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Experimental treatment for peanut allergy increases anaphylaxis risk, study finds

By Michael Nedelman, CNN

Updated 2230 GMT (0630 HKT) April 25, 2019

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<a href="http://www.cdc.gov/healthcommunication/toolstemplates/entertainmented/tips/allergies.html" target="_blank">More than 50 million people</a> in the United States suffer allergies each year, according to the Centers for Disease Control and Prevention. <br /><br />Snacking on nuts during the first year of life may reduce the risk of a nut allergy in children, studies show. Previously, parents of high-risk children had been advised to delay their introduction of peanuts.
Photos: Six ways to reduce allergy risk in kids
More than 50 million people in the United States suffer allergies each year, according to the Centers for Disease Control and Prevention.

Snacking on nuts during the first year of life may reduce the risk of a nut allergy in children, studies show. Previously, parents of high-risk children had been advised to delay their introduction of peanuts.
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Some studies have linked certain objects or behaviors to the possible reduction of allergy risk. One new paper, for instance, suggests that children who <a href="http://www.cnn.com/2016/07/11/health/allergies-thumb-sucking-nail-biting-children/">suck their thumbs or bite their nails</a> may have reduced risk of developing allergies.
Photos: Six ways to reduce allergy risk in kids
Some studies have linked certain objects or behaviors to the possible reduction of allergy risk. One new paper, for instance, suggests that children who suck their thumbs or bite their nails may have reduced risk of developing allergies.
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Many medical authorities, such as the American Academy of Allergy, Asthma & Immunology, <a href="https://www.aaaai.org/conditions-and-treatments/library/at-a-glance/prevention-of-allergies-and-asthma-in-children" target="_blank">recommend breast-feeding</a>, as breast milk provides important vitamins and nutrients to an infant. Some research shows that breastfeeding for at least four to six months may strengthen a baby's immune system and, as a result, be helpful in avoiding allergies.
Photos: Six ways to reduce allergy risk in kids
Many medical authorities, such as the American Academy of Allergy, Asthma & Immunology, recommend breast-feeding, as breast milk provides important vitamins and nutrients to an infant. Some research shows that breastfeeding for at least four to six months may strengthen a baby's immune system and, as a result, be helpful in avoiding allergies.
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Children's risk for developing allergies and asthma may be reduced when they are exposed to a pet, such as a dog or cat, in the household <a href="http://www.cnn.com/2011/HEALTH/06/13/pets.infants.allergies/">early in infancy</a>. Researchers suspect that early exposure to certain pet allergens or bacteria might strengthen the immune system.
Photos: Six ways to reduce allergy risk in kids
Children's risk for developing allergies and asthma may be reduced when they are exposed to a pet, such as a dog or cat, in the household early in infancy. Researchers suspect that early exposure to certain pet allergens or bacteria might strengthen the immune system.
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Research suggests that exposure to air pollution during the first year of a child's life increases the risk of developing allergies to food, mold, pets and pests. Therefore, fresh air might help in avoiding sensitivity to allergens.
Photos: Six ways to reduce allergy risk in kids
Research suggests that exposure to air pollution during the first year of a child's life increases the risk of developing allergies to food, mold, pets and pests. Therefore, fresh air might help in avoiding sensitivity to allergens.
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What a woman eats during pregnancy may reduce allergy risk in her child. Some studies show that a diet rich in vitamin D, such as milk, eggs or mushrooms, is associated with a reduced risk of the baby developing allergies.
Photos: Six ways to reduce allergy risk in kids
What a woman eats during pregnancy may reduce allergy risk in her child. Some studies show that a diet rich in vitamin D, such as milk, eggs or mushrooms, is associated with a reduced risk of the baby developing allergies.
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(CNN)An experimental treatment for peanut allergy may actually multiply someone's risk for serious allergic reactions -- much like the ones it aims to prevent, according to a new analysis.

