The natural progression of peanut allergy: Resolution and the possibility of recurrence.

Abstract

It was once thought that peanut allergy is a lifelong problem. We previously reported that about 20% of children outgrow their peanut allergy and that more than 60% of patients with a peanut-IgE level of 5 or less passed an oral challenge. The goal of this study was to further describe the natural progression of peanut allergy by reviewing patients who have undergone oral peanut challenges since the previous study. Patients with peanut-IgE levels of 5 or less were offered a peanut challenge. Those who passed were further evaluated by questionnaire to assess reintroduction of peanut into their diet and whether any recurrence has occurred. Eighty-four patients were evaluated, and 80 underwent complete analysis. Fifty-five percent with peanut-IgE levels of 5 or less and 63% with peanut-IgE levels of 2 or less passed challenges, compared to 61% and 67%, respectively, in our previous study. The 4 additional patients passed peanut challenges in this study after previously failing. Three patients with initial anaphylactic reactions and 2 patients with initial peanut-IgE levels greater than 70 passed their challenge. Follow-up of those who passed in both studies showed that the majority of patients reintroduced peanut into their diet, but that continued label reading, infrequent/limited ingestion, and aversion to peanut were all common in this population. Two patients had suspected subsequent reactions to peanut after passing their challenge. Patients with a history of peanut allergy and peanut-IgE levels of 5 or less have at least a 50% chance of outgrowing their allergy. Recurrence of peanut allergy may occur but appears to be uncommon.