Approximately 5 million Americans, 5 - 8% of children and 1 - 2% of adults, have a true allergy to one or more food items. These can be merely annoying -- or they can be life-threatening. Knowledge about food allergies can help save lives.

A food allergy is a reaction of the body’s immune system to an ingredient in a food, usually a protein. It can be a serious condition and should be properly diagnosed by a board-certified allergist. True food allergies can take many forms. The eight most common food allergens -- milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish -- cause more than 90% of all food allergic reactions. However, many other foods have been identified as allergens, and only an allergist can determine what food you are allergic to.

Symptoms of food allergy differ greatly among individuals, and even within the same person during different exposures. Common symptoms include skin irritation, such as rashes, hives and eczema; gastrointestinal symptoms, such as nausea, diarrhea, and vomiting; and sneezing, runny nose, and shortness of breath.

Less common but far more problematic is the severe reaction called anaphylaxis. Anaphylaxis is a rare but potentially fatal condition in which several different parts of the body experience allergic symptoms. These may include itching, hives, swelling of the throat, difficulty breathing, lowered blood pressure and unconsciousness. Symptoms usually appear rapidly, sometimes within minutes of exposure to the allergen, and can be life-threatening. Immediate medical attention is necessary when anaphylaxis occurs, including a trip to the emergency room in many cases. Quick administration of certain medications is essential. In fact, persons who are severely allergic should have an emergency allergy kit.

If you believe you may be allergic to a certain food, you should see an allergist to obtain a diagnosis. The diagnosis is based upon your medical history, a food diary you will keep, skin-prick tests, blood tests and food challenges. Once your diagnosis is complete, your allergist can help develop a response plan to manage allergic reactions.

There is no cure for a food allergy -- complete avoidance of that food is critical. Since most reactions occur when you are away from home, it is important to explain your situation clearly to your host or food server. Always examine food labels to determine the presence of allergens. And keep an emergency kit with you at all times. If you experience a severe reaction to a food, call 911 immediately and execute the response plan you and your doctor have developed.

Sources:  The International Food Information Council and the American Academy of Allergy, Asthma, and Immunology

The Health Alliance provides emergency departments throughout the Tristate at its hospitals:  The Christ Hospital, The University Hospital, The St. Luke Hospitals (East and West), The Jewish Hospital and The Fort Hamilton Hospital.