The question of when to introduce peanut is one that many of my patients and friends ask me. I asked myself the same question when I had my first baby girl. At the time, I was completing a fellowship in allergy/immunology. There was no obvious answer based on the studies that had been done. I would tell patients, “there is not strong evidence either way; do what makes you comfortable. I cannot, based on the studies that have been done, recommend a definitive plan”. This was frustrating as I felt I could not guide patients either way.
Peanut allergy is a big deal. In 2010, it was estimated that about 2% of the population has it. Peanut allergy is the leading cause of anaphylaxis (a severe, systemic allergic reaction) and death related to food allergy in the United States.
What pediatric residents were taught to say about food introduction has varied throughout time. In 2000, the American Academy of Pediatrics (AAP) recommended that infants at risk for atopic disease refrain from feeding children until they were 3 years of age. In 2008, in the middle of my pediatrics residency, the AAP retracted this recommendation, stating that there was insufficient evidence to make this recommendation.
On February 23, 2015, a landmark study called Learning Early about Peanut Allergy (LEAP), was published in the New England Journal of Medicine, and also presented by its authors at the American Academy of Allergy, Asthma and Immunology (AAAAI). This study was prospective and randomized (both good things in terms of scientific study design), and clearly showed that early introduction (11 months of age or younger) of peanut dramatically decreases the risk of development of peanut allergy (approximately 70 to 80%). These results are impressive that they answer the question that many have wondered—when should peanut be introduced?
It is important to note that this study was only one study, and that it was done in a specific group of individuals—high risk patients, infants with severe eczema or egg allergy or both. It is unclear how the results would differ if this study was done in the general population. When the study participants were “introduced” to peanut, this was also a very specific and regimented schedule. It is unclear if a less regimented schedule of eating peanut would produce the same results. In addition, it is not clear if regular consumption of peanut were stopped, if the patient would continue to be tolerant of it. Also, this study only looked at peanut, and the same question remains regarding other common allergenic foods such as egg, milk, and tree nuts.
Dr. Gruchalla and Dr. Sampson (who I did my allergy fellowship training with), wrote an editorial in the New England Journal of Medicine in response to this study. In it, they state “…we believe that because the results of this trial are so compelling, and the problem of increasing prevalence of peanut allergy so alarming, new guidelines should be forthcoming very soon”.
Times are exciting in the field of food allergy. As a physician and mother, I hope that we will be able to provide answers to parents that will allow us to prevent food allergy in our kids. More studies more will need to be completed, but it is certainly helpful to have the LEAP so clearly demonstrate different outcomes based on if and when peanut is introduced.
If you are wondering about if and when your child should be introduced to peanut, please make an appointment! In the LEAP study, all of the high risk children who were introduced to peanut had a skin prick test first to assess for risk of an allergic reaction, so it is important to discuss with your broad certified allergist the best plan of action. Please call (949) 364-2900 for an appointment.
-by Faith Huang, M.D.