A food allergy is when your body’s immune system reacts to a food protein because it has mistaken that food protein as a threat.

The food you are allergic to is called a food allergen. The response your body has to the food is called an allergic reaction.

People can be allergic to any food, but eight foods cause the majority of food allergy reactions: milk, eggs, peanuts, tree nuts (such as walnuts or pecans), wheat, soy, fish, and shellfish (such as lobster, shrimp or crab).

Unlike a food intolerance, food allergies involve the immune system and can be life-threatening. With a food allergy, your immune system makes too much of an antibody called immunoglobulin E (IgE). IgE antibodies fight the threatening food allergens by releasing histamine and other chemicals. This chemical release causes the symptoms of an allergic reaction.

Conversely, a food intolerance is when your body has trouble digesting a food. It can make you feel unwell, usually with an upset stomach or gassiness, but it is not life-threatening. The most common intolerance is to lactose, which is a natural sugar found in milk.

Allergic reactions can range from mild to very serious. The most dangerous reaction is called anaphylaxis (pronounced an-uh-fil-LAX-is). Anaphylaxis is a severe allergic reaction that happens quickly and could be fatal.

Anaphylaxis can affect several areas of the body. It can make it hard to breathe and make it hard for your body to circulate blood. The first-line treatment for anaphylaxis is a medicine called epinephrine.

Carefully avoiding problem foods is the only way to prevent allergic reactions. Not all reactions are the same - you can still have a life-threatening reaction to your problem food, even if you have never had a serious reaction before. Past reactions do not predict future reactions.
 
For more information, please visit this website www.foodallergy.org