Background: The ultrarush protocol is an attractive approach in the buildup phase of venom immunotherapy (VIT-UR). However, the degree of risk of VIT-UR in children remains unknown. The objective of this study was to compare the safety of VIT-UR in children and adults.

Methods: We performed a study based on prospectively gathered medical records of children and adults with hymenoptera venom allergy treated with VIT-UR in 3 allergy centers in Poland.

Results: The study population comprised 134 children (mean [SD] age, 12.6 [3.7] years; males, 70.1%) and 207 adults (mean age, 42.4 [14.0] years; males, 47.8%). The number of children in the subgroups of bee venom (BV) allergy and wasp venom (WV) allergy were comparable, although sensitization to WV was more predominant in the adult group (70.1%). Skin reactivity to both venoms was more common in children than in adults (P<.001); however, children had higher concentrations of total IgE and specific IgE to BV (both P<.001). Systemic allergic reactions (VIT-SARs) occurred in 6.2% of the patients (3.7% in children and 7.7% in adults; nonsignificant). In adults, SARs occurred more frequently in patients treated with BV than WV extracts (21.4% vs 2.6%; P<.001). The same pattern was observed in children (7.2% vs 0%; P=.058). However, VIT-SARs to BV were less frequent in children than in adults (P=.034). Similarly, no significant relationship was noted between children and adults receiving WV VIT (2.6% vs 0%; nonsignificant). The severity of VIT-SAR did not differ between children and adults.

Conclusions: VIT-UR is safer in children. Age below 18 is not a risk factor for VIT-SARs.

Key words: Adults. Children. Insect venom immunotherapy. Systemic adverse reaction.