Food Allergens

A food allergy, or hypersensitivity, is an abnormal response to a food triggered by the immune system. While many people often have gas, bloating, or another unpleasant reaction to something they have eaten, it is not considered an allergic response. Such a reaction is thought to not involve the immune system and is called food intolerance. Only about 2 percent of adults and up to 6 percent of children younger than three years of age in the United States have a true food allergy. It is critical for people who have food allergies to identify them and to avoid the foods which cause the allergic reaction. Some foods can cause severe illness and, in some cases, a life threatening allergic reaction which can constrict airways in the lungs, severely lower blood pressure, and cause suffocation by the swelling of the tongue or throat.

Currently, the only way to treat food allergies is to avoid the foods which trigger reactions. Even the most diligent label readers are likely to be inadvertently exposed to proteins that elicit an allergic response at some point. Anaphylactic allergic reactions can be fatal even when they begin with mild symptoms such as a tingling in the mouth and throat or gastrointestinal discomfort. Antihistamines and bronchodilators can be used to treat less severe symptoms. Food manufacturers and consumer groups are working with the Federal Drug Administration to increase public awareness of the seriousness of food allergen reactions and to ensure that allergens are appropriately labeled in food products.

Food allergy reactions can vary from person to person. Some reactions can be very mild and only involve one part of the body. Other reactions may be more severe and involve more than one part of the body. Reactions can occur within a few minutes or up to a few hours after contact with the food. A serious allergic reaction with widespread effects on the body is known as anaphylaxis. This sudden and potentially life threatening allergic reaction involves two or more body areas. In addition, there may also be swelling of the airway, serious difficulty with breathing, a drop in blood pressure, loss of consciousness, and in some cases, even death. The primary caregiver will look for any other condition that could cause the symptoms. If the doctor suspects a food allergy, the patient will likely be referred to an allergy specialist, who will ask in depth questions, perform a physical exam, and perform tests to help make a diagnosis

Diagnosing a food allergy can be a challenge for most doctors. First the doctor must determine if the patient is having an adverse reaction to specific foods. The doctor makes this assessment with the help of a detailed history from the patient, the patient's dietary diary, or an elimination diet. The doctor then confirms the diagnosis by the more objective skin tests, blood tests, or food challenges. The dietary history is the most important diagnostic tool. The physician interviews the patient to determine if the facts are consistent with a food allergy. If the patient's history, dietary diary, or elimination diet suggests that a specific food allergy is likely, the doctor will then use tests, such as skin tests, blood tests, and a food challenge, which can more objectively confirm an allergic response to food.