Allergy testing
Allergy affects a lot of people in the UK. About 1 in 4 adults, 1 in 6 teenagers and 1 in 10 children are affect by allergy. That’s quite a lot, isn’t it? But almost half of all people with allergy symptoms have not had a diagnosis from a doctor. And even fewer people know what allergen or allergens they react to. Some people might not even be aware that the symptoms they are experiencing are caused by an allergy. Let’s take a look at allergy and allergy testing.
What is allergy?An allergic reaction takes place when your immune system mistakenly identifies a harmless substance as a threat and takes excessive defensive action. Substances that trigger an allergic reaction are called allergens.
Allergy may affect your family life, work performance, social activities and more. Allergy symptoms can affect your sleep, which can impact your energy levels during the day. And ultimately some allergies can even be life-threatening.
Symptoms of an allergic reactionThere are many types of allergies. The severity of symptoms for each type can vary, and you may experience your symptoms differently from other people with allergy. Some of the symptoms of an allergic reaction might include:
Pollen
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House dust mite
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Pet dander
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Insect venom
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Mould spores
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Food
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Read more about the different types of allergy
As you can see from the table above, some of the symptoms from a reaction to one type of allergen are similar to those caused by another. It can be confusing to know what’s what.
Additionally, there can be other causes for your symptoms. For example, foods can cause unpleasant symptoms, such as bloating, nausea or diarrhoea. These symptoms can have many different causes, allergy being one of them. It is important to note that food allergy is different to food intolerance. Food intolerance is when your body is unable to process certain foods.
Read more about food allergy and food intolerance
How do you choose the best treatment for your symptoms if you aren’t sure what’s causing them?
What is allergy testing?Allergy testing may help you to find out which triggers might be causing your symptoms and to rule out others. Having the right information can help you to better manage your allergy.
An allergy test can show an indication of your triggers. It is not a diagnosis. Only a doctor can give you a diagnosis of allergy. Any allergy test has to be interpreted alongside your unique medical background and your symptoms.
Is allergy testing worthwhile?We believe allergy testing can make a difference. We want to give you the information you need about allergy testing so you can make the right decision for you.
Once you have the results from your allergy test, you’ll have a better idea of what you could be allergic to. And then tackling your allergy symptoms becomes simpler.
The results from your allergy test can help determine exactly what triggers your symptoms. Which then means you’re set up to take measures to avoid those substances. And most importantly you’ll be able to get the most suitable treatment for your allergy.
How do I get an allergy test?There are different ways to start the journey towards a diagnosis of allergy. You may start right here by reading relevant information online and deciding if allergy testing is right for you. You may wish to start with a home allergy test to get an indication. Or you may prefer to talk directly to your GP for advice. You can choose your own path but consulting your doctor about the results of any allergy test is essential in order to get a diagnosis and access to the best treatment options.
What’s involved with an allergy test appointment?The information we’re giving you in this section is to give you an idea of what you might be able to expect at your allergy test appointment. If you have any questions or concerns about any of the steps or procedures we’re outlining here, do have a chat with your doctor before the test.
Your doctor is likely to ask you questions about your symptoms. Questions such as how badly they affect you, when they occur and how long they last. Keeping a regular log of your symptoms can be useful for talking them through with your doctor.
Since allergy tends to run in families, you might be asked if anyone in your family has ever had hay fever (allergic rhinitis), asthma or eczema.
Your doctor may want to perform a simple examination, such as looking at your eyes, ears, nose and throat. If your symptoms affect your chest, like coughing or wheezing (that whistling sound made when breathing in) and your doctor is concerned about asthma, you might be asked to do a lung function test.
If your allergy symptoms are mild and the cause is obvious, your doctor will be able to offer advice and discuss treatment options with you. But if your allergy is more severe or it’s not clear what’s causing your symptoms, you may be referred for allergy testing. Allergy testing usually takes place at a specialist allergy clinic.
Testing allergy with skin prick tests, blood tests or home allergy testsAllergy tests detect Immunoglobulin E (IgE) in your body.
IgE is an antibody produced by the immune system to protect us from outside intruders such as parasites. In an allergic reaction to substances such as pollen, house dust mites or insect stings, the same defence mechanisms are triggered. Your body produces IgE antibodies specific to the substance it’s reacting to. These antibodies tell cells in your body to release certain chemicals. And it is those chemicals that cause allergy symptoms.
When your body produces IgE antibodies against a specific allergen, then you’re sensitised. To understand how allergy tests work, it’s important to note that there is a difference between being sensitised and having allergy. Don’t worry, we explain the difference below.
What is sensitisation?Sensitisation is the first step of developing allergy. Allergic reactions do not happen the first time you encounter an allergen. First, your immune system has to meet the allergen. For example, by being stung by a bee. Then your immune system memorises the particular structure of the allergen so that it can produce specific IgE antibodies against it. This process is called sensitisation.
Sensitised but not allergicSome people have developed IgE antibodies for a specific allergen, but when they come into contact with the trigger again, they don’t experience any allergy symptoms. These people are sensitised but not allergic. In other words, their immune system is sensitive to an allergen or allergens, but they don’t experience any symptoms of allergy.
Sensitised and allergicFor other people, when they are re-exposed to the allergen, they experience allergy symptoms. These people are both sensitised and allergic. Their immune system is sensitive to an allergen or allergens, and this causes symptoms of allergy.
