Food Allergy Testing: Everything You Need to Know
What is Food Allergy?
Food allergy is an abnormal immune-mediated reaction that is triggered when the body perceives a certain meal as hazardous. Soon after eating an allergy causing food, the body shows symptoms including rashes, stomach ache, cold, etc. these reactions may range from mild to severe. In some people, food allergies can cause life-threatening reactions that may be fatal. On an average, about 3 per cent of adults and about 6 to 8 per cent of children under the age of 3 are affected by an allergy. Most children outgrow a food allergy as they grow old.
A reaction is triggered when immune system identifies a protein as a potential threat to the body and show appearance of symptoms.
Types of Allergens
There are major two categories of food allergies
Food allergy is considered as an increasing disease over time. It is generally accepted that food allergy affects approximately 2.5% of the general population. For some people, an allergic reaction to offended food may be uncomfortable but not severe. But for others, an allergic food reaction can be frightening and sometimes life-threatening. Reactions due to allergies are expected to develop within a few minutes to two hours of exposure to the offended food.
Immunoglobulin E (IgE) mediated: The immune system produces antibodies termed Immunoglobulin E (IgE) antibodies, which cause symptoms. Certain foods react with these IgE antibodies.
Non-IgE mediated: When a certain food is consumed, other components of the immune system react. There is no IgE antibody involved in this reaction, which causes symptoms. Food allergies can be mediated by IgE as well as non-IgE mediated food.
Symptoms of Food Allergy
A food allergy might cause moderate symptoms in one individual and severe ones in another. They can even be life-threatening at times. Food allergies can cause the following symptoms:
- An itchy or tingling sensation in the mouth
- Skin conditions such as hives, itching, or eczema
- Swelling of the lips, face, tongue, or throat
- Stuffy nose, wheezing, or difficulty breathing
- Stomach pain, diarrhoea, or throwing up
- Dizziness or fainting
Causes of Food Allergy
Food allergies include two parts of your immune system. One is immunoglobulin E (IgE) – a type of protein called an antibody that moves through the blood. The other is mast cells, which you have in all body tissues but specifically in places like your nose, throat, lungs, skin, and digestive tract.
When you eat a certain type of food for the first time, certain cells make a lot of IgE for the part of the food that triggers your allergy, called an allergen. The IgE gets released and attaches itself to the surface of mast cells. You won’t have a reaction just yet, but are set up for one. When u consume the same food the next time, the allergen interacts with that IgE and triggers the mast cells to discharge chemicals such as histamine. The reaction is triggered in the particular area where the tissue is located, causing symptoms.
The majority of food allergies in adults are caused by proteins found in:
- Shellfish, such as shrimp, lobster and crab
- Peanuts
- Tree nuts, such as walnuts and pecans
- Fish
Food allergies in children are frequently triggered by proteins found in:
- Peanuts
- Tree nuts
- Eggs
- Cow’s milk
- Wheat
- Soy
What Is Food Allergy Testing?
Food allergy testing is performed to determine whether you or your child has a food allergy. It can also be used to determine whether you have a real allergy or a food sensitivity. Food sensitivity, also known as food intolerance, is a condition in which the body reacts to certain foods.
Food Allergy Test: Diagnosis and Treatment
To pinpoint the allergy problem — and determine the treatment – your doctor will ask questions about your symptoms and habits. You’ll also need various tests.
- Finding the Cause of Allergies: An allergist may be able to help identify your allergy triggers. Several different types of allergy tests are uses to do this.
- Questions Your Doctor Will Ask You: To evaluate if your problem is allergy-related, your doctor will most likely ask you a number of questions. Here’s what to anticipate.
- Allergy Skin Test: One way for your doctor to figure out what’s causing your allergy symptoms is to do a skin test.
- Allergy Blood Tests: Allergy blood tests detect and evaluate the number of allergen-specific antibodies in your bloodstream. Your body produces antibodies against allergy triggers when you come into contact with them.
- Food Allergy Testing: The most contentious component of food allergy treatment is testing. New recommendations, on the other hand, assist clinicians in making the greatest use of food allergy tests.
- Diary of Allergy Symptom: If you have a food allergy, you may require to keep a food diary and eliminate certain foods from your diet in order to determine what you’re allergic to.
- Elimination Diet: The elimination diet is eliminating particular foods or substances from your diet that you and your doctor believe are causing your allergy symptoms (common allergy-causing foods include milk, eggs, nuts, wheat, and soy). Over a few weeks, your doctor will monitor your progress on this diet.
