Peanut allergy: Can a child outgrow it?

Yes. About 20 percent to 25 percent of children with peanut allergy will outgrow it. But there is a small risk it will return. Peanut allergy affects 1 percent to 2 percent of young children and is the most common cause of anaphylaxis, a life-threatening allergic reaction.

It's difficult to predict which children will outgrow peanut allergy. Some research suggests that children with lower levels of peanut allergy-specific antibodies (IgE) may be more likely to outgrow peanut allergy than children with higher levels of these antibodies. IgE is measured by a blood test.

Even when a child appears to outgrow peanut allergy, there is a small risk it will recur. A study published in November 2004 suggested that the way to reduce the risk of recurrence is to encourage the child to eat peanuts on a regular basis. This may seem odd advice to parents who have drilled a fear of peanuts into their children. But the study found peanut allergy was much less likely to return in children who ate peanuts at least once a month after developing a tolerance for them than in children who largely avoided peanuts.

How do you know if your child has outgrown peanut allergy? Children with known peanut allergy should be re-evaluated by a board-certified allergist before discontinuing any preventive or avoidance measures. Even if it is determined that a child has outgrown peanut allergy, doctors still recommend that the child continue to carry injectable epinephrine in case the allergy returns.