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A 10-year-old boy has been cured of his peanut allergy, one of the first instances of a child being alleviated of the condition, according to research presented at the American College of Allergy, Asthma and Immunology's (ACAAI) Annual Scientific Meeting.

Peanut allergies affect approximately 3 million school aged children in the United States, and they are the most common cause of fatal food anaphylaxis – a severe full-body allergic reaction that often leads to airway blockage and cardiac arrest.

While some children eventually outgrow conditions like peanut allergies, many spend their lives carefully avoiding their allergens. Though there are no known treatments for sufferers of peanut allergies, doctors believe they have successfully cured one child of a peanut allergy he developed in 2003.

When Dr. Steven Weiss, an allergist and fellow of the American College of Allergy, Asthma and Immunology, first encountered the patient, he was 15 months old and had suffered an allergic reaction after consuming a peanut product. Despite the serious nature of the boy’s allergy, his parents were able to manage his condition with careful surveillance.

“We kept him well by avoiding it. We kept something called an EpiPen around, and he never had any accidental ingestion,” Weiss told FoxNews.com.

According to Weiss, the road to this child’s cure began with the onset of another scary, and potentially deadly condition. At age 4, he was diagnosed with a form of acute lymphocytic leukemia (ALL).

Though the child initially received successful chemotherapy treatments, he later experienced a relapse, necessitating a bone marrow transplant. Luckily, the transplant was successful, and the boy went into remission from his disease.

Two years later, the boy visited Weiss again. Based on previous research, Weiss suspected that it was possible that the child’s bone marrow transplant had cured him of his peanut allergy.

“There is published data (indicating that) someone who gets a liver transplant or bone marrow transplant might develop the allergies that the (donor) had,” Weiss said. “Let’s say you have a peanut allergy, potentially that could be transferred by marrow transplant to the person receiving (the transplant). This is the opposite.”

Weiss’s suspicions proved correct, and after initial testing revealed no signs of a remaining peanut allergy in the boy, Weiss administered an “oral challenge.” The gold standard of food allergy testing, the oral challenge calls for patients to be slowly exposed to small amounts of their allergen to see how they react.

“He came into the office, and we gave him peanut butter,” Weiss said. “He did not have any reaction. He was able to go home and reintroduce that into his diet. He no longer needs an EpiPen."

Though nobody knows exactly why some people develop allergies and others do not, researchers know that allergic reactions occur when a person’s immune system stops recognizing certain foods as being “safe” to consume. However, when the boy received his bone marrow transplant, his immune system was replaced with someone else’s – curing him of his peanut allergy.

Researchers hope that by studying cases like this one, they may gain more insight into the factors that contribute to the development of allergies in individuals. However, bone marrow transplants aren’t a feasible treatment option for others suffering from peanut allergies.

“It’s not a treatment we could see in the future; bone marrow transplants are risky procedures,” Weiss said. “It was the silver lining to his cancer.”