Procedure And Risks Of Intradermal Allergy Test

Submitted on March 27, 2012

What Is an Allergy?

An allergy is an immune system response which is caused by a disorder in the system. The immune system responds to an external stimulus and causes an inflammation in the area that is affected. This is a response to an otherwise harmless substance like a type of nut or pollen. An allergic reaction can be extremely dangerous if it affects the breathing tract or causes an extreme rise in the heart rate.

Thus, Allergy Tests are important to make sure you know what you are allergic to in a controlled atmosphere. This helps you to make the necessary lifestyle changes to avoid being exposed to the allergen. You could also be prepared for the reaction your body will have and have the necessary medication or precautions in place.

Procedure For Intradermal Allergy Testing

The most popular method of testing for an allergic reaction is intradermal allergy testing. This is preferred over other methods as it is cheap, easy to perform, and most significantly, can be performed with great accuracy. The exact allergen can be injected into the skin to check for any reaction to it. Blood based testing may be less accurate and more dangerous.

During intradermal testing, your doctor will inject the allergen under the skin, usually on the forearm or back and mark the area with a pen or marker. You may be required to wait a few minutes, a few hours or even days for a reaction to take place on the skin. Once the period has passed, your doctor will check the area to see if it has developed an allergic reaction or not. An allergic reaction will be represented by a reddish skin appearance and the skin being raised in a bump. The severity of your allergy is proportional to the size and ferocity of your rash. It is possible that no reaction takes place which means that you are either not allergic, slightly allergic or that the allergen has not been injected in the correct place or quantity. A follow up test is always recommended when the reaction is negative.


It should be noted that an allergy test under the skin could trigger off a large scale reaction if enough of the allergen is absorbed by the blood stream. You will be able to tell that something is wrong if you develop a fever, large scale body rash, and other allergic reactions.  Your doctor may prescribe some anti-histamine medication for you to use in case of a full blown reaction. This medication should not otherwise be used as it will negate the results.