Efficacy of very-low-dose oral food challenge in children with severe hen egg allergy: A retrospective, single-center case series

Abstract

Background

To avoid complete elimination of hen eggs (HE) from diet, we introduced a very-low-dose (VLD) oral food challenge (OFC) in patients with severe HE allergy in 2019. Herein, we investigated the efficacy of VLD HE OFC for achieving the full dose OFC.

Methods

Patients with an overt allergic reaction to LD (1/32 HE [≤100 mg]) or less, egg white (EW) protein within 6 months were included. In the VLD group, patients not achieving full-dose OFC (1/2 HE: 1600 mg EW protein) within 2 years were excluded. We retrospectively compared the rate of passing a full-dose OFC between patients who underwent a LD OFC before 2019 (LD group) and those who underwent a VLD OFC (1/100 HE: 32 mg EW protein) after 2019 (VLD group). The period for passing the full-dose OFC was evaluated using Kaplan–Meier survival analysis.

Results

We enrolled 411 and 111 patients in the LD and VLD groups, respectively. The median age at OFC initiation was 2.2 [1.5–3.6] and 2.1 [1.4–3.2] years in the LD and VLD groups, respectively. EW- and ovomucoid-specific IgE levels were 38.3 (12.5–72.9) and 21.0 (8.3–46.2) kU_A/L in the LD group and 49.8 [18.8–83.9] and 32.1 [15.6–67.8] kU_A/L in the VLD group, respectively. Over 4 years, the LD and VLD groups passed the full-dose OFC at rates of 70 and 95%, respectively, with significant differences (log-rank test, P < 0.001).

Conclusions

VLD HE OFC may contribute to passing a full-dose OFC in patients with severe HE allergies.