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A food allergy occurs when an individual's immune system mistakes a food protein for a foreign substance. The immune cells overreact to substances that are normally harmless. During the allergic reaction, the body releases chemicals that trigger symptoms that can than affect the eyes, nose, and throat, as well as the skin and the lungs. Even a trace amount of the allergen can cause a reaction in sensitive individuals.
Food allergens are the parts of foods (usually proteins) that cause allergic reactions. Most allergens can still cause allergic reactions even after they are cooked or have been digested. However, some allergens (usually from fruit and vegetables) only cause allergic reaction when they are eaten raw. Such reactions are generally limited to the mouth and throat.
Trace amounts of food allergens may also trigger reactions in some patients. For instance, patients who are allergic to peanuts may develop an allergic reaction after eating food that has been manufactured in the same facility as peanuts. Some patients may develop an allergic reaction if a kitchen utensil touched a food allergen and then touched their food. It is also possible to have an allergic reaction after smelling food allergens.
The severity and duration of allergy symptoms vary among patients. Symptoms can develop anywhere from several minutes to several hours after exposure to the food allergen. Anaphylaxis is the most severe type of allergic reaction that may occur. The most serious symptoms of anaphylaxis include low blood pressure, breathing difficulties, shock, and loss of consciousness, all of which can be fatal. About 30,000 Americans need emergency room treatment and 150 die each year because of allergic reactions to food, according to the U.S. Food and Drug Administration (FDA).
Certain food allergies, including allergies to peanuts, tree nuts, and/or shellfish, may have longer-lasting effects. However, new studies show that up to 20% of people who are allergic to these foods may lose their allergic sensitivities over time.
Food allergy is usually prevalent among individuals who have a family history of allergies. About eight percent of children, and two percent of adults in the United States are estimated to have food allergies. Food allergies are most common during the rst few years of life, and allergic sensitivity declines over the last decade of life for most patients.
To help patients avoid known food allergens, the U.S. Congress passed the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA). The law, which went into effect January 1, 2006, requires food manufacturers to clearly state on their