In a pivotal trial, published last year in the New England Journal of Medicine, European researchers from the Learning Early About Peanut Allergy (LEAP) study team presented data which fundamentally shifted existing concepts surrounding peanut allergy. Early dietary avoidance of peanut had previously been advocated as a method to delay the onset of peanut allergy. Despite this, the incidence of allergies has continued to rise worldwide. In LEAP, 640 infants at high risk for developing peanut allergy (those with eczema and/or egg allergy) were selected to either consume or avoid peanuts until they reached 5 years (60 months) of age. Results from this study showed a 70-86% risk reduction in the future development of peanut allergy in children from the early consumption group. One of the questions left answered by LEAP was what would happen if these same children stopped consuming peanut on a regular basis?
Enter, LEAP-On. 556 participants from the initial LEAP study were observed from the 60 month mark for 12 months after being instructed to avoid peanuts. Peanut allergy at 72 months was significantly more prevalent among children in the original peanut-avoidance group than those who had initially been consuming peanut on a regular basis. Although three new cases of allergy did develop in the early peanut-consumers, there was no significant increase in the prevalence of allergy in this group after 12 months of not eating peanuts. This indicates that after achieving tolerance to peanuts at age 5, children may not need to continue to eat them regularly to prevent development of allergy.
To peanut or not to peanut?
These findings provide insights into future strategies of preventing peanut allergies and clinical implications of maintaining immune tolerance. Obvious questions that now arise are how long tolerance can potentially be maintained and the effects of “ad lib” peanut consumption.
Given that peanut-associated anaphylaxis can potentially lead to fatal reactions, none of the above interventions should be attempted without first consulting with your Allergy Partners allergist.
Dr. Nabeel Farooqui
Allergy Partners of Central Indiana