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What is a food allergy?

A food allergy is the body's reaction when the immune system gets confused and attacks things in food that aren’t harmful. When people have a food allergy, the B-cells in the immune system get confused and think that antigens on food are the same as germ antigens. An antigen that people are allergic to is called an allergen. The B-cells fire antibodies at the food and call for backup. Then histamine and other signals make the blood vessels wider and more white blood cells rush in. This is called an allergic reaction.

A food allergy happens when the immune system responds to food proteins in one of two main ways that lead to troubles.

Sudden allergic reactions generally begin minutes to an hour or two after the food is eaten. The typical symptoms include any or a combination of: hives (like mosquito bites), skin swelling, itchy rashes, throat tightness, trouble breathing, wheeze, cough, stomach pain, vomit, diarrhea and signs of poor blood circulation (pale, dizzy, confusion, losing consciousness). These allergic reactions are caused by our body making a protein called IgE antibody. However, not everyone making these proteins have reactions to foods.

Another way that the immune system can “attack” food protein is by having various immune cells involved leading to inflammation. This can lead to persistent rashes or gut problems (pain, vomit, diarrhea, poor growth, etc). These same symptoms are caused by many different triggers and illnesses so your doctor must consider many possibilities.

People with food allergies have immune systems that mistakenly react to certain foods as an invader (like a virus), causing an immune response. Common food allergens include cow's milk, eggs, peanuts, wheat, soy, shellfish and tree nuts. You are more likely to develop a food allergy if someone else in your family has allergies.

Symptoms of a food allergy include hives, itchiness and tingling or swelling of the skin, tongue and/or mouth. In severe cases, a person may develop anaphylaxis, which is a serious reaction that causes difficulty breathing, drop in blood pressure and loss of consciousness. This is a medical emergency and requires immediate medical attention.

Food allergies are an important health concern affecting children and adults. A food allergy is an adverse health effect arising from an immune response that involves a specific IgE antibody. This immune response should recur on exposure to a certain food. An example is a child who, when exposed to milk protein, develops hives.

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A food allergy is an immune reaction caused by exposure to certain types of foods. In those with food allergies, the body incorrectly identifies certain foods as harmful and produces chemicals to "protect" the body. These chemicals and/or immune responses are responsible for the symptoms commonly experienced during an allergic attack. These symptoms can range from mild abdominal pain and gas to life-threatening swelling of the airway.

A food allergy occurs when the immune system mistakenly attacks a food component. Ingestion of the offending food may trigger the sudden release of chemicals, including histamine, resulting in symptoms of an allergic reaction. The symptoms may be mild (rashes, hives, itching, swelling, etc.) or severe (trouble breathing, wheezing, loss of consciousness, etc.). A food allergy can be potentially fatal.

Ms. Vandana  R. Sheth
Nutrition & Dietetics Specialist

According to the Food Allergy & Anaphylaxis Network, "Food allergy occurs when the immune system mistakenly attacks a food protein. Ingestion of the offending food may trigger the sudden release of chemicals, including histamine, resulting in symptoms of an allergic reaction. The symptoms may be mild (rashes, hives, itching, swelling, etc.) or severe (trouble breathing, wheezing, loss of consciousness, etc.). A food allergy can be potentially fatal. Scientists estimate that as many as 15 million Americans suffer from food allergies."

Food allergies are allergic reactions to foods—most often milk, eggs, soy and wheat, peanuts and tree nuts, fish and shellfish. These account for a large number of emergency room visits and a few deaths each year in the United States. Exposure to these foods may cause adverse reactions in the digestive or respiratory systems, on the skin or, in the most severe cases, anaphylactic shock or death.

Ms. Ashley Koff, RD
Nutrition & Dietetics Specialist

Anyone who has the unfortunate experience of consuming a problematic food knows that it's an energy killer. Food allergies, for instance, are on the rise today, especially among children. According to the U.S. Centers for Disease Control and Prevention, the number of kids with food allergies has gone up. This term can be misconstrued, however. A true food allergy is an abnormal response to food that is triggered by a specific reaction of the immune system and expressed by certain, often characteristic, symptoms. Other kinds of reactions to foods that are not food allergies include food intolerances (such as lactose intolerance), food poisoning, and toxic reactions.

Mom Energy: A Simple Plan to Live Fully Charged

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Dr. Leigh Vinocur, MD
Emergency Medicine Specialist

Allergies, in general, are an overreaction of our immune system. With food allergies, our immune system mistakes food proteins as a foreign invading germs, causing hives, rash, even trouble breathing and potentially deadly low blood pressure with shock and anaphylaxis. The most common food allergies are to milk, eggs, peanuts, tree nuts (almonds, cashews, walnuts), fish and shellfish, as well as soy and wheat. There is no cure for food allergies. You need to carefully manage your food allergies with prevention and vigilance.

According to the American Academy of Allergy, Asthma and Immunology, most children outgrow milk, egg, soy and wheat allergies. About 10 to 20 percent of kids will even outgrow peanut or tree nut allergies.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.