Food Allergy: Suspect, Test, Avoid

March 15, 2006 -- After a 10-year effort, the nation's major allergy organizations have agreed on how best to diagnose and manage food allergy.

The new "practice parameters," from a panel of allergy experts, are a state-of-the-art guide on how to detect and treat food allergy.

Food allergies are common -- and commonly misunderstood by doctors as well as patients, says panel co-chairman Jay M. Portnoy, MD, who is chief of allergy, asthma, and immunology at Children's Mercy Hospital in Kansas City, Mo., and vice president of the American College of Allergy, Asthma & Immunology.

"I see patients all the time who go to a doctor, skin-test positive for lots of different foods, and are advised to avoid all of these foods," Portnoy tells WebMD. "It makes their life miserable. And it turns out they are not truly allergic to all these foods after all."

Portnoy's complaint rings true with patient advocate Anne Muñoz-Furlong, founder and CEO of The Food Allergy & Anaphylaxis Network (FAAN).

"Some parents never suspect food allergies until their child ends up at the emergency room -- where they might be told it is a food allergy, or they might not," Muñoz-Furlong tells WebMD. "Or if the child first has mild symptoms, like eczema, they may not realize it is a food allergy. And then the entire family suffers until a diagnosis is made and the food is eliminated from the diet."

The new guidelines appear in the March issue of the Annals of Allergy, Asthma & Immunology.

The Most Common Food Allergies

Food allergies occur when a sensitive person eats, inhales, or comes into contact with even tiny amounts of foods or food additives. These allergic reactions can be very mild or may be life-threatening.

Food allergies are becoming more and more common. There has been an increase in severe food allergy cases in the last 10 years, mostly driven by peanut and tree nut allergies.

In children, the most common food allergies are:

• Cow's milk
• Hen's eggs
• Peanuts
• Tree nuts
• Soybeans
• Wheat

In adults, the most common food allergies are:

• Peanuts
• Tree nuts
• Fish
• Crustaceans (such as shrimp, crabs, and lobster)
• Mollusks (such as clams, oysters, and mussels)
• Fruits
• Vegetables

In children, the foods most likely to cause severe allergic reactions -- anaphylaxis -- are peanuts, other legumes, tree nuts, fish, shellfish, milk, and eggs.

In adults, the foods most likely to cause anaphylaxis are peanuts, tree nuts, fish, and shellfish.

Symptoms tend to occur just after eating. They may include reddening of the skin, hives, itchy skin, swollen lips or eyelids, tightness of the throat, wheezing, difficulty breathing, coughing, vomiting, or diarrhea.

If you or your child has symptoms soon after eating, it's time to get tested.

Testing is the most controversial aspect of food allergy treatment. Just getting a skin test or a blood test isn't enough, says guidelines chief editor John J. Oppenheimer, MD, of the UMD-NJ New Jersey Medical School in New Brunswick.