Reactions Among Children Undergoing Egg Oral Immunotherapy (OIT)

To assess the safety of egg oral immunotherapy (OIT) in children allergic to hen’s egg and identify risk factors associated with reactions. Sixteen children with physician diagnosed egg allergy and a positive egg challenge underwent egg OIT at the Montreal Children’s Hospital (MCH). Reactions occurring throughout OIT were recorded and categorized as allergic or anaphylactic (single versus multiple organ system(s) involvement respectively, according to the NIAID anaphylaxis definition) and were graded by severity according to the Muraro et al. system (Allergy, 2007 62(8):857-71). Reactions risk factors were determined via the generalized estimating equation logistic regression. During OIT, 16 children (median age: 12), took a total of 5953 doses, 134 doses triggered oral reactions and 603 caused systemic reactions, no reactions were severe. Seventy-two (1.21%) doses resulted in anaphylaxis, including, 58 mild and 14 moderate reactions. Three anaphylactic reactions were treated with epinephrine during up-dosing at the MCH. Fifteen of 16 children experienced anaphylaxis at least once, though 2 children had 37 (51.39%) of the anaphylactic reactions. Of the allergic reactions, 459 were mild and 72 were moderate. The most common symptoms were abdominal (16/16) and oral (12/16) discomfort, and skin symptoms (13/16). Older children were less likely to experience anaphylaxis [OR: 0.78, (95%CI: 0.64-0.94), p=0.010] or any systemic reaction [OR: 0.83, (95%CI: 0.70-0.98), p=0.027] during OIT. Males (7/16) were less likely to experience systemic reactions [OR: 0.29 (95%CI: 0.17-0.49), p<0.001]. Egg OIT is safe to carry out under careful supervision, especially in older boys.