Food allergies in children have been on the rise for years. Estimates show that between 2 and 10 percent of all kids in the United States have at least one, and peanut allergies are thought to be the most common. 

We recently received this question from a viewer:

Dear Dr. Manny,  
My 6-year-old son was born with a peanut allergy, but a blood test now shows he's no longer sensitive to it. How is this possible? And is it really OK to give him peanuts again?  
Thanks,
Jenny

Thank you for your email.

Food allergies—and peanut allergies in particular—can be life-threatening, so I understand your concern.

While the cause of food allergies is unknown, with some experts pointing to the environment and others pointing to weakened immune systems, the definite cause for a rise in food allergies in the past decade or so isn’t known. A study published in the February edition of the journal Nature, however, suggests that genes may play a role in the development of peanut allergies specifically.

Allergies linked to dairy, like milk and cheese, are also common. But kids tend to grow out of these more often than they do peanut allergies. That said, allergist and immunologist Dr. Clifford Bassett, founder and medical director of Allergy and Asthma Care of New York, says it is possible to grow out of peanut allergies, as may be the case with your son. But Bassett, a top-ranked allergist in New York, urged caution before introducing peanuts to a person who has been previously diagnosed with an allergy to the food.

"It is never 100 percent safe to reintroduce a food that you suspect you or your child has as an allergy to— particularly a peanut allergy responsible for severe, life-threatening reactions,” Bassett told Fox News. “Always work with a trained professional— a board-certified allergist that is equipped to properly evaluate you, gauge the risks, and treat you correctly so that you're out of harm's way."

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