BACKGROUND: OBJECTIVE: METHODS: RESULTS: A total of 436 of 1273 OFCs resulted in a reaction (34%). Epinephrine was administered in 50 challenges (11% of positive challenges, 3.9% overall) for egg (n = 15, 16% of positive OFCs to egg), milk (n = 14, 12%), peanut (n = 10, 26%), tree nuts (n = 4, 33%), soy (n = 3, 7%), wheat (n = 3, 9%), and fish (n = 1, 9%). Reactions requiring epinephrine occurred in older children (median, 7.9 vs 5.8 years; P < .001) and were more often caused by peanuts (P = .006) compared with reactions not treated with epinephrine. There was no difference in the sex, prevalence of asthma, history of anaphylaxis, specific IgE level, skin prick tests, or amount of food administered. Two doses of epinephrine were required in 3 of 50 patients (6%) reacting to wheat, cowʼs milk, and pistachio. There was 1 (2%) biphasic reaction. No reaction resulted in life-threatening respiratory or cardiovascular compromise. CONCLUSION