For Eric Nguyen, it only took a bite of candy to trigger a medical emergency.

Some 15 years ago, while on vacation in California, the toddler was given a piece of chocolate with nuts, recalls his mother, Theresa. "Within maybe 15 minutes, he was itching like crazy, with hives from top to bottom," she says. 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 at the time, and Conrad was just running around, laughing and giggling and having a good time, 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. And the recognition that those allergies can be life-threatening has made her a careful, proactive parent.

She has worked closely with their allergists, thoroughly researched causes and treatments for food allergies, learned to cook allergen-free foods, joined support groups, and educated teachers and nurses in her children's schools about the need to adjust to children with such allergies.

Her kids have had to adjust, too. 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.

Still, there are problems, sometimes from surprising directions. When the family first moved to North Carolina in 2002, the first physician Theresa saw shocked her with his dismissive attitude.

"He didn't want to believe that Conrad had food allergies, or that they were severe," she recalls. "I had all Conrad's records, and it was like the doctor didn't want to accept the paperwork that I had, or that anybody could have a peanut allergy."

Fortunately, she says, after that first disappointing encounter, she sought out Duke's Wesley Burks, MD, chief of pediatric allergy and immunology. In Burks, she says, she found a physician who is not only a research leader in food allergies, but an involved clinician.

"My kids love him, and the thing I like as a parent is that Dr. Burks will talk with the kids himself. I'm sitting there, but his conversation is with the kids, making them feel important and asking them for their contribution in terms of what's bothering them or what they want help with. I think at their age, it's very important to have that kind of a relationship, to feel like they're an important part of making decisions about their life."