Thyme F273 IgE (f273) Allergy Blood Biomarker Testing
It measures IgE antibodies to thyme to help assess allergy risk; order through Vitals Vault with Quest collection and PocketMD support.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
A Thyme F273 IgE test checks whether your immune system has made IgE antibodies that recognize thyme, a culinary herb found in many spice blends and prepared foods.
This is not a “food sensitivity” test. It is designed to support evaluation of immediate-type allergy (IgE-mediated reactions), which can show up as hives, itching, swelling, wheeze, or gastrointestinal symptoms soon after exposure.
Your result is most useful when it is interpreted alongside your symptom history and any other allergy testing your clinician recommends, because a lab value alone does not confirm how severe a reaction will be.
Do I need a Thyme F273 IgE test?
You may consider Thyme F273 IgE testing if you notice consistent symptoms shortly after eating foods seasoned with thyme or spice mixes that commonly contain it. Typical timing is minutes to a couple of hours, and symptoms can include hives, itching of the mouth or throat, facial swelling, coughing, wheezing, or sudden stomach cramps.
This test can also be helpful if you have unexplained reactions to “Italian seasoning,” marinades, soups, sausages, or restaurant meals where individual herbs are hard to identify. If you already know you react to multiple herbs or pollens, a thyme-specific IgE can help narrow down whether thyme is a likely trigger versus cross-reactivity from related plants.
You do not usually need this test for delayed symptoms that occur the next day, for chronic bloating without clear timing, or for nonspecific fatigue. In those situations, your clinician may steer you toward different evaluations.
Testing supports clinician-directed care and risk assessment, but it does not replace medical advice or an in-office evaluation if you have had severe reactions.
This is a CLIA-lab immunoassay for allergen-specific IgE; results support allergy assessment but do not diagnose allergy severity on their own.
Lab testing
Ready to order Thyme F273 IgE and get a clear baseline you can share with your clinician?
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
If you want a clear, documented thyme-specific IgE result without a long wait, you can order the Thyme F273 IgE test through Vitals Vault and complete your blood draw at a Quest collection site.
After your results post, you can use PocketMD to talk through what the number means in plain language, what companion tests may add context, and when a retest is reasonable based on your exposure and symptoms.
This approach is especially useful when you are trying to map reactions to mixed foods or spices and you want a structured next step to discuss with your clinician, rather than guessing and over-restricting your diet.
- Convenient blood draw at Quest collection sites
- Results you can download and share with your clinician
- PocketMD support for next-step questions and retest planning
Key benefits of Thyme F273 IgE testing
- Helps identify whether thyme is a plausible trigger for immediate-type allergy symptoms.
- Adds specificity when reactions happen after spice blends or restaurant meals with unclear ingredients.
- Supports safer, more targeted avoidance instead of eliminating broad categories of foods.
- Provides an objective baseline you can track if symptoms change over time or after avoidance.
- Helps your clinician decide whether additional herb, pollen, or component testing is worth adding.
- Can complement skin testing when skin tests are not available or not advisable for you.
- Pairs well with PocketMD guidance so you can interpret results in the context of your real exposures.
What is Thyme F273 IgE?
Thyme F273 IgE is a blood test that measures allergen-specific immunoglobulin E (IgE) antibodies directed at thyme (Thymus vulgaris). IgE is the antibody class involved in immediate allergic reactions, where exposure can trigger histamine release and other inflammatory signals.
The “f273” label is a laboratory code used to identify thyme as a specific allergen target in the assay. Your result reflects the amount of thyme-specific IgE detected in your blood, which can suggest sensitization (your immune system recognizes thyme) but does not automatically prove that thyme will cause symptoms every time you eat it.
Because herbs can be botanically related and share similar proteins, a positive result can sometimes reflect cross-reactivity. That is why your symptom timing, the form of exposure (raw vs cooked, small amounts vs concentrated), and other allergy history matter when interpreting the number.
