A food allergy is a condition in which certain foods trigger an abnormal immune response.
Your immune system identifies the proteins in a food as harmful and tries to protect you from these misidentified proteins by releasing chemicals, like histamine.
For people who have a food allergy, even exposure to very small amounts of the problem food can cause an these allergic reactions.
The most common foods to trigger allergic reaction are: tree nuts, eggs, fish, shellfish, milk, soy, peanuts, and wheat and gluten.
Food intolerance is often misread as food allergies. Intolerance never involves the immune system and are not life threatening.