Blog Banner
Allergy Testing: Take Care of Your Health Condition
11 Oct 2023

Allergy Testing: Take Care of Your Health Condition

Allergy testing is an examination performed by the allergy specialist to know if your body has allergic reaction to any known substance. You need to conduct the examination with skin prick or blood test. The immune system of your body is said to be natural defense and allergies may happen when the immune system seems to overreact to something in the environment. For example, pollen may cause your immune system to overreact which can be the reason for:

  • blocked sinuses
  • runny nose
  • sneezing
  • watery or itchy eyes
  • coughing or wheezing

Different kinds of allergens

Allergens are certain substances which may lead to allergic reaction. Three kinds of allergens include:

  • Inhaled allergens: This may affect the body after coming into contact with the membranes of the nostrils, throat or the lungs. Pollen is said to be the most common form of inhaled allergen.
  • Ingested allergens: These are present in certain types of foods such as – peanuts, seafood and soy.
  • Contact allergens: This gets in contact with the skin and gives some kind of reaction. An example can be rashes and itching which occurs from poison ivy.

Allergy tests will expose you to small amount of specific allergens for recording the reaction.

What are the types of allergy tests?

Different tests are there to find out whether you are having allergies. Talk to your healthcare provider and find out the right method as per your symptoms and suspected allergens.

  • Skin tests – Skin tests can be used to detect several potential allergens. This consists of –food-related, contact and airborne allergens. Three skin tests include – intradermal, scratch and patch tests.
    The doctor will try a scratch test at first and an allergen is put in a liquid. After this, the liquid is placed on the skin part with special tool that punctures allergen lightly into the surface of skin.
    You need to be monitored closely and see how your skin reacts to your foreign substance. If there is swelling, redness or skin itchiness over the test site, then you will be allergic to that specific allergen.
    When the scratch test is uncertain, the doctor may ask to conduct intradermal skin test. This test requires injecting small amount of allergen into your skin’s dermis layer. The doctor will then monitor your skin reaction.
    Another kind of skin test is the patch test. This consists of using adhesive patches loaded with suspected allergens and then placing patches on your skin. Patch testing can be done to evaluate for allergic contact dermatitis cases.
    The patches remain on the body after leaving your doctor’s clinic. These patches will be assessed after 48 hours of the application and again at 72 to 96 hours after the application.
  • Blood tests – You might suffer from severe allergic reaction after performing skin test or cannot undergo it. In such case, the doctor may ask to conduct a blood test where your blood sample is being taken and then sent to the laboratory. This will detect the presence of antibodies that fight against specific allergens. Also known as ImmunoCAP, this test can identify the presence of IgE antibodies to specific allergens.
  • Intradermal skin test – You may perform intradermal skin test when skin prick test results seem to be negative. The provider injects small amounts of allergen into your skin’s outer layer or epidermis. This test will check for allergies to airborne irritants, insect stings and medications.
  • Patch test – This test will determine the exact cause why you are suffering from contact dermatitis. The provider puts allergen drops onto your arm skin and covers the area by using a bandage. Your provider can put a bandage where there is allergen. You need to leave bandage on and then return to your provider’s office within the next 48 hours. Then the provider removes bandage for checking any kind of rashes or other reactions to your skin.
  • Challenge tests – You need to conduct this test under the supervision of a provider. People who suffer from suspected food or drug allergies can ingest small amount of allergen. An allergist performs this test and when you suffer from anaphylaxis, he gives an epinephrine injection to prevent the reaction.

How you can prepare for allergy testing

Before undergoing an allergy test, the doctor will ask you about your past family record, change in lifestyle and more. They will probably tell not to take following medications before the allergy test as they can affect test results:

  • certain heartburn therapy medications like famotidine
  • benzodiazepines such as lorazepam or diazepam
  • prescription and over-the-counter antihistamines
  • systemic corticosteroids when performing patch test
  • tricyclic antidepressants like amitriptyline

Why you need to conduct allergy skin tests

Allergy skin tests may help diagnose allergic conditions which include the following:

  • Allergic asthma
  • Bee venom allergy
  • Dermatitis or eczema
  • Food allergies
  • Hay fever or allergic rhinitis
  • Penicillin allergy

Skin tests are a safe choice for children and adults of all ages, including infants. The doctor may suggest conducting skin tests when you:

  • Have certain skin conditions – If psoriasis or eczema affects large skin areas on your arms and back, then there may not be clear as uninvolved skin means conducting a test. Some skin conditions like dermatographism may lead to unreliable test results.
  • Have had allergic reactions in the past – Your skin might be sensitive to a few substances that could trigger anaphylaxis or life-threatening reaction.
  • Take medications interfering with test results – Some of these include antihistamines, antidepressants and heartburn medications. The doctor may ask to continue taking these medications than discontinue them for the time being before your skin test.

How do you know if you need to get tested for allergy?

You should visit an allergist if:

  • Your allergies lead to various symptoms such as – nasal congestion, chronic sinus infections, or difficulty breathing.
  • You suffer from hay fever or other allergy symptoms for several months throughout the year.

What can the results of allergy test mean?

The results for allergy test may mean:

  • Positive: You seem to be allergic to a specific substance. Even when the test results correctly denote you are having an allergy, it does not mean you will react to that allergen all the time. On the other hand, a false positive test result is possible from a blood (IgE) test. A false positive means the results denote you are suffering from an allergy when you actually do not.
  • Negative: You are not allergic to that substance. It is unusual to get a false negative allergy test result which means you do not have an allergy when you actually do have.

What happens when you suffer from allergy?

Based on the allergy, the healthcare provider may suggest one or more of these steps:

  • Lessen the exposure to allergens: Avoid the ones that may be the reason for severe reactions such as certain food items or latex.
  • Take allergy medications daily: Antihistamines may help to lessen or prevent allergic rhinitis as well as other symptoms.
  • Get allergy shots: This kind of immunotherapy can lessen the immune system’s response to some allergens such as pet dander. You may take allergy shots for three to five years for getting maximum benefit. Allergy shots are expensive but they offer long-lasting relief even after shot series has been completed.
  • Carry your medical alert card: A medical alert card will let others know about your severe allergy. It will inform that you can have anaphylactic response to bee stings, peanuts or other types of allergens.
  • Take epinephrine injection: You need to bring this medicine with you in the case you are at risk for getting anaphylactic allergic reaction.

Do allergy testing causes you pain?

Allergy skin tests are not painful. This kind of testing uses needles which penetrate into the surface of your skin. You will not bleed or feel more than mild discomfort.

Allergic reactions may range from irritating congestion to life-threatening shock. With the help of allergy tests, you can detect substances that lead to such allergic reactions. The healthcare provider at the private walk in clinic will select the right test for you based on your symptoms and possible allergy triggers. If you are suffering from allergies, then you need to take steps for getting relief.


Suite 2, 117a Harley Street, London W1G 6AT


020 70968853

Opening HoursOpening Hours

Mon - Fri 9:00 - 18:00

Sat - Sun 10:00 - 14:00