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Differences Between Food Sensitivity and Allergy Tests
Food sensitivity and allergy tests differ significantly, with food allergy tests focused on immediate, severe reactions mediated by IgE antibodies, and food sensitivity tests primarily identifying delayed immune responses mediated by IgG antibodies. Food allergy tests are generally more reliable and straightforward, while food sensitivity tests usually need to be used in conjunction with other diagnostic methods.
Allergies and sensitivities are often talked about interchangeably, but there are some pretty big differences—both in the seriousness of the reaction, and how allergy testing for food sensitivities and allergies is conducted. It’s important to understand that an allergy is an immune response, while sensitivities are a more muted or delayed reaction with a more complex cause.
For this reason, the way that the tests function is completely different. In fact, allergic reactions are relatively easy to diagnose, and experienced allergists in Sydney can reach a conclusion in as little as a day. Testing for food sensitivities, on the other hand, can take weeks, and the process is much more complex.
At Allergy Testing Sydney, we treat and diagnose both sensitivities and allergies. If you’re having issues with gluten, lactose, or any other allergen, contact our Sydney allergists today to discuss how we can help make your life more manageable, whether that’s through food sensitivity testing Sydney, food allergy blood tests, or comprehensive treatment plans.
What is food allergy testing?
Allergy testing for food allergies can be as simple as a blood test and a skin prick test. These blood tests, undertaken in response to adverse reactions to specific foods, can identify IgE, a type of antibody mistakenly produced by the immune system in response to an allergen. IgE binds to certain cells in the skin, lungs, and digestive tract, and is easily identifiable through blood tests.
What is a food sensitivity test?
Food sensitivities can also be identified through bloodwork, although this is often harder to interpret. These blood tests seek to identify IgG—an antibody that the immune system produces when it encounters a food it identifies as potentially harmful. This reaction is typically less immediate and severe than that of an IgE-mediated food allergy, and the presence of IgG response doesn’t always indicate an adverse reaction. In some cases, it might simply reflect exposure to that food without causing symptoms.
These tests are commonly used to identify food sensitivities, but their accuracy and interpretation are debated. Unlike IgE-based tests for allergies, IgG testing doesn’t necessarily correlate with clinically significant reactions and should be used alongside other methods, like an elimination diet, to determine an appropriate treatment plan.
Key differences between food sensitivity and allergy tests:
| Aspect | Food Sensitivity Test | Food Allergy Test |
| Purpose | Identifies delayed immune responses to foods (e.g., digestion issues, mild reactions). | Detects immediate immune responses (IgE-mediated) to specific food allergens. |
| Reaction Type | Non-IgE mediated reactions, often mild and delayed (e.g., bloating, fatigue). | IgE-mediated reactions, often severe and immediate (e.g., anaphylaxis). |
| Common Symptoms | Bloating, headaches, fatigue, digestive discomfort, skin rashes. | Hives, swelling, difficulty breathing, anaphylaxis, throat tightness. |
| Test Method | Blood test (measuring IgG antibodies), elimination diets, skin prick tests. | Skin prick tests, blood tests (measuring IgE antibodies). |
| Time of Reaction | Hours to days after consumption. | Minutes to hours after consumption. |
| Treatment Approach | Elimination of trigger foods, managing symptoms. | Strict food avoidance, emergency epinephrine (EpiPen) for severe reactions. |
| Test Results | Results show varying levels of sensitivity to foods, harder to interpret. | Clear results that show specific allergens triggering IgE responses. |
| Severity of Symptoms | Chronic, less severe symptoms, often manageable. | Immediate, potentially life-threatening reactions. |
| Examples of Symptoms | Digestive issues, fatigue, bloating, headaches. | Anaphylaxis, hives, throat swelling, severe breathing difficulty. |
| Test Reliability | Some debate about the accuracy of tests. At home food sensitivity tests have gained some popularity, but these are not FDA-approved, due to issues with reliability. | Generally considered reliable for identifying true food allergies. |
When to consider food allergy vs food sensitivity test Australia:
There can be overlapping symptoms between food allergies and food sensitivities, although the way they function differs entirely. For this reason, it can be hard to know which is which. In general, food allergies are more serious. While those with food sensitivities may be able to tolerate small amounts of the trigger food, those with allergies can expect a reaction even from very small doses.
The hallmark of non-IgE mediated food allergies is the delayed onset of symptoms, which can make it challenging to pinpoint the culprit food. The most common symptoms include:
- Vomiting and Diarrhoea: This can sometimes be severe, leading to dehydration.
- Abdominal Pain and Bloating: General discomfort in the gut.
- Reflux and Food Refusal: Particularly in infants and young children.
- Poor Growth: Ongoing inflammation can affect nutrient absorption.
- Eczema: While also a symptom of IgE-mediated allergies, it can be a feature of non-IgE reactions, especially in young children.
Common Food Triggers for Non-IgE Mediated Food Allergies:
- In Children: Cow’s Milk, Soy, Wheat, Eggs.
- In Adults: Fish and Shellfish.
Diagnosing non-IgE mediated food allergies can be a process of elimination. Most diagnostic approaches involve:
- Clinical History: A discussion with a healthcare professional about the symptoms and their timing in relation to food intake.
- Elimination Diet: Removing the suspected trigger food to see if the symptoms resolve.
- Reintroduction/Food Challenge: Reintroducing the food under medical supervision to confirm it as the cause of the reaction. This is considered the “gold standard” for diagnosis.
If food allergy testing confirms a reaction, then the primary management strategy is strict avoidance of the identified trigger food. Nutritional counselling from a dietitian is often recommended, especially for children on restricted diets.
Limitations of allergy and food sensitivity testing:
It might be tempting to start with the widely available food sensitivity testing at home, but it’s worth knowing that these tests are not considered to be a reliable way to test for food sensitivity. Even the best at home food sensitivity test is not FDA-approved.
Additionally, the official stance of professional medical organisations such as the Australasian Society of Clinical Immunology and Allergy (ASCIA), the American Academy of Allergy, Asthma & Immunology (AAAAI), and the European Academy of Allergy and Clinical Immunology (EAACI) is that IgG testing should not be used to diagnose food sensitivities or allergies.
Regardless of what the results are, you’ll likely still need to see an allergist, who will likely recommend a combination of a food sensitivity blood tests and an elimination diet to get to the bottom of your reactions.
Additionally, these tests are not designed to test for food allergies, which require specific tests like IgE blood tests or skin prick testing conducted by a professional. To truly understand your body’s reactions, it’s best to work with a qualified allergist who can guide you through the process of diagnosing and managing food sensitivities. If you are looking to test food sensitivity, it’s crucial to have a healthcare provider involved to interpret the results and recommend a suitable course of action.
Consulting Allergy Testing Sydney:
If you’re experiencing the impact of allergies and want to find out more, you might benefit from contacting us here at Allergy Testing Sydney. From food allergy testing Sydney to food sensitivity blood tests, we can help you discover what’s causing your discomfort and direct you where to go next to find some relief.
Our clinic is led by medical director Dr Richard Stephen Baker. Dr Baker is passionate about helping Sydney locals discover and better treat their allergies and has been at the forefront of sublingual treatment, improving the lives of hundreds of patients.
