Clam F207 IgE (Allergen-Specific IgE) Biomarker Testing
It measures IgE antibodies to clam to assess true shellfish allergy risk, with convenient ordering and clear results through Vitals Vault’s Quest network.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
A Clam F207 IgE test checks whether your immune system has made IgE antibodies that recognize clam proteins. This is one of the main blood tests used to evaluate the likelihood of an immediate-type shellfish allergy.
If you have had hives, lip or throat swelling, wheezing, vomiting, or rapid-onset itching after eating clam (or mixed seafood), this test can help your clinician decide how likely an IgE-mediated reaction is and what next steps make sense.
Your result is not the same thing as a diagnosis on its own. It becomes most useful when it is interpreted alongside your reaction history, other shellfish results, and sometimes a supervised oral food challenge.
Do I need a Clam F207 IgE test?
You may want a Clam F207 IgE test if you have had symptoms that start quickly after eating clam, such as hives, facial swelling, throat tightness, coughing or wheezing, lightheadedness, or repetitive vomiting. Those patterns fit an IgE-mediated reaction, and testing can help clarify whether clam is a likely trigger.
This test is also reasonable if you have avoided shellfish for a long time because of a past reaction and you want a clearer risk picture before reintroducing it. In that situation, your clinician may use IgE results to decide whether reintroduction should happen only under medical supervision.
You might also consider testing if you react to other shellfish (like shrimp, crab, or lobster) and you are trying to understand whether clam is part of the same pattern. Cross-reactivity can happen, but it is not guaranteed, so a clam-specific result can add useful detail.
If your symptoms are delayed by many hours, are mainly digestive without other allergy features, or are chronic (for example, ongoing bloating), an IgE test may not explain what is going on. Testing works best as part of clinician-directed care rather than self-diagnosis.
This is a CLIA-performed allergen-specific IgE blood test; results support clinical decision-making but do not diagnose allergy by themselves.
Lab testing
Order Clam F207 IgE testing through Vitals Vault
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
Vitals Vault lets you order Clam F207 IgE testing without needing to track down a separate lab requisition. You complete checkout, visit a nearby participating lab location, and your results are delivered to you in a clear, easy-to-review format.
If you are unsure how to interpret your number, PocketMD can help you turn the result into next-step questions for your clinician. That can include whether you should test related shellfish, whether an epinephrine plan is appropriate, and when retesting might be useful.
This approach is especially helpful when your history is mixed, such as a single reaction years ago, reactions to “seafood” dishes with multiple ingredients, or a desire to confirm whether avoidance is still necessary.
- Order online and test through a nationwide lab network
- Results you can share with your clinician for context-based decisions
- PocketMD support to plan follow-ups and retesting
Key benefits of Clam F207 IgE testing
- Helps estimate the likelihood that clam triggers immediate, IgE-mediated allergy symptoms.
- Supports safer decision-making about avoidance versus supervised reintroduction.
- Clarifies whether a past reaction labeled “shellfish” may specifically involve clam.
- Guides which related shellfish or environmental allergens may be worth testing next.
- Provides a baseline value you can trend over time if your clinician recommends retesting.
- Helps interpret skin-prick testing or mixed seafood histories when results are unclear.
- Pairs well with PocketMD to turn a number into practical next steps and questions for your visit.
What is Clam F207 IgE?
Clam F207 IgE is a blood test that measures allergen-specific immunoglobulin E (IgE) antibodies directed against clam proteins. If your immune system has become sensitized to clam, it may produce IgE that recognizes those proteins, and the test can detect and quantify that sensitization.
IgE is the antibody type involved in classic “immediate” allergic reactions. When a sensitized person eats clam, IgE on the surface of mast cells and basophils can trigger the release of histamine and other mediators. That is what can lead to fast-onset symptoms like hives, swelling, wheeze, or vomiting.
A key nuance is that sensitization is not identical to clinical allergy. You can have a measurable clam-specific IgE and still tolerate clam, and you can also have a convincing reaction history with a low or negative blood result. That is why clinicians interpret this test in context rather than using it as a stand-alone yes/no answer.
Clam vs. other shellfish
“Shellfish” includes different groups, and your immune system may react to one but not another. Some people react broadly, while others react only to certain species. Testing clam specifically can be helpful when you are trying to separate clam from other shellfish exposures in a mixed meal.
What the number represents
Your result reflects the amount of IgE in your blood that binds to clam allergen extracts used in the assay. Higher values generally correlate with a higher probability of clinical reactivity, but there is no universal cutoff that guarantees a reaction or guarantees safety.
What do my Clam F207 IgE results mean?
Low or negative Clam F207 IgE
A low or negative result means the test did not find much IgE that recognizes clam. This lowers the likelihood of an IgE-mediated clam allergy, but it does not fully rule it out, especially if your reaction history is strong. If you had symptoms immediately after eating clam, your clinician may still consider repeat testing, testing other shellfish, or a supervised oral food challenge depending on risk.
In-range results (how clinicians think about “normal”)
For allergen-specific IgE, “normal” typically means not sensitized or minimally sensitized, but labs may report results in classes or numeric ranges rather than a single optimal zone. If your result is near the detection threshold, interpretation often depends heavily on your history and whether you currently tolerate clam. When you are already eating clam without symptoms, a low-level positive may represent sensitization without clinical allergy.
High Clam F207 IgE
A higher result suggests stronger sensitization and, in many cases, a higher probability of reacting when you eat clam. It does not predict how severe a reaction would be, because severity depends on many factors beyond the IgE number. If you have a high result plus a convincing history, your clinician may recommend strict avoidance, an emergency action plan, and evaluation of related shellfish allergies.
Factors that influence Clam F207 IgE
Timing and context matter. Recent exposures do not always raise IgE quickly, and IgE levels can drift over months to years, which is why retesting is sometimes done on a clinician-guided schedule. Cross-reactivity with other shellfish proteins can contribute to a positive result even if clam is not the true trigger in your diet. People with high total IgE or multiple allergies can also have low-level positives that need careful interpretation rather than automatic avoidance.
What’s included
- CLAM (F207) IGE
Frequently Asked Questions
Do I need to fast for a Clam F207 IgE blood test?
Fasting is not usually required for allergen-specific IgE testing. If you are combining it with other labs that do require fasting, follow the instructions for the full order.
What does F207 mean on a clam allergy test?
F207 is the lab’s allergen code used to identify clam in allergen-specific IgE testing. It helps ensure the assay is measuring IgE binding to clam rather than a different food.
Can a positive clam IgE mean I will definitely react if I eat clam?
No. A positive result indicates sensitization, which increases the likelihood of clinical allergy, but it is not a guarantee. Your symptom history and, in some cases, supervised oral food challenge results are what determine whether you are truly allergic.
Can I have a clam allergy with a negative IgE test?
Yes, it can happen. False negatives are possible, and some reactions may not be IgE-mediated. If you had immediate symptoms after eating clam, discuss next steps with your clinician rather than using a negative result to self-test at home.
How is clam IgE different from IgG food tests?
IgE is tied to immediate-type allergic reactions and is the standard antibody class used for evaluating classic food allergy risk. IgG results more often reflect exposure or immune recognition and do not reliably diagnose food allergy on their own.
If I’m allergic to shrimp, will my clam IgE be positive too?
Not necessarily. Some people react to multiple shellfish due to shared proteins, while others react to only one type. Testing clam specifically can help clarify whether clam is part of your personal pattern.