[Background] The Japanese Pediatric Guideline for Food Allergy 2016 describes oral food challenge (OFC) doses as low, middle, and full. However, the influence of patient characteristics remains unclear. The present study evaluated the utility of specific IgE (sIgE) in the selection of the total egg amount in each dose.

[Method] The total volume of 20-min boiled egg whites was adjusted according to the egg white-sIgE levels for OFCs performed on infants who have never ingested hen's eggs or who are suspected of having allergies to hen's eggs.The OFC positive rate, egg white and ovomucoid (OVM) sIgE levels, and area under the curves (AUCs) were compared among doses.

[Result] The OFC positive rates in the low, middle, and full doses were 66.6, 27.9, and 8.3%, respectively. The AUC values of egg white and OVM sIgE were 0.61 and 0.65 (P=0.71), 0.58 and 0.69 (P<0.05), and 0.92 and 0.91 (P=0.89) for the low, middle, and full doses, respectively.

[Conclusion] Adjusting the total amount of egg white according to the egg white-sIgE in the OFC may be used as an effective index of egg allergy.