measures allergen-specific IgE antibodies in your blood directed against velvet grass pollen proteins.
IgE is the antibody class involved in immediate-type allergic reactions. If you are sensitized, your immune system can bind velvet grass pollen with IgE, which can trigger release of histamine and other mediators. That process is what can lead to symptoms such as sneezing, nasal congestion, itchy eyes, hives, or asthma flares.
A key point is that this test measures sensitization, not symptom severity. Some people have detectable IgE but minimal symptoms, while others have significant symptoms with modest IgE levels. Your timing of symptoms, local pollen counts, and other allergies often determine how meaningful the number is for you.
Specific IgE vs total IgE
Specific IgE targets one allergen (here, velvet grass). Total IgE is a broad measure of overall IgE in your bloodstream and can be elevated for many reasons, including other allergies, eczema, infections, or rarely immune conditions. A normal total IgE does not rule out a specific pollen allergy, and an elevated total IgE does not tell you which allergen is responsible.
How this differs from skin testing
Skin-prick testing measures an immediate skin response to allergen extracts, while a blood test measures circulating IgE antibodies. Both can be clinically useful. Blood testing is often preferred when you cannot stop antihistamines, have extensive skin disease, or want a simple blood draw without multiple skin pricks.
What do my Velvet Grass G13 IgE results mean?
Low or negative Velvet Grass (G13) IgE
A low or negative result means velvet grass sensitization is less likely, especially if the test is truly negative. If you still have strong seasonal symptoms, this can point toward other pollens (other grasses, trees, weeds), indoor allergens, or non-allergic rhinitis. It can also happen if your symptoms are driven by irritants (smoke, fragrances) rather than IgE-mediated allergy. If suspicion remains high, your clinician may suggest testing additional grass pollens or doing skin testing for a broader look.
In-range results (how to think about “normal”)
For allergen-specific IgE, “normal” usually means not sensitized or below the lab’s positivity threshold. If your result is in this range and your symptoms are mild or inconsistent, velvet grass is unlikely to be a major trigger. If your symptoms are persistent, the next step is often to test other likely allergens based on your geography and seasonality. Your clinician may also consider whether you have chronic sinus issues, reflux-related cough, or asthma triggers unrelated to allergy.
High Velvet Grass (G13) IgE
A higher result suggests you are sensitized to velvet grass pollen and that exposure could plausibly contribute to symptoms. The higher the level, the more likely it is to be clinically relevant, but it still needs to match your real-world pattern (for example, symptoms during grass pollen season or after mowing). If you have asthma, a meaningful pollen sensitization can be important because seasonal exposure may worsen control. High results often prompt a broader allergy plan: environmental steps, medication timing, and discussion of immunotherapy when symptoms are significant.
Factors that influence Velvet Grass (G13) IgE
Your result can be influenced by cross-reactivity among grass pollens, meaning IgE may recognize similar proteins across different grasses. Timing matters too: IgE levels can fluctuate over months and years, and your symptoms may vary depending on pollen counts and weather. Age, co-existing allergic conditions (like eczema), and overall atopic tendency can affect the likelihood of positive results. Medications like antihistamines do not typically suppress blood IgE levels the way they can affect skin testing, but immune-modifying therapies and immunotherapy over time may change patterns.
What’s included
- Velvet Grass (G13) Ige
Similar tests to consider
Frequently Asked Questions
What does the Velvet Grass (G13) IgE test measure?
It measures allergen-specific IgE antibodies in your blood directed against velvet grass pollen. This indicates whether your immune system is sensitized to that pollen and whether it could be a plausible trigger when exposure matches your symptoms.
Do I need to fast before a velvet grass IgE blood test?
Fasting is not usually required for allergen-specific IgE testing. If you are having other labs drawn at the same visit, follow the fasting instructions for those tests.
Can antihistamines affect my Velvet Grass IgE result?
Antihistamines can interfere with skin-prick testing, but they generally do not lower allergen-specific IgE levels measured in blood. If you are on immune-modifying medications or receiving immunotherapy, ask your clinician how that might affect interpretation over time.
If my Velvet Grass IgE is positive, does that mean I will definitely have symptoms?
Not necessarily. A positive result shows sensitization, but symptoms depend on exposure level, pollen counts, other allergies, and your airway sensitivity. The result is most meaningful when it lines up with your seasonal timing and real-world triggers.
What if my result is negative but I still have seasonal allergies?
A negative result makes velvet grass less likely as the cause, but it does not rule out other pollens or indoor allergens. Many people need a broader set of specific IgE tests (other grasses, weeds, trees, dust mites, pets) or skin testing to identify the main triggers.
How often should I retest velvet grass specific IgE?
Retesting is usually not needed for routine seasonal allergies unless your symptoms change significantly, you are evaluating response to immunotherapy, or your clinician is updating your allergy profile. When retesting is done, it is often spaced months to a year or more apart, since IgE patterns typically change gradually.
Is this the same as a food allergy test?
No. This test is for an inhalant pollen allergen (velvet grass). Food allergy testing uses different allergen targets (for example, shellfish or yeast) and should be interpreted with food-related reaction history, since false positives can occur without true clinical allergy.