Sensitization vs clinical allergy
Sensitization means you have measurable IgE to thyme. Clinical allergy means you reliably develop symptoms with exposure. You can be sensitized without having noticeable reactions, and you can have symptoms from other causes even if IgE is negative.
Why herbs can be tricky
Herbs are often consumed in small amounts and in mixtures, so exposures are hard to quantify. In addition, some people react to related plant families or pollens, which can make a single-herb IgE result more informative when it is interpreted alongside your broader allergy pattern.
What do my Thyme F273 IgE results mean?
Low Thyme F273 IgE (negative or very low)
A low result generally means the test did not detect meaningful thyme-specific IgE at the time of testing. This makes an IgE-mediated thyme allergy less likely, especially if your symptoms are not clearly immediate after exposure. However, it does not rule out non-IgE reactions, irritant effects, or reactions to other ingredients in the same meal. If your history strongly suggests allergy, your clinician may still consider additional testing or a supervised food challenge.
In-range Thyme F273 IgE (lab-specific reference interpretation)
Many labs report specific IgE on a scale where values below a defined cutoff are considered negative, and values above are considered positive with graded “classes.” If your result falls near the cutoff or in a low-positive range, it may indicate mild sensitization that only becomes clinically relevant with higher exposures or in certain contexts. The most practical way to interpret this range is to compare it with your symptom timing and reproducible exposures. Your clinician may also look for patterns across other herb or pollen IgE tests.
High Thyme F273 IgE (positive, higher level)
A higher result suggests stronger sensitization to thyme and increases the likelihood that thyme could be contributing to immediate-type reactions. Even so, the number does not reliably predict reaction severity, and it cannot tell you whether a future exposure will cause mild hives or a more serious event. If you have had systemic symptoms (trouble breathing, faintness, widespread hives), treat that as urgent and discuss an emergency plan with your clinician. High results often prompt follow-up testing for related allergens and a careful review of hidden thyme sources.
Factors that influence Thyme F273 IgE
Your result can be influenced by overall atopy (a tendency toward allergies), recent exposures, and cross-reactivity with botanically related plants or pollens. Medications do not usually “lower” specific IgE quickly, but immunomodulating therapies and long-term avoidance can change levels over time. Different labs and assay platforms may report slightly different numeric values, so trending is most meaningful when you use the same lab method. Finally, symptoms can be driven by other ingredients (other herbs, preservatives, sulfites) even when thyme IgE is positive or negative.
What’s included
- Thyme (F273) Ige
Frequently Asked Questions
Do I need to fast for a Thyme F273 IgE blood test?
Fasting is not usually required for allergen-specific IgE testing. If you are combining this with other labs (like lipids or glucose), follow the fasting instructions for those tests.
What does “f273” mean on my allergy test?
“f273” is the lab’s allergen code for thyme. It helps the lab and your clinician distinguish thyme-specific IgE from other herb or food IgE tests.
Can a positive thyme IgE prove I’m allergic to thyme?
A positive result shows sensitization, meaning your immune system recognizes thyme. Whether that translates into true allergy depends on your history—especially whether symptoms happen quickly and reproducibly after exposure.
Can I have a thyme allergy with a negative IgE result?
It is less likely, but it can happen. Some reactions are not IgE-mediated, and some people react to other ingredients in the same foods. If your reactions are concerning or severe, discuss further evaluation with your clinician.
How soon after a reaction should I test?
You can test at any time because specific IgE does not spike and disappear immediately the way some acute markers do. If you are testing to establish a baseline, doing it when your diet and exposures are typical can make interpretation easier.
How often should I retest Thyme F273 IgE?
Retesting is usually considered when your clinical situation changes—such as after a period of strict avoidance, after new reactions, or when your clinician is monitoring an allergy plan. Many people retest no more often than every 6–12 months unless there is a specific reason.
Is this the same as an IgG food sensitivity test?
No. This test measures IgE, which is associated with immediate-type allergic reactions. IgG tests are not the same tool and are not used to diagnose IgE-mediated allergy.