A food allergy is an abnormal physical reaction of the immune system to a particular food. Food allergens are proteins that are not broken down during cooking or by enzymes in the body during digestion. In contrast, a food intolerance is an adverse reaction to a food that does not invoke an immune response, e.g. lactose intolerance.
When a food allergen enters the blood, it can cause a drop in blood pressure; when they are near the skin, hives can develop; when they make their way to the lungs, asthma can occur. The reactions can appear quickly as a few minutes after eating the offender. This may result in an anaphylactic reaction, which are severe, life-threatening reactions that cause constriction of the airways in the lungs which inhibits the ability to breathe.
Eggs, milk and peanuts are the most common sources of food allergies in children. In adults, shellfish, peanuts, tree nuts, fish, wheat, soy and eggs are most common. These foods together cause 90 percent of all reactions to food allergens. Some children will outgrow their reactions to milk and up to 20 percent of them outgrow a peanut allergy. Adults are rarely able to rid themselves of a food allergy once it is established.
Food allergies appear to be increasing. See a previous post HERE. The following article discusses some of the reasons they be on the rise.