Gradual exposure desensitized some kids, but experts advise against trying on your own
SATURDAY, Feb. 27 (HealthDay News) -- Help may be on the way for children with serious peanut allergies, with two new studies suggesting that slowly increasing consumption might build kids' tolerance over time.
Both studies were small, and designed to build upon each other. They focused on peanut-allergic children whose immune systems were prompted to slowly develop tolerance to the food by consuming a controlled but escalating amount of peanut over a period of up to five years.
"The current goal with this work is not to allow patients with peanut allergies to consciously eat peanuts, but to prevent the severe symptoms that can occur should they have accidental ingestion," noted study co-author Dr. Tamara Perry, an assistant professor of pediatrics at the University of Arkansas for Medical Sciences College of Medicine in Little Rock, Ark.
"Of course the ultimate goal would be to promote tolerance that would allow these patients -- children and adults -- to eat peanuts," Perry added. "And the immunotherapy work being carried out now shows a lot of potential promise in that direction."
Perry and her associates are slated to present their findings Saturday at the American Academy of Allergy, Asthma & Immunology (AAAAI) meeting in New Orleans.
A peanut allergy can cause sudden breathing problems and even death. According to the AAAAI, more than three million people in the United States report being allergic to peanuts, tree nuts or both.
In one study, Perry and colleagues at Duke University placed 15 peanut-allergic children on a slow, but escalating oral dosage program, during which they consumed limited amounts of peanut food. Another eight peanut-allergic children were placed on a placebo regimen.
Among the children exposed to these carefully rising doses of peanut, negative reactions were mild to moderate, requiring medicinal intervention only a handful of times, the authors noted.
At the program's conclusion, a "food challenge" was conducted. The challenge revealed that while the placebo group could only safely tolerate 315 milligrams of peanut consumption, the 15 children who participated in the immunotherapy program could tolerate up to 5,000 milligrams of peanuts -- an amount equal to about 15 peanuts.
Having concluded that the dosage program afforded some measure of short-term "clinical desensitization" to peanuts, the research team then explored the program's potential for inducing long-term protection in a second trial.
Eight of the children who had participated in the oral dosing program for anywhere between 32 and 61 months were then subject to an oral peanut challenge four weeks after being taken off the dosing program.
All of the children -- at an average age of about four and a half years of age -- demonstrated lasting immunological changes that translated into a newly developed "clinical tolerance" to peanuts, the researchers said. And although the children continue to be tracked for complications, peanuts are now a part of their standard diets.
Yet despite the encouraging developments, Perry voiced caution about the findings.
"While the studies are very positive, it's still a research process that's going to take a lot of further study to allow us to tell which patients will be good candidates for this kind of therapy, as not all patients will be in terms of safety," she observed. "So consumers should realize that this is still a developing science and something that should only be done under strict supervision."
Dr. Scott H. Sicherer, a professor of pediatrics at Mount Sinai School of Medicine's Jaffe Food Allergy Institute in New York City, seconded that advice.
"I'm involved in this kind of research myself," he noted, "and it is very promising. But many open questions remain. Does this really cure the allergy, or just change the threshold while you're taking the daily treatment? There may be people who this does permanently cure, but there may be as many or more that it doesn't.
"So it's important to know that everyone involved in this kind of work stresses 'don't try this at home'," Sicherer said. "That could obviously be very dangerous. The work being done is being conducted in very rigorous, careful settings. And this is something that is not ready for prime-time yet."
That said, Dr. Clifford Bassett, a clinical instructor at New York University School of Medicine, medical director of Allergy and Asthma Care of New York and chair of the AAAAI's public education committee, said he's "extremely encouraged" by the studies.
"This builds upon what we know, and although this is preliminary with a small group of children, it's extremely exciting," he said. "It's always a positive when we have more information leading us to more strategies for reducing risk for a potentially life-threatening situation. And although we don't know if this type of approach could potentially help with respect to other food allergies, this is the kind of work that should ultimately go some ways towards easing the enormous anxiety shared by all parents of food-allergic children."
For more on peanut allergy, head to the Nemours Foundation.
SOURCES: Tamara Perry, M.D., assistant professor, pediatrics, University of Arkansas for Medical Sciences College of Medicine, and Arkansas Children's Hospital Research Institute, Little Rock, Ark.; Scott H. Sicherer, M.D., professor of pediatrics, Mount Sinai School of Medicine, Jaffe Food Allergy Institute, New York City; Clifford Bassett, M.D., clinical instructor, New York University School of Medicine, and medical director, Allergy and Asthma Care of New York, and chair, public education committee, American Academy of Allergy, Asthma & Immunology; presentations, Feb. 27, 2010, American Academy of Allergy, Asthma & Immunology annual meeting, New Orleans
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