Different Types Of Skin Testing For Allergy

Submitted on March 27, 2012

A skin allergy test helps identify the substances that cause any kind of allergy symptoms. Skin allergy testing involves the application of an allergen to your skin, and then observing if there are signs of reaction on the skin. Doctors take into consideration your medical history as well as these skin allergy tests to figure out whether certain symptoms that you exhibit, such as sneezing, skin rashes, and wheezing, are due to some allergies that you may have. A skin allergy test can also help in the identification of the substances that could be the cause of your allergic reactions. With the results from these tests doctors can work out a plan to treat your allergies.

Skin allergy testing can be used in the diagnosis of a number of allergic conditions such as food allergies, bee sting allergy, penicillin allergy, hay fever and many more. Age is not a barrier as far as these tests are concerned and both adults and children can go in for these tests. Your doctor will however advise against skin tests if you are allergic to certain medications that might hamper your test results, if you have some skin disease that is severe, or if you are sensitive to certain allergens.

Types of Allergy Skin Testing

There are three types of skin tests for allergies. The intradermal test, the scratch test, and what is known as the patch test.

  • In a scratch test the skin on your forearm or back is cleaned with alcohol by the doctor. With the help of a pen, the areas of your skin are marked to be able to identify the allergen that is being tested. The allergen extract is placed on a related mark. Your doctor will then make a small prick to allow the extract to enter the skin's epidermis.
  • In an intradermal test the doctor will examine and clean the skin and then inject the allergen under the skin. This is very similar to what is done in a tuberculosis test.
  • In a patch test, as the name suggests, the doctor applies the allergen to a patch and then places this on the skin. By doing this, your doctor is able to zero in and find out if there is contact dermatitis. Your skin will generally get irritated and itch if there are some allergic antibodies present in your system.

Both the scratch test and the intradermal test take about an hour, while the skin patch allergy test would take about 48 hours. This test takes long as the patch has to be worn long enough to determine if there is any kind of delayed reaction.