If there are reasons to suspect that you might be affected by allergies, you should certainly see a doctor who might decide to refer you to allergy testing. Allergy testing is a fairly common practice in the UK and it can be undertaken in a variety of ways with a specialist choosing the one most suitable for you. A vast majority of allergy diagnosis methods will provide you with more than just a simple yes or no answer – it will clearly single out the specific triggers that you react to. With this knowledge, it will be significantly easier for you to avoid those triggers and prevent allergic reactions.
What’s on this page?
In this article, we will discuss some of the most commonly employed allergy diagnosis methods.
Skin prick test – the most common allergy diagnosis method
Skin prick test is undoubtedly the most common form of allergy diagnosis. This test is used to confirm the presence of numerous different allergies regardless of the exact nature of the triggers. As such, skin prick test can simultaneously test for, let’s say, food allergies, pollen, pet hair and many other, and with exceptional reliability. This method of allergy diagnosis is suitable for children and adults alike and is usually administered to the forearm or the upper back in some situations like testing for an exceptionally large range of triggers or in situations where several strong reactions are expected.
Skin prick test involves making small painless punctures to the area of the skin and administering precisely limited amounts of common allergens with each of them being precisely mapped on the matrix of punctures. In order to keep track of it, the doctor will usually mark the punctures with a code and thus reliably track which allergens cause reaction of what intensity.
If you experience an allergic reaction to any of the given allergens used in the test, the patch of skin where the allergen has been administered will become red, raised and itchy. The specialist conducting the test will carefully monitor the reaction, informing you about your identified triggers and the severity of reaction to each of them.
Testing for allergies through a blood test
Another commonly used method of diagnosing allergies involves taking a blood sample and checking the levels of Immunoglobulin E antibodies (often abbreviated to IgE) which are produced by the human body in the event of an allergic reaction. The sample should be taken during the time of the suspected allergic reaction and then sent to a laboratory where it will be analysed by a specialist. The results will usually be available within a week or two.
However, the downside of this diagnosis method is that it cannot determine the severity of an allergic reaction, unlike skin prick test, so it cannot help the doctor in assessing the risk of anaphylaxis.
Patch test for diagnosing allergic skin reactions (eczema and dermatitis)
Patch allergy tests are commonly employed by dermatologist when the allergic reaction primarily manifests through a skin reaction such as eczema or dermatitis. This diagnosis method involves applying small aluminium discs coated with precisely measured amount of triggers directly to the skin, most commonly on the back.
Ideally, the area of the skin where the test is applied should be free from eczema or other problems and dermatologist might even advise you to temporarily suspend the use of topical medications or steroid tablets as they can distort the end results.
Once applied, the aluminium discs should remain in place for a period of 48 hours, after which the doctor will remove them and assess the results. As such, patch test is very similar to skin prick test, with the main difference being that it is developed specifically for diagnosing allergies that cause a skin reaction.
Oral food challenge (OFC) allergy test
If both skin prick and blood tests have produced inconclusive results, then the doctor might recommend oral food challenge, also known as OFC test. However, the biggest downside of OFC is that it can, in some cases, cause a serious reaction which will require immediate medical attention. Precisely because of this, OFC test is usually carried out at a hospital with the relevant equipment and trained staff nearby.
This test is rather straightforward – it involves the patient consuming the potential food allergen in edible form in exponentially larger doses until a reaction is provoked. Once allergic reaction occurs, the test will be stopped immediately.
There are several variations of the OFC:
Open food challenge
Open food challenge is considered to be the most basic version of this test, where both doctor and the patient are aware of what allergen is being tested at which moment. It is applied in those scenarios where the patient’s potential anxiety is unlikely to have any measurable effect.
Single-blind food challenge
This variation of the OFC is used in those situations where there is suspicion that patient’s psychosomatic response to anxiety might distort the results. Thus, only the doctor will know what allergen is being tested at which point, while the patient will have no information before the end of the test.
Double-blind or placebo-controlled food challenge
For most objective results, the doctor will recommend conducting a double-blind placebo-controlled food challenge. This variation of the OFC test is designed in such a way that neither doctor nor the patient is aware of the exact nature of the allergens administered at any given time. On top of that, placebo is also introduced, to ensure maximum objectivity.
Can I check what I’m allergic to without visiting a doctor?
While it is not advised to rely on DIY allergy diagnosis methods alone, you can still try to identify your common triggers so the doctor will have easier time when conducting the test, possibly using fewer samples. In order to do this, you should keep a symptom diary that should be filled in every time you experience an allergic reaction. To provide you with relevant information, your diary should include the following information:
- Detailed list of all foods and drinks you consumed
- Times when you consumed said foods or drinks
- List of activities you were participating in at the time
- Exact nature of symptoms and their duration
- Treatment you used (if any)
- The efficiency of the treatment used (if any)
The goal of this kind of noting details about your allergic reactions is to highlight any possible relations between foods and drinks you consume and your allergic response, while also providing information about the severity of the condition and most promising treatment methods. This information can be very valuable to your doctor when devising your diet plan and prescribing treatment. In addition to this, you might be able to notice some common allergens that you react to so you can avoid them in the future.
