To test or not to test: Lessons learned from screening infants for peanut allergy

Background: In recent years, there has been a trend to forgo screening for peanut allergy (PA), even in infants at high risk. This study aimed to better understand the implications of screening for PA before peanut introduction. Objective: We sought to characterize the outcomes of infants who underwent PA skin testing in a tertiary-care allergy clinic. Methods: We performed a retrospective chart review between July 1, 2017, and December 31, 2020, on all infants seen in the allergy clinic who had a peanut skin-prick test and recorded their demographic and clinical characteristics as well as outcomes with regard to PA and tolerance. Results: Twenty percent of the infants screened were identified as having PA. Infants with a PA were more likely to be older at the time of testing, more likely to have another allergist-diagnosed immunoglobulin E (IgE) mediated food allergy, and more likely to have a prescription for a stronger (class VI or stronger) topical steroid. When conducted, oral food challenge was safe, with the majority of infants being treated with observation or antihistamines. A large percentage of infants with a PA developed tolerance during the follow-up period. Conversely, 5% of the infants who were initially tolerant developed a new PA. Conclusion: PA is associated with severe atopic dermatitis and other IgE-mediated food allergies. However, it is unclear if there is a benefit from screening infants before peanut introduction. It is important to monitor for resolution in the infant population.