Food Allergy Test Results Interpretation
The results of the blood test will disclose what you are allergic to. You can test positive for something even if you’ve never experienced an adverse reaction to it. A negative test indicates that you are unlikely to have a real allergy. That means your immune system isn’t likely to react to the allergen.
Types Of Food Allergy Test
The testing may begin with your allergist performing a physical exam and asking about your symptoms. After that, he or she will perform one or more of the following tests:
- Oral challenge test: Your allergist will give you or your kid small amounts of the food considered to be the source of the allergy during this test. The food can come in the form of a capsule or an injection. If you have an allergic reaction, you will be closely monitored. If you have an allergic response, your allergist will treat you right away.
- Elimination diet: The elimination diet is used to determine which specific item or foods are the sources of the allergy. To begin, remove all questionable foods from your child’s or your diet. After that, you’ll gradually reintroduce the items to your diet, monitoring for allergic reactions. An elimination diet will not reveal whether you have a food allergy or a food sensitivity. For anyone at risk of a severe allergic reaction, an exclusion diet is not recommended.
- Skin prick test: Your allergist or other healthcare providers will apply a little amount of the suspected food to the skin of your forearm or back during this test. After that, he or she will pierce the skin with a needle to allow a small bit of food to penetrate beneath the skin. If a red, itchy bump appears at the injection site, you are most likely allergic to the food.
- Blood test: This test analyses the blood for antibodies called IgE. When you are exposed to an allergy-causing chemical, your immune system produces IgE antibodies. A health care expert will collect a blood sample from a vein in your arm using a tiny needle during a blood test. A small amount of blood will be collected into a test tube or vial once the needle is inserted. When the needle goes in or out, it may sting a little. It normally takes less than five minutes to complete this procedure.
How Allergy Testing Is Performed
To identify a food allergy, doctors frequently employ a combination of skin testing and blood tests. The most common and quickest food allergy test is skin testing. Your doctor can test you for multiple foods at the same time.
- A scratch test is a common skin test. A doctor or nurse will scrape the skin with a small amount of liquid extract of an allergen for this test (such as pollen or food). Allergists typically do skin tests on the forearm or back of a patient. After that, the allergist waits about 15 minutes to check if reddish, raised areas (known as wheals) appear, suggesting an allergy.
- An allergist may use a blood test in addition to skin testing to confirm a food allergy. This entails drawing a small sample of blood and sending it to a laboratory for analysis. The lab looks for IgE antibodies to certain meals in the blood. If a person’s blood contains enough IgE antibodies to a specific food, it’s quite likely that he or she is allergic to it.
Which Food Allergy Test Is Best
The easiest way to find out if you have food sensitivities is to go on an elimination diet and then test each eliminated food one by one after a period of avoidance. MRT, ALCAT, and IgG antibody tests all have limitations, and the accuracy of these tests varies from lab to lab.
Why Allergy Testing Is Performed
Allergy testing is done to find out which pollens, moulds, or other substances you are allergic to. Allergies may necessitate the use of medicines. You could also try to avoid your allergy triggers.
Allergy skin tests are commonly performed to aid in the diagnosis of allergic disorders such as:
- Hay fever (allergic rhinitis)
- Allergic asthma
- Dermatitis (eczema)
- Food allergies
- Penicillin allergy
- Bee venom allergy
How Much Does a Food Allergy Test Cost?
The cost of every test is determined by a number of factors. They include things like the sort of test, the instruments used, the doctor’s experience, and so on. Furthermore, the cost of a food intolerance test varies depending on where you live in the world.
Who Should Do Food Allergy Test?
Food allergy testing may be necessary if you or your kid exhibit specific risk factors and/or symptoms. Food allergies can be caused by several factors, including the following:
- A family history of food allergies
- Other food allergies
- Other types of allergies, such as hay fever or eczema
- Asthma
- Rapid swelling of the tongue, lips, and/or throat
- Tightening of the airways and trouble breathing
- Fast pulse
- Dizziness
- Pale skin
- Feeling faint
How Accurate Is Food Allergy Testing?
The accuracy of food intolerance tests is determined by the type of test and the location where it is performed. It also depends on the doctor’s skills and the lab professionals who put the results together. Furthermore, your test results might be influenced by a variety of factors, and your food sensitivities can change over time.
How To Prepare for Allergy Testing?
There is no need to fast before taking a food sensitivity or intolerance test. You also don’t have to make any dietary changes before the test. The food intolerance test includes taking blood and exposing it to a variety of foods to see if you are allergic to them. The level of food intolerance is determined by how the body reacts to specific antibodies.
