In the U.S, around 32 million (1) people have allergies. Twenty-six million of them are adults, and 5.6 million of them are children (2).
Allergy testing helps determine whether your immune system reacts to allergens. If you have an allergic reaction, that means you have an allergy. Most people go for allergy tests as they have had allergy symptoms bothering them.
Also, people with anaphylaxis need to take an allergy test because going to an anaphylactic shock can be potentially life-threatening. Taking an allergy test also requires your health history to determine the cause of severe reactions better.
How do I know if I need an allergy test?
If you are allergic to components in the air like pollen, pet hair, or dust, you may develop hay fever. Hay fever
- Itchy, watery eyes
- Sore throat
- Sneezing, nasal congestion, or running nose
- Shortness of breath
- Wheezing or chronic cough
Food allergy symptoms appear within 30 to 1 hour of food ingestion.
The symptoms may include;
- On the skin: Hives, swelling on face, lips, or tongue, general itching
- Respiratory: Coughing, wheezing, shortness of breath, cheats, or tightness of breath.
- Gastrointestinal: Vomiting, nausea, abdominal pain, cramps, diarrhea
- Cardiovascular: Pale skin, weak pulse, dizziness, or lightheadedness
People allergic to fragrances, latex, or metals develop allergic reactions on the skin like;
- Hives and swelling
- Blisters or a burning feeling on the skin
- Skin rash or itchy skin
What are the types of allergy tests done in the U.S?
There are various types of allergy tests (3) mainly conducted in the U.S to help determine what allergens your immune system is reacting to. Most of the tests below have to be done by your doctor, but only a blood test can be done at home, and you will send the sample to the lab for further analysis.
Skin prick test
To perform this test, your doctor will prick the skin in your forearm or the back with potential allergens. Alternatively, they can place droplets of those allergens on skin and scratch skin to slightly puncture it and allow the allergens to enter your skin surface.
To test for food allergies, your doctor will place the needle in the food being tested and use it to prick your skin to check for allergies. The reaction you will get within 15 minutes will show your doctor whether you’re allergic or not. If you are allergic, your skin will form a minor bump or become red on the marked site.
How to prepare for skin testing
- Ensure that you avoid all antihistamines and sleep aids that may contain antihistamines for five days before the test. The issue with antihistamines is that they will block out positive skin prick test results making the results unreliable.
You can get this test done if the skin prick test is inconclusive. It involves injecting small amounts of allergens into your epidermis. This test checks for allergies to an insect sting, airborne irritants, and medications.
An intradermal test can also help determine weaker allergic reactions. This injection isn’t pleasant and can cause stronger allergic reactions. The results of this test are available within 15 minutes.
This test is mainly for allergies where symptoms become apparent one and a half to three days after contact allergies. Triggers involve;
- Gloves or condoms
If you have a contact allergy, your skin will most likely react the same way it does when inflamed with contact dermatitis. The skin swells up, turns red, and starts itching. Small blisters may form too.
The test involves placing drops of allergen on the skin of your arm and covering the area with a bandage. You can leave with the dressing and go back to your doctor’s office within 48-96 hours. You will have the results read within 2 to 5 days after patch removal by your doctor. Sometimes your doctor can read it ten days after removal. Avoid contact with moisture when you have the patch unless your doctor places a waterproof cover over the patches.
Blood (IgE) test
Sometimes these skin tests can cause severe reactions, and a blood test is preferred. Also, sometimes a skin disease may influence the results of your skin prick test. This test is the most common and simplest one. You can even do it at the comfort of your home by ordering the test kit online. After you have the test kit, you will have to take out your blood sample as instructed; then, you will send your sample back to the lab with your medical history.
The doctor will add allergens to the blood sample and test the IgE antibodies. After getting your results, you can then talk to your doctor about the way forward. Blood tests are also great for investigating other disorders in the immune system like hives, swelling episodes, and primary immunodeficiency disorders. Things that may influence a blood test include; smoking or a parasite infection.
This test occurs in a doctor’s office as it is a bit risky. During this test, you will have to swallow small amounts of allergens as the doctor observes and is ready to help if you develop anaphylaxis.
Considering the population of people in the U.S suffering from allergies, allergy testing is widespread. Once you experience the symptoms of an allergic reaction, you should get yourself an allergy test to help you determine what exactly your body is reacting to. Also, if you aren’t sure whether you have an allergy or intolerance, you can take a test that will help you determine which one it is and the allergens that might be causing it. An allergy and intolerance (4) are pretty different due to the severity. Allergies are severe and can be life-threatening.