What is a food allergy?

A food allergy is an immune system response to a food that the body mistakenly believes is harmful. Once the immune system decides that a particular food is harmful, it creates specific antibodies to it. The next time the individual eats that food, the immune system releases massive amounts of chemicals, including histamine, in order to protect the body. These chemicals trigger a cascade of allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin, or cardiovascular system. Scientists estimate that approximately 12 million Americans suffer from true food allergies.

Although an individual could be allergic to any food, such as fruits, vegetables, and meats, there are eight foods that account for 90% of all food-allergic reactions. These are: milk, egg, peanut, tree nut (walnut, cashew, etc.), fish, shellfish, soy, and wheat.

What is the difference between food allergy and food intolerance?

Many people think the terms food allergy and food intolerance mean the same thing; however, they do not. A "food intolerance" is an adverse food-induced reaction that does not involve the immune system. Lactose intolerance is one example of a food intolerance. A person with lactose intolerance lacks an enzyme that is needed to digest milk sugar. When the person eats milk products, symptoms such as gas, bloating, and abdominal pain may occur.

A "food allergy" occurs when the immune system reacts to a certain food. The most common form of an immune system reaction occurs when the body creates immunoglobulin E (IgE) antibodies to the food. When these IgE antibodies react with the food, histamine and other chemicals (called "mediators") cause hives, asthma, or other symptoms of an allergic reaction.

What is the best treatment for food allergy?

Strict avoidance of the allergy-causing food is the only way to avoid a reaction. Reading ingredient labels for all foods is the key to maintaining control over the allergy. If a product doesn't have a label, allergic individuals should not eat that food. If a label contains unfamiliar terms, shoppers must call the manufacturer and ask for a definition or avoid eating that food.

What are the common symptoms of a reaction?

Symptoms range from a tingling sensation in the mouth, swelling of the tongue and the throat, difficulty breathing, hives, vomiting, abdominal cramps, diarrhea, drop in blood pressure, and loss of consciousness to death. Symptoms typically appear within minutes to two hours after the person has eaten the food to which he or she is allergic.

What is the best treatment for a food allergy reaction?

Epinephrine, also called "adrenaline," is the medication of choice for controlling a severe reaction. It is available by prescription as a self-injectable device (EpiPen® or Twinject®).

Is there a cure for food allergies?

Currently, there are no medications that cure food allergies. Strict avoidance is the only way to prevent a reaction. Most people outgrow their food allergies, although peanuts, nuts, fish, and shellfish are often considered lifelong allergies. Some research is being done in this area and it looks promising.