As many as 25% of American households; alter their diet because of suspected food allergies in at least one family member. Actually, however, only about 4% of adults and 8% of children have clinically proven true allergic reactions to food.
People who have food allergies must identify and prevent them because, although usually mild and not severe, these reactions can cause devastating illness and, in rare instances, can be fatal.
Food allergy is an abnormal response to food that is triggered by a specific reaction in the immune system and expressed by certain, often characteristic, symptoms. All the symptoms of food allergy occur within a few minutes to hours of eating.
Most common symptoms include:
As the allergens travel through the blood vessels, they can cause dizziness, weakness, and anaphylaxis, which is a sudden drop in blood pressure. Anaphylactic reactions can be fatal if not treated quickly.
Other kinds of reactions to foods that are not food allergies include food intolerances (such as lactose or milk intolerance), food poisoning, and toxic reactions. Food intolerance also is an abnormal response to food, and its symptoms can resemble those of food allergy. Food intolerance, however, is triggered by several different mechanisms that are distinct from the immunological reaction responsible for food allergy.
Most allergies to foods begin in the first or second year of life. While some of these reactions may resolve over time (such as allergies to cow’s milk or eggs), other food allergies acquired in infancy (such as allergies to nuts or shellfish) typically persist throughout life. Children sometimes outgrow their food allergies, but adults usually do not loose theirs.
In children, the pattern is somewhat different from adults, and the most common foods that cause allergic reactions are eggs, milk, peanuts, and fruits, particularly tomatoes and strawberries.
The doctor makes his assessment with the help of a detailed history from the patient. He or she then confirms the diagnosis by the more objective skin tests, blood tests, or food challenges.
Avoiding the offending allergen in the diet is the primary treatment of food allergies. To do this, affected people need to read lengthy, detailed lists of ingredients on the label for each food they consider eating.
People who have had anaphylactic reactions to a food should wear medical alert bracelets or necklaces stating that they have a food allergy and that they are subject to severe reactions. These individuals also always should carry a syringe of epinephrine. Food allergies are serious, and should be treated as such.