So, sensitisation does not always lead to symptoms, but symptoms do not develop without sensitisation.
We aren’t sure why some people stop at sensitisation and others progress to allergy. Our immune systems are highly complex and unique and not all processes and mechanisms are fully understood yet.
You can read more about sensitisation here.
Allergy tests show your sensitisation to specific allergensSkin prick tests, blood tests and home allergy tests give you an indication of your sensitisation to certain allergens. So, you’ll have an idea what you’re sensitised to, but that doesn’t mean that you’re necessarily allergic.
As described above, you can be sensitised, but have no allergy symptoms whatsoever. This is why it’s necessary for a doctor to view any allergy test results in light of your symptom history and your medical background.
Skin prick allergy testsSkin prick tests for allergy are one of the most common ways to get an idea of what you are allergic to. Usually, the skin on the underside of your forearm will be used. A drop of fluid containing a known allergen will be placed on your skin and the skin underneath gently pricked. For most people, skin prick testing isn’t painful, but you may find it a little uncomfortable or itchy.
The skin pricking part of the test lasts about ten minutes. Once this is complete, you will need to wait for 15 to 20 minutes before the results can be analysed. If the skin around the needle prick area becomes itchy, red and develops a small swelling called a weal, then you have tested positive for that particular trigger. After your skin prick tests, your doctor or allergy specialist will be able to discuss your results with you.
Read more detailed information about skin prick testing for allergy
Blood allergy testsYour doctor may offer you a blood test for allergy instead of a skin prick test. Blood tests for allergy are especially useful if you have a skin condition. Or if you take certain medications that could interfere with skin prick test results. Blood allergy tests may also be used if the results from skin prick tests did not give clear results.
With blood allergy tests, you are not directly exposed to allergens. Instead, a sample of your blood is checked in the lab. The lab will check the specific IgE levels in your blood. Results are usually available within a couple of weeks and need to be discussed with your doctor.
Read more detailed information about blood tests for allergy
Home tests for allergyA home allergy test allows you to test yourself, at home. Testing at home is quite simple. If you choose a home allergy test to get an idea what might be causing your symptoms, always discuss your allergy test results with your doctor. This way, you’ll be able to get a proper diagnosis and access to effective allergy management.
There are different kinds of self-tests on the market, testing everything from hair samples to your grip strength. These have no scientific validity. We recommend you choose a specific home IgE test that is comparable to the blood tests for allergy performed at a specialist treatment centre.
Home-to-lab allergy blood testsIf you want a comprehensive view of your allergy you can test hundreds of allergens with a home-to-lab allergy blood test detecting IgE in your blood.
A home-to-lab allergy blood test comes with everything you need to collect a small blood sample from your fingertip and instructions on how to do it. With these types of tests, you have to send your blood sample to the lab for analysis. When your sample has been analysed you can usually access your test results online. Your test results will give you an overview of the allergens that you are sensitised to.
Home allergy blood test kitsIf you are curious to discover if you are sensitised to a few of the major allergens such as house dust mites, grass pollen or cat dander you can try a DIY home test kit testing for IgE.
A home allergy test kit involves you taking a small blood sample from your fingertip and performing the simple test yourself. Instructions and everything you need will be included in the kit. If the test has been performed according to the instructions, you will be able to see the results shortly after.
Home allergy test resultsA home allergy test shows sensitisation and can be a first step to finding out if you have an allergy. It doesn’t diagnose allergy. Remember, any allergy test has to be interpreted by a doctor alongside your unique medical background and your symptoms.
Like all allergy tests, there is a possibility that a home allergy test will provide false positive results (meaning the test detects a response to an allergen even though there is none) or false negative results (meaning the test does not pick up on a reaction to an allergen). Do not take any decisions or actions to change your medication or diet based on the results of a home allergy test without consulting your doctor first. Only a doctor can give you a diagnosis of allergy.
Read more detailed information about home allergy tests
What to do following an allergy testOnce you’ve got an allergy diagnosis based on an allergy test and your medical history, you’ll know more precisely what your triggers are. Knowing what you are allergic to means you’re better equipped to manage your allergy symptoms.
As an example, if you’re allergic to pollen, you can check the specific pollen count and plan your day accordingly. You’ll also be able to identify which part of the pollen season is likely to be worst for you, so you can take steps to manage your allergy before the season begins.
Some allergic reactions may also become more understandable to you once you know what you are allergic to. For example, if you’re allergic to birch tree pollen, you may experience a cross-reaction to certain foods like apples and celery?
Or if you’re allergic to moulds or house dust mites, you can focus on controlling the humidity and taking measures to reduce mould or mite levels in your home.
Similarly, if you’re allergic to pet dander there are precautions you can take to minimise this substance in the air you breathe.
And most importantly, you’ll be able to discuss your treatment options with your doctor or allergy specialist and make decisions that are right for you.
klarify - We’re here for youWe have a wealth of further information available for you in the Allergy Know-how area of our website. Find everything you need to know about allergies in our easy-to-read, research-based articles.
Discover tips and practical solutions to help reduce the impact of allergies on your life. We make life with allergy surprisingly simple.
Thank youIf you’ve read all the way to the end of this article, thank you. And we’d love to know what you think. Are you considering being tested for allergy? Have you already had an allergy test done? Has knowing what you’re allergic to made a difference for you? Head over to our Facebook page or email us and share your story.
1399CCa October 2019
