Reasons, Preparation & Procedure To Conduct Allergen Specific Immunoglobulin E Test

Submitted on March 27, 2012

An allergic reaction is the result of hypersensitivity to certain substances like molds, dust mites, pollen, certain foods and beverages, plants and animals. The substance responsible for the reaction is called the allergen. The immune system instantly reacts in an extremely hyperactive manner to an allergen that would normally be absolutely harmless to other individuals, resulting in rash, coughing, sneezing, wheezing, congestion, watery eyes, inflammation, soreness, pain and itchiness among various other symptoms.

Why Allergen Specific Immunoglobulin E is done

In an allergic individual, so as to offer protection to the body with respect to a particular allergen, the immune system produces certain antibodies called immunoglobulin E. The antibodies produced by the body differ with regard to various allergens. This means that the body would not produce similar antibodies for different allergens. Thus, allergen specific immunoglobulin E is a blood test conducted to ascertain specific allergens responsible for allergic reactions based on antibodies present in the blood. Allergen specific immunoglobulin E helps in the prevention of future reactions caused by the allergen. This test may also be done to check the effectiveness of treatment or to ascertain if a person has conquered the allergen. It is usually performed on children so as to help prevent allergic reactions from an early stage in life.


Allergen specific immunoglobulin E does not need any preparation as such. If a child is going for the test, preparing him mentally for the procedure of a technician drawing blood from his arm is recommended so as to avoid tantrums and trauma. Short-sleeved clothing is recommended so as to make the drawing of blood from the arm easier.


First, the technician will prepare the area from where blood is to be drawn by cleansing it with a ball of cotton dipped in spirit or an antiseptic solution. For most blood tests, blood is drawn gradually from a prominent vein located in the inner part of the elbow joint. An elastic band is fastened just above the joint so as to cause the vein to swell up and facilitate the smooth flow of blood. In the case of infants, the heel may be punctured for the same. Once the required amount of blood is drawn, the needle is gently withdrawn, the band is removed and pressure is applied on the puncture wound with a ball of cotton or a bandage to prevent the excess flow of blood. This entire procedure takes only a few minutes. The blood sample is then processed and the results are received in a few days