Skin testing for allergies is performed to understand the reason behind the occurrence of an allergy. The information helps the doctors to make an allergy treatment plan including when to take anti-allergy medicines, allergy shots (immunotherapy) and allergen avoidance. Allergy skin tests are widely used for diagnosing several types of allergic conditions, such as – Allergic asthma, food allergies, Dermatitis, Latex Allergy, Penicillin allergy, etc. These examinations are safe both for children and adults.
When are these tests ordered?
Skin tests are ordered if you –
Have suffered through severe allergic reaction. This makes you sensitive to certain type of substances that even taking them in small amounts could trigger severe allergic reactions.
Take medications that can interfere your results. This includes taking antihistamines, antidepressants and heartburn medications.
Have certain types of skin conditions like Eczema or Psoriasis, Dermatographism, etc. these conditions can trigger allergies now and then.
What are the types of skin testing methods for allergies?
Several types of skin tests are performed to determine the type of disease you are suffering through. Some of them include Skin test for TB, cancer, food allergies, etc.
Apart from skin tests, blood test like in vitro immunoglobulin E antibody is also used to determine the underlying health condition. However, doctors generally do not recommend blood tests as they can be less sensitive and are more expensive.
What are the risk factors involved in skin tests?
Skin testing for allergies can cause slightly swollen and itchy bumps. In care cases, allergy tests may produce severe, immediate allergic reactions. Therefore, it's highly recommended to perform tests at a good pathology lab where an appropriate emergency equipment and medications are available.
What happens during a skin test?
No matter what type of skin test you have opted for, you will have to go through the three major steps –
- Scratch – It is also known as puncture or prick test. In this, the doctor marks some areas on the forearm and clean them with alcohol. Then a drop of potential allergen in placed on the labelled spots. The doctor then scratches the outer layer of the skin and let the allergen to get in.
- Intradermal – In this, the doctor injects a small amount of allergen into the skin. The site is then examined for 15 minutes for signs of allergic reactions.
- Patch – It is performed to examine whether a particular substance is causing an allergic reaction or not. During this test, the skin is exposed to 20 -30 different allergic substances that can cause dermatitis.
What do the results mean?
A positive test indicates that you may be allergic to a particular substance. You should also keep in mind that in some cases, skin tests are not always accurate. Therefore, it is highly prescribed to consult the doctor regarding the results, diagnosis process or treatment options.
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