The paper, published Thursday in the Lancet, found that people taking oral immunotherapy -- microdoses of peanut allergen meant to partly desensitize patients over time -- paradoxically had three times the rate of anaphylaxis compared with those taking a placebo. That risk jumped from 7.1% to 22.2%, based on an analysis of more than 1,000 patients across 12 trials. There were no deaths in any of the trials.
Those taking the treatment also reported more epinephrine use and saw roughly double the rate of other kinds of allergic reactions, the study showed. These findings were attributable to the treatment itself, not accidental exposures to foods, according to the authors.
    There's new advice to prevent food allergies in children
    There's new advice to prevent food allergies in children
    "There have been so many studies coming out about oral immunotherapy for peanut, there's sometimes conflicting information out there about its effectiveness and reliability," said study author and internal medicine physician Dr. Derek Chu, now a final-year fellow in clinical immunology and allergy at McMaster University in Ontario.
    Oral immunotherapy has shown promising results in some trials, but Chu said there may be a disconnect between how researchers measure outcomes in the controlled environment of a research study, versus what happens in the real world.
    Read More
    In clinical trials, researchers often rely on tests like an "exit food challenge," in which patients eat a small amount of peanut under a doctor's supervision. Food allergies, however, are not so predictable. Some patients had allergic reactions to doses of the therapy they'd previously tolerated, the new study says.
    "This protection that you get from going through immunotherapy -- that can change every day," Chu said. "If you exercise within two to four hours, or you take a hot shower, or you have an empty stomach, that can all change the way your body interacts with the food that you've supposedly been desensitized to.
    "So you can actually have an unpredictable reaction to the thing that's supposed to protect you."
    Peanut allergy, along with tree nut allergy, affects an estimated 3 million Americans or more. Experts say its prevalence is on the rise -- and in the majority of cases, it's lifelong.
    "We don't have any [approved] treatment for food allergy," said Dr. Alkis Togias, branch chief of allergy, asthma, and airway biology at the US National Institute of Allergy and Infectious Diseases. Togias was not involved in the new paper.
    "From our perspective as an agency that is responsible for research in the field, what it tells us is that we need to improve on the methods for treating food allergy, especially peanut allergy," he said.

    Hope vs. hype

    People with peanut allergies, as well as parents of kids with these allergies, have been holding out for a treatment that can offer some peace of mind. The idea behind oral immunotherapy is not necessarily to eliminate the allergy completely but to reduce the likelihood that accidental contact with peanuts could become serious or deadly.
    Experimental treatment helps 2 out of 3 peanut allergy sufferers, study finds
    Experimental treatment helps 2 out of 3 peanut allergy sufferers, study finds
    A study published in November, for example, found that two-thirds of its young patients were able to eat the equivalent of two peanuts with no severe reaction after a months-long regimen of powder-filled capsules.
    In the wake of studies like that one, Chu's analysis may be a wake-up call -- but it doesn't mean all hope is lost. Researchers are already looking for ways around the risks, he said.
    "Like the Tesla autopilot, for example, the first generation of any of these things was not perfect," said Chu, who carries an EpiPen for his own peanut allergy.
    Togias said there are a number of potential avenues for modifying how we approach oral immunotherapy, including changing the dose and taking it in combination with other medications, such as those that prevent allergic reactions.
    "The message is clear: We need to do better," Togias said. "But this is a first step."
    Even with additional risks, he added, patients might see a valuable trade-off: Some may want the option of taking such a treatment anyway because they can plan for an allergic reaction at home, while perhaps still offering a layer of security for peanut exposures that happen out-of-the-blue, away from home.
    "That's an important piece that is very personal," said Togias.
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      Experts say that more research is needed in order to improve upon the experimental treatment, look at different ways of delivering the therapy and discover whether there are certain groups of patients who benefit more than others.
      "There's hope that we will have something, but we have to separate hope from hype," Chu said. "This is a first crack at a new treatment."

      CNN's Susan Scutti contributed to this report.