3 Reasons Why Would You Need an Allergy Test
1. Unexplained allergic reactions
It can sometimes be hard to know what substance is responsible for an allergic reaction, but not knowing what you're allergic to can be deadly. If you have an unexplained allergic reaction, your doctor might recommend allergy testing to determine the cause.
2. Seasonal allergies
Choosing a treatment for seasonal allergies can be a challenge. Your doctor may suggest allergy testing to better understand what pollens, grasses, and weeds you're allergic to. This type of testing can help you learn more about what substances you should avoid.
Pollen counts fluctuate throughout the year, but allergy testing can help you predict when your allergies might worsen. Knowing when to expect more severe symptoms can help you manage your allergies.
3. Genetic risk of allergic reactions
Allergies can sometimes be inherited. Your doctor may recommend allergy testing if a family member experiences a life-threatening allergic reaction. Medical tests can help determine if you share the same allergy.
Understanding Allergy Tests
There are two main types of allergy tests: blood tests and skin prick test.
During a blood test, a technician uses a sterile needle to collect a blood sample. This sample is then sent to a lab, where it's tested for specific antibodies. These antibodies can determine what substances you're allergic to.
Blood tests are especially helpful for detecting food or medication allergies. They're often used for patients who are at risk for severe allergic reactions or can't tolerate a skin prick test.
During a skin prick test, a doctor or nurse lightly scratches the skin's surface. Next, your doctor or nurse applies different allergens to the scratched area. After 15 to 20 minutes, your doctor examines the area and records the results.
If you are allergic to the tested substances, the area will generally turn red or swell up. If there is no reaction, it's unlikely that you're allergic to the tested substance.
Depending on your medical history, your doctor may suggest using one or both of these testing methods. Skin prick tests are often less expensive than blood tests. They are also very efficient, as they allow your doctor to test you for many allergens at once. However, they also involve direct exposure to potential allergens. People who are at risk of a severe allergic reaction may not be eligible for skin prick tests.
Risks of an Allergy Test
Most side effects caused by a skin prick test are mild. After your test, you may develop a rash, itchy welts, or hives. These reactions are often resolved with steroid creams or oral antihistamines, but some patients may experience a life-threatening allergic reaction known as anaphylaxis. Anaphylaxis can cause your airway to swell or trigger symptoms of shock.
Most people are not at risk for anaphylaxis. Before performing a skin prick test, your doctor will ask you about your medical history. If your doctor believes that you may be at risk for anaphylaxis, he or she may recommend blood tests instead. Few health risks are associated with allergy blood tests.
If your doctor decides to perform a skin prick test, he or she will observe you carefully during the test. If a severe reaction occurs, your doctor can give you medication to prevent life-threatening complications.
What to Expect with an Allergy Test
Blood tests take place inside a designated laboratory collection area. A medical specialist known as a phlebotomist performs this type of test. Your phlebotomist inserts a needle into one of the veins in your arm to collect the specimen. This process should take just a few minutes.
Most people feel fine during their blood test, but in rare cases, some people may faint or feel dizzy. Tell your phlebotomist if you experience these symptoms. After the test is over, ask when it's safe to resume your normal activities.
Skin prick tests are performed inside a doctor's office. Before the test begins, your doctor or nurse may ask you to remove your shirt and bra. Next, you lie down on a table while they make marks on your back or arm. These marks help medical staff keep track of the different allergens.
Your doctor or nurse then pricks your skin and applies a separate serum to each skin prick. Each serum contains a specific allergen. During the test, you may feel some itching or irritation, but it's important not to scratch the test area. After 15 to 20 minutes, your doctor or nurse examines the test area. They make a careful list of all the allergens that triggered a reaction.
After your allergy testing is complete, your doctor explains what substances you're allergic to, if any. He or she helps you develop a treatment plan for managing your allergy symptoms. Your doctor can also offer advice on eliminating allergens from your environment.
Questions to Ask Your Doctor About Allergy Tests
- Where will this test be performed?
- What health risks are associated with an allergy test?
- What can I do if I'm feeling itchy or uncomfortable after my test?
- Who will interpret my result?
- How will I receive my results?
- What allergy treatments are available?
Allergy Testing May Also Be Known as:
- Allergy skin test
- Skin prick test
- Puncture test
- Scratch test
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- Healthline. Allergy testing. https://www.healthline.com/health/allergy-testing#purpose
- KidsHealth. All about allergies. https://kidshealth.org/en/parents/allergy.html
- WebMD. Blood testing for allergies. https://www.webmd.com/allergies/blood-test#1
- American College of Allergy, Asthma, and Immunology. Allergy testing. https://acaai.org/allergies/allergy-treatment/allergy-testing
- Healthline. Anaphylaxis. https://www.healthline.com/health/anaphylaxis
- Verywell Health. 7 tips for making a blood draw easier. https://www.verywellhealth.com/tips-for-making-a-blood-draw-easier-3156931