Anaphylactic Reactions During Bee Venom Immunotherapy in the Paediatric Population.

Aim: A retrospective study will review episodes of anaphylaxis during bee venom immunotherapy (BVIT) in children, any modifications made to the dosing schedule, and the subsequent outcomes over a nine-year period in Western Australia.

Methods: Patient demographics, dose eliciting anaphylaxis during BVIT, modifications made to BVIT regimen following anaphylaxis (i.e., continuation, modification, or cessation), and the subsequent outcomes were collected for children commenced on BVIT from 1st September 2012 to 31st August 2021.

Results: A total of 624 children were commenced on BVIT from 2012 to 2021. 12/624 (1.9%) did not complete the recommended duration of BVIT, the majority of which were due to poor compliance. 33 children (5.2%) developed anaphylaxis. 2/33 children (6.0%) experienced anaphylