Immunoglobulins or antibodies, play an important role in the immune system and help fight against harmful bacteria and viruses in the body. There are five classes of antibodies and several subclasses. In those that have an allergy, their immune system overreacts to a harmless allergen (such as food, grass or animal dander) by producing IgE. This reaction usually causes irritation to the nose, lungs, throat and skin.
The allergen-specific IgE antibody test is used to check for an allergy to a specific allergen. It measures the amount of IgE antibody in the blood targeted for a suspected allergen.
What might a high result mean?
Elevated IgE results often indicate an allergy. However, not everyone with an elevated result will have a physical allergic reaction when exposed to that substance – the patient in this case is said to be 'sensitised' rather than allergic to the substance.
The level of IgE does not necessarily predict the severity of a reaction, although the higher the level the more likely you are to have a reaction to the allergen.