Food allergy or food intolerances affect nearly everyone at some point. People often have an unpleasant reaction to something they ate and wonder if they have a food allergy. One out of three people either say that they have a food allergy or that they modify the family diet because a family member is suspected of having a food allergy.
This difference between the clinically proven prevalence of food allergy and the public perception of the problem is in part due to reactions called “food intolerances” rather than food allergies. A food allergy, or hypersensitivity, is an abnormal response to a food that is triggered by the immune system. The immune system is not responsible for the symptoms of a food intolerance, even though these symptoms can resemble those of a food allergy. But only about three percent of children have clinically proven allergic reactions to foods. In adults, the prevalence of food allergy drops to about one percent of the total population.
It is extremely important for people who have true food allergies to identify them and prevent allergic reactions to food because these reactions can cause devastating illness and, in some cases, be fatal.
How Allergic Reactions Work
An allergic reaction involves two features of the human immune response. One is the production of immunoglobulin E (IgE), a type of protein called an antibody that circulates through the blood. The ability of a given individual to form IgE against something as benign as food is an inherited predisposition. Generally, such people come from families in which allergies are common—not necessarily food allergies but perhaps hay fever, asthma, or hives. Someone with two allergic parents is more likely to develop food allergies than someone with one allergic parent.
The complex process of digestion affects the timing and the location of a reaction. If people are allergic to a particular food, for example, they may first experience itching in the mouth as they start to eat the food. After the food is digested in the stomach, abdominal symptoms such as vomiting, diarrhea, or pain may start. When the food allergens enter and travel through the bloodstream, they can cause a drop in blood pressure. As the allergens reach the skin, they can induce hives or eczema, or when they reach the lungs, they may cause asthma. All of this takes place within a few minutes to an hour.
Culled From: Foodreference.com
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