FRIDAY, Aug. 3 (HealthDay News) -- Kids with a serious food allergy generally have to steer clear of the offending food, but methods now under development could change that common scenario.

More than 3 million American youths -- about one of every 25 -- have a food allergy of some sort, usually to milk, eggs or peanuts, according to U.S. government statistics. For them, "avoidance has been the mainstay of treatment for a long time," said Dr. William Silvers, an allergist in private practice in Vail, Colo., and a spokesman for the American College of Allergy, Asthma and Immunology.

"Now what we're seeing is an increased interest in oral immunotherapy," Silvers said. "This means giving small and slowly increased doses orally of foods that children are allergic to, and building up the amount ingested over time to desensitize the child to the food so they can tolerate it."

That doesn't come string-free, though. Dr. Carla Davis, an allergist at Texas Children's Hospital in Houston, noted that once children have been desensitized to a certain food, they have to continue eating it regularly or they'll become allergic to the food again.

"There isn't a maintenance of tolerance if you avoid the foods," she explained.

Along with desensitization, another potential new treatment for food allergies is a drug called omalizumab (Xolair). Silvers said that it works by blocking the activity of the allergy-causing substance known as immunoglobulin E (IgE) so that an allergic reaction never starts.

However, the food allergy would come back if a person were to stop using the drug, which is currently available only in an injectable form and has not been approved by the U.S. Food and Drug Administration for use in children younger than 12.

Some researchers, though, think that a combination of the two treatments might be better than either alone. Early reports from a very small study found that nine of 11 children who were given Xolair and then desensitized to milk were able to consume up to 12 ounces of dairy a day without a reaction.

Davis said that researchers also are testing herbal formulations and that one particular combination of nine herbs was able to prevent a serious allergic reaction, known as anaphylaxis, in mice. "It's another one of the treatments that may be up-and-coming," she said, though there's no evidence in humans yet.

What has been proven true, though, is that many kids simply outgrow their food allergies, even some of the most deadly ones. Davis said that as many as one in five youngsters may outgrow an allergy to peanuts but that allergies to eggs, milk, soy and wheat are most often outgrown. In general, peanuts, tree nuts and seafood allergies tend to stay with children as they grow, she said.

To know whether a child has outgrown a food allergy requires repeated skin and blood tests, Silvers said. "If IgE levels in the blood decrease over time, or if skin testing comes back negative or a very small reaction, a child or adult can be given a food challenge to see if they'll react," he said.

To be safe, though, the testing "must be done under a physician's supervision," Davis said, because a serious reaction could occur if the youngster has not outgrown the allergy.

For kids with lingering food allergies, Silvers recommended that the child or parent always carry the antihistamine Benadryl and an epinephrine injection pen. If it's suspected that the child accidentally ingested an allergy-inducing food, the youngster should take the antihistamine right away. If the allergic reaction worsens, administer the epinephrine and get to an emergency room as quickly as possible.

It's important to go to the hospital after a serious allergic reaction, Davis said, because there can be a second wave to the reaction about four to six hours later.

Many children have their own epinephrine pens at their school nurse's office. In Chicago, the public school system recently decided to take the next step and keep a supply of epinephrine pens in every school, and train school personnel in their use, so that they're prepared for any serious allergic reactions.

"This is a good idea because about one in five children have their first serious reaction in school," Davis said.

For those living with food allergies, Davis said, it's important to find a balance between being vigilant and being overanxious. Parents should be "prepared for a reaction, but shouldn't expect one all the time," she said. "Some parents become extremely anxious about the contact their child may have with food. Health vigilance is important, but so is quality of life."

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about treating food allergies.

A related article looks at how one family copes with multiple food allergies.

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