How To Get Tested for Food Intolerances
If you want to be tested for food intolerances or sensitivities, choose a healthcare centre or hospital near you that provides this service. Make sure, however, that the doctors on hand at the centre have prior experience with these testing. So, before you take the test, call ahead and get some advice.
How To Read Food Intolerance Test Results
If your IgG or IgE levels are raised, it does not always mean you have a food intolerance, depending on your test results. By eliminating certain foods from your diet, you can eliminate the chance of digestive disorders or food-related symptoms like gastrointestinal distress, headaches, dry and itchy skin, and exhaustion.
Depending on your tolerance levels, the foods are either labelled red or yellow once you receive the findings. If a food is labelled red, it should be avoided at all costs. If it turns yellow, though, you should cut back or alternate your intake for at least three months. If you have any concerns about the test results, you should consult a doctor.
Allergy Vs. Intolerance Vs. Sensitivity
Food allergies, as you may be aware, can be life-threatening if undetected or mistreated. However, by performing the test and eliminating specific foods from your diet, you can treat food intolerance or sensitivity. To understand the variations between food allergy, food intolerance, and food sensitivity, look at the table below.
Sr. No. |
Condition | Allergy | Intolerance | Sensitivity |
1 |
Immune System | Yes | No | Yes |
2 |
Foods | Milk, egg, peanut, tree nuts, wheat, soy, fish, and crustacean shellfish. | Fermentable carbs, milk (lactose), legumes and certain vegetables, fruits, grains, and sweeteners. | Varies from person to person and could include everyday foods. |
3 |
Onset of symptoms | Rapid | 30 minutes to 48 hours after eating. | Few hours to few days. |
4 |
Symptoms | Trouble swallowing or breathing, nausea, vomiting, hives. Can result in anaphylaxis. | Trouble swallowing or breathing, nausea, vomiting, hives. Can result in anaphylaxis. | Headaches, joint pain, digestive issues, skin issues, and overall feeling of being unwell. |
5 |
Testing Method | Skin prick tests or blood tests of IgE levels to specific foods. | Breath tests could identify fermentable carb intolerances (lactose, fructose). | Many tests available, but their validity is uncertain. |
Food Allergies Testing: FAQS
Q1: Can you test for food allergies?
Yes, you can opt for a food allergy test when you have food intolerances and sensitivities that can cause discomfort, swelling, rashes and GI reactions.
Q2: What kind of doctor does food allergy testing?
Your doctor may recommend you to an allergist or immunologist (doctors who specialise in allergies) for testing if your medical history shows you have an allergy.
Q3: Who can test me for food allergies?
An allergist will most likely prescribe a blood test (such as an ImmunoCAP test) and/or a skin prick food allergy test to see if you have food-specific IgE antibodies in your system.
Q4: Can I test myself for food allergies?
Self-tests are not recommended unless you have Food intolerances and sensitivities.
Q5: Why do I need food allergy testing?
Food intolerance testing is performed to determine if you or your child has a food sensitivity. It can also be used to determine whether you have a true food intolerance or a food sensitivity.
Q6: Will I need to do anything to prepare for the test?
The best thing to do before going in for food allergy testing is to relax. You can also ask your gastroenterologist or nurse practitioner to write you a prescription for numbing cream. You do not need to fast before taking your food intolerance or food sensitivity test. You also need not adjust your diet before your test in any way.
Q7: Are there any risks to the test?
If it is done correctly and interpreted by a board-certified allergist, skin tests or blood tests are reliable and can rule in or out food allergy.
Q8: Does food allergy testing is covered by insurance?
Most insurance companies will not cover the cost of an at-home food sensitivity test. You can go to your primary care physician and get tested.
After Allergy Testing
The most common side effect of skin testing is swollen, red, itchy bumps (wheals). These wheals may be the most noticeable during the test. Swelling, redness, and itching may begin a few hours after the test and linger for a few days in some patients.
Schedule At Home Food Allergy Test in Dubai
As the pandemic reaches its peak, it gets difficult to step out of the house and visit hospitals for tests. However, with Aims Healthcare’s Lab at Home service in Dubai, you can now get a test from the comfort of home. Just make a phone call, and a professional DHA Licensed Nurse and lab technician will reach your door step at the scheduled time, collect the required samples using the most advanced tools, and provide you with accurate findings as per your requirements. To receive personalized medical care exclusively at your doorstep 24×7 and 365 days, get in touch at +971 458 26 555 or fill out the contact form for more information.
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