Allergic Reaction

Allergic Dermatitis

Allergic Dermatitis

An allergic reaction is simply the body’s immune system’s response to an unknown allergen (a substance that causes allergies). In oral allergy syndrome the most important allergens are pollens, specifically trees, grasses, and weeds. Before talking about what goes into the basics of an allergic reaction there are some terms you should know:

  1. Allergen. This is the substance that causes allergies. Common allergens are pollens, dust mites, molds, pet dander, medications, and insect stings. In the case of oral allergy syndrome, pollens are the main allergen.
  2. Immune system. This is the system in your body that fights diseases and “invaders” in the body. Your immune system is constantly on alert for things that shouldn’t be floating around in your body. If the immune system thinks there is something in your body that shouldn’t be there it goes into attack mode to get rid of it. The immune system is valuable in fighting infection and diseases but can sometimes get confused and begin attacking things it shouldn’t which is what happens with allergic reactions.
  3. Antibody. This is a type of protein produced by the immune system that attaches to the things in your body that shouldn’t be there, such as bacteria’s, parasites, or allergens. The antibody then simply speaking raises a red flag alerting the immune system that there is something bad in your body to help the immune system begin its attack on the invader. IgE is the antibody that raises the red flag in allergic reactions.
  4. Immunoglobulin E or IgE. A true allergy involves IgE. IgE is called the “allergic” antibody and is part of the immune system that is used to identify and label the “invaders” and allergens in your body and unfortunately also helps cause allergic reactions.

Here’s what happens in a normal allergic reaction:

The trees are blooming and you begin to unintentionally breathe tree pollen. The tree pollen gets into your body and your body says “Hey! You shouldn’t be here!” So the immune system creates and produces an IgE antibody that will help it identify the next time the tree pollen comes into your body. Without you even realizing it, tree pollen once again enters your body and the IgE antibody grabs the allergen, raises its red flag, and yells “It’s back! It’s back!” to the immune system. The IgE then basically takes the allergen to its “leaders,” mast cells and basophils. The IgE and allergen then attach to the mast cells and basophils starting a complex series of reactions to fight off, kill, and rid the body of the allergen. The mast cells and basophils are the “muscle” behind the immune system and are responsible for producing and releasing inflammatory substances, such as histamine, aimed at killing and disposing of the allergen. These inflammatory substances, such as histamine, are one of the major causes of the symptoms of hay fever such as runny nose, itching, and sneezing. 

What happens in oral allergy syndrome?

In oral allergy syndrome for some unknown reason the immune system gets confused with things that look similar. It’s almost like your immune system could use a good pair of glasses or contacts but unfortunately they don’t make those for the immune system (though that would be a great idea!). So, let’s say your allergen is tree pollen and your body has IgE antibody ready and waiting for the next time you come in contact with tree pollen. But you don’t come in contact with tree pollen, instead you eat an apple. For whatever reason the IgE looks at the apple, takes a double-take, and says “You don’t smell like tree pollen, but you look a lot like it…so close enough!,” raises its red flag, and yells “The tree pollen is back!” The IgE does exactly as it normally does and the body reacts in the same way…except to the wrong thing.



Disclaimer: The information contained in this site is for educational purposes only, and should not be used as a substitute for a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition. Click here to read the full disclaimer.
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