Food allergies are an adverse immune response to food protein. Some protein fragments are resistant to digestion and when they are not broken down by the digestive process they are tagged by IgE. This causes the immune system to identify the protein as harmful. The immune system considers the body under attack and an allergic reaction is triggered.
Food allergy reaction can be mild or severe. They can include dermatitis, gastrointestinal distress, and respiratory distress, which can be life threatening in severe cases. Anaphylaxic responses such as biphasic anaphylaxis and vasodilation are severe allergic reactions that require immediate intervention.
Food allergies are typically treated with avoidance and some medications that are designed to minimize the protein allergy reaction. Immunotheraphy involving desensitization is also a method used. The allergy sufferer is exposed to the protein in small increasing doses with the ultimate goal of the immune system becoming desensitized to the protein. Those with extreme food allergies often carry injectable epinephrine in the form of an EpiPen or other delivery device. These emergency devices are used to counteract severe reactions after accidental exposure.