Rates of New Peanut Allergy and Discontinuation Following Introduction in High-Risk Infants.

Background: Peanut introduction guidelines recommend that infants with severe eczema and/or egg allergy consume 6 g of peanut protein weekly to prevent peanut allergy. Rates of new peanut allergy after introduction and adherence remain under study.

Objective: To determine compliance with peanut introduction guidelines, rates of new peanut allergy, and reasons for discontinuation of peanut consumption in a cohort of high-risk infants.

Methods: A prospective cohort of 4- to 11-month-old high-risk infants (defined as moderate-severe eczema or non-peanut food allergy or a first-degree relative with peanut allergy) with no prior peanut exposure who were determined to not be peanut allergic were recommended to introduce 6 g of peanut protein weekly. Participants were followed to 30 months with 2 in-person visits and monthly questionnaires.

Results: Two hundred seventy-seven infants were followed. At last follow-up, 245 (88%) were consuming some peanut protein with median weekly consumption of 3 g (interquartile range: 1-5 g). New peanut allergy developed in 6 (2%), with 2 of those cases consistent with food protein-induced enterocolitis syndrome. Fear of reaction in another household member was the most common reason for peanut discontinuation. Reactions to peanut after introduction in the index infant occurred in <2% of peanut-allergic siblings and in 20% of peanut-allergic parents.

Conclusion: We found low rates of new peanut allergy and generally low rates of peanut discontinuation after introduction in our high-risk cohort. However, families of high-risk infants require significant support with introduction, especially those with another peanut-allergic member.