Timing of symptom onset during 60-min interval oral food challenges in children

Abstract

Background: Dosing intervals are important in determining oral food challenge (OFC) safety; however, the optimal interval remains unclear. This study aimed to investigate symptom onset time in low-dose OFCs, utilizing 60-min intervals, involving four common pediatric allergens.

Methods: We retrospectively analyzed symptom onset time for low-dose OFCs involving two doses at 60-min intervals in children allergic to egg, milk, wheat, and peanut. Challenges were performed to diagnose allergies or confirm tolerance acquisition. Total challenge doses were 250, 102, 52, and 133 mg of egg, milk, wheat, and peanut proteins, respectively. OFCs were positive when objective symptoms were observed.

Results: Of the 1610 children (379, 430, 431, and 370 had allergies to egg, milk, wheat, and peanut, respectively), 552 (34 %) were OFC-positive: 103 (27 %) with egg allergy, 210 (49 %) with milk allergy, 105 (24 %) with wheat allergy, and 134 (36 %) with peanut allergy. The median (interquartile range) onset times of symptom were 45 (29-60) min for egg allergy, 30 (15-45) min for milk allergy, 42 (30-55) min for wheat allergy, and 30 (14-45) min for peanut allergy after the first dose, and 35 (17-60) min for egg allergy, 30 (15-45) min for milk allergy, 35 (24-55) min for wheat allergy, and 25 (15-40) min peanut allergy after the second dose. Late-onset reactions (≥30 min) occurred in 64 % of first doses and 54 % of second doses across all allergens.

Conclusions: OFC dose intervals at >30 min are necessary to ensure safety and accurate assessment.