All about Food Allergies

People who have food allergies experience reactions soon after consuming a certain food. Three to four percent of adults suffer from food allergies, and a slightly higher percentage of children under the age of five experience reactions. There is no cure for food allergies, but some children outgrow the reactions as they grow older.

The immune systems of people with food allergies mistakenly identify certain foods as harmful substances. This triggers the release of antibodies that send histamine and other chemicals into the bloodstream. The result is a range of symptoms, including tingling or itching in the mouth, dizziness, lightheadedness or fainting, vomiting, diarrhea, abdominal pain, nausea, wheezing, trouble breathing, nasal congestion, hives, eczema, and itching or swelling of the tongue, lips, face, throat or other body parts. Some people experience a severe allergic reaction known as anaphylaxis. This life-threatening condition causes symptoms such as shock, rapid pulse, tightening of airways, loss of consciousness, and difficulty breathing due to swelling of the throat.

The most common triggers of food allergies in adults are the proteins in shellfish, eggs, peanuts, tree nuts, and other types of fish. Children most commonly experience reactions when exposed to eggs, wheat, tree nuts, peanuts and milk.

There is no standard test that can rule out or confirm food allergies. To make a diagnosis, a doctor may consider the patient's symptoms, conduct a physical examination, perform a skin test, or ask the patient to refrain from eating certain foods for a set period of time. The doctor may also use a blood test or oral food test to confirm allergies.

The best way to prevent allergic reactions is to refrain from contact with trigger foods, but there are medications that can reduce the symptoms of a reaction. Antihistamines, whether prescribed or over-the-counter, can help reduce symptoms such as hives or itching. More severe reactions require injections of epinephrine and emergency care. Many people with food allergies keep an epinephrine auto-injector with them at all times in case of exposure to a trigger food.

No treatment can prevent a reaction or completely relieve symptoms, but experimental treatments such as oral immunotherapy and anti-immunoglobin therapy are showing promise.