Allergic reaction | IgE | Specific IgE | Importance of measure the IgE level | Mast cell | Histamine
For most people, allergy begins as a harmless condition and it may be years before symptoms develop. For others, food, drug or an insect bite can result in sudden, life-threatening anaphylactic shock.
Watch the film explaining allergy
How is an allergic reaction triggered?
An allergic reaction is triggered by the particular substance (allergen) that you are allergic to. When exposed to this allergen, your body senses a foreign invader.
The allergen binds to the IgE antibodies. When this happens, the mast cell breaks open to release inflammatory substances, e.g. histamine, which quickly travels through your body to fight off what it senses as harmful. The histamine affects the body tissue and causes an inflammation.
The symptoms you develop will depend on where in the body the histamine is released. Your runny nose, itchy, watery eyes, shortness of breath and dry skin may all be sings of mast cells reacting in respective parts of your body.
What is IgE and why do you have it?
IgE - Imunoglobulin E - is a type of protein called an antibody. It plays an important role in allergy reactions and is therefore often called the “allergy antibody”.
If you are allergic to a particular substance (allergen), the immune system mistakenly believes that this normally harmless substance, e.g. pollen, is in fact harmful to the body.
When you are exposed to this particular substance, the immune system starts the production of IgE as an attempt to protect you. The IgE antibodies remain in your body and next time contact is made with the allergenic substance, an allergic reaction may occur.
As a result, a person who has an allergy has increased blood levels of IgE.
What is Specific IgE?
IgE is specific to each allergen. That means that IgE to cat can only trigger an allergic reaction to cat.
Why is it important to measure the level of IgE?
A blood test will help identify the amount of IgE in the body. Knowing your IgE levels for different substances will help identify the specific allergic triggers that may be contributing to your symptoms, i.e. if you are allergic and what you are allergic to.
Having a quantitative IgE test result will increase the possibility of ranking how different substances will affect your symptoms. A general rule of thumb is that the higher the IgE antibody value, the greater the likelihood of symptoms appearing. Allergens found at low levels that today do not result in symptoms can nevertheless help predict future symptom development.
What is a mast cell?
Mast cells are an important part of the immune system and can be found throughout the body.
Inside the mast cells are different chemicals, for example histamine, that cause inflammation.
What is histamine?
Allergy symptoms are caused by histamine that initiate an inflammatory response to protect the body. Histamine expands the blood vessels so that the mucous membrane will swell. It is released from the mast cells.