When Eric Nguyen was a toddler, just one bite of a piece of chocolate with nuts triggered a medical emergency.

His mother, Theresa, recalls, “Within maybe 15 minutes, he was itching like crazy, with hives from top to bottom.” Gasping for breath, Eric was rushed to the emergency room for a lifesaving shot of epinephrine.

For Eric’s little brother, mere cooking vapors did it.

“My husband was cooking shrimp, and I was folding the laundry, and Conrad was just running around, laughing and giggling, and I said to my husband, ‘His voice is getting higher pitched,’” says Theresa. “The next thing I knew he was flat on the floor, passed out.”

As it turned out, all three of Theresa Nguyen’s children -- Eric, now 17, Tessa, 15, and Conrad, 13 -- have allergies to such foods as peanuts, eggs, milk, and shellfish.

Adjusting for Allergies

Recognizing that those allergies can be life-threatening has motivated Nguyen to work closely with allergists, research causes and treatments for food allergies, learn to cook allergen-free foods, join support groups, and educate teachers and nurses in her children’s schools about adjusting to children with such allergies.

A growing number of families are making these adjustments. Studies show that eleven million Americans have food allergies and one-and-a-half million have a peanut allergy. According to the Food Allergy and Anaphylaxis Network (FAAN), from 1997 to 2002 the incidence of peanut allergy in children had doubled.

Duke’s Wesley Burks, MD, chief of pediatric allergy and immunology, says that food allergies typically appear between six and 18 months of age, since that is when many youngsters first sample foods such as peanut butter.

While children often outgrow certain food allergies, such as to eggs and milk, peanut allergies are usually for life.

Identifying Food Allergies

Not every reaction to a food is an allergy. A detailed clinical history is needed to differentiate viral gastroenteritis or food poisoning from food allergies.

“You need to find out the timing of the ingestion and the clinical symptoms,” Burks says. “Reactions to an allergen such as peanuts occur literally within minutes, not more than an hour or two, after ingestion. Food allergy symptoms are also isolated to the GI tract, the respiratory tract, and the skin.”

These symptoms include abdominal cramps, vomiting, diarrhea, skin symptoms like hives or itchy rash, difficulty breathing, and swelling of the lips or the eyes.

Also, “Food-allergy symptoms are reproducible,” Burks says. “Each time they have the food, they ought to have fairly similar symptoms.”

Taking a good clinical history means tuning in to the patient. “The thing I like as a parent is that Dr. Burks will talk with the kids himself,” Nguyen says. “I’m sitting there, but his conversation is with the kids, asking them for their contribution in terms of what’s bothering them or what they want help with.”

Diagnosis also depends on tests to measure the blood level of the immune protein IgE that triggers allergic reactions, and skin tests for sensitivity.

Nguyen’s family focuses on lifestyle adjustments. Conrad cannot even be in the same room with peanuts, so he takes his school lunch outside with a friend. Eric always carries his medicine and his EpiPen. And they all look out for each other; Tessa, for example, is learning to cook treats that her brothers can eat.

Changing attitudes is also critical -- among physicians, school administrators, and managers of any public facilities, says Nguyen, who has dealt with a physician who, despite detailed medical records, dismissed the idea that Conrad had a severe peanut allergy.

“Food allergies are real, and people with them should be treated no differently than somebody with diabetes or heart disease,” she says. “It’s a medical condition that we deal with as part of our life.”

Developing Treatments

While Nguyen fights false perceptions, Burks develops future treatments, including a vaccine.

After identifying the predominant allergy-triggering proteins in peanuts, Burks and collaborators are experimenting with altering the protein so that it will dampen the response of immune system cells, to avoid tripping the allergic alarm.

These experiments could lead to a vaccine in which the altered peanut protein could be given to allergy sufferers to desensitize them to peanuts.

More immediately, the researchers are clinically testing a therapy in which patients ingest tiny amounts of egg or peanut protein orally in an attempt to gradually desensitize their immune systems.

So far, patients have had minimal symptoms, Burks says. While initial protein doses are the equivalent of about a hundredth of a peanut, after three months, patients can consume an entire peanut each day as part of the treatment.

“We know we’re changing their immune systems in some way over those three months,” says Burks, “but only longer-term studies will tell us whether the tolerance is permanent.”

Burks cautions that there will be no magic bullet against food allergies. Immunotherapies, drug therapies, vigilance against allergens, and preparation for allergic attacks will always be part of the arsenal.

Still, says Burks, “I think that in five years we’ll have combinations of treatments that will prove effective.”

Tips for Dealing with Food Allergies

• Identify foods that hide allergens. Peanuts, for example, can be found in homemade chili, and some Asian foods may either contain peanuts or have been prepared in a wok that was used to cook peanuts.

• Develop a plan for an unexpected reaction. For example, be prepared to give the person an antihistamine and epinephrine using an EpiPen and immediately take them to the nearest emergency room. Allergic reactions are unpredictable; the same amount of allergen that caused only mild symptoms in the past can abruptly trigger severe anaphylaxis.

• Be extra vigilant with teens. Teens are at especially high risk of death, according to the Food Allergy and Anaphylaxis Network (FAAN). “They’re out with friends, they want to be like everybody else, they’re not expecting to eat a food that will cause a reaction, and they’re not carrying their epinephrine. And so one thing leads to the other,” says Anne Munoz Furlong, director of FAAN.

• Reach out. Support groups such as FAAN (www.foodallergy.org) offer teens and their families invaluable news and information as well as critical support.