METHODS: We prospectively collected symptom and severity data between June 2012 and December 2016 during an open OFC to diagnose food allergy or confirm tolerance acquisition. Anaphylaxis was defined according to the World Allergy Organization definition. We analyzed the risk factors of anaphylaxis during OFC.
RESULTS: A total of 2272 cases (median age: 3.5 years; egg: 1166 cases; milk: 589 cases; wheat: 388 cases; and peanut: 129 cases) were analyzed. Among 979 challenge-positive patients, anaphylactic reactions were observed in 334 cases. Multivariate analysis revealed that the risk factors for anaphylaxis to OFC were antigen sIgE for causative food (10-fold increase, adjusted odd ratio: 2.213, p < 0.001), a history of anaphylaxis to causative food (adjusted odd ratio: 1.522, p = 0.007), and a milk OFC (adjusted odd ratio: 2.066, p < 0.001). sIgE for causative food was confirmed as a risk factor of anaphylaxis to OFC for their respective foods.
CONCLUSIONS: The risk of anaphylaxis during OFCs increased with increasing specific IgE levels. Therefore, OFCs should be performed with caution for patients with high sIgE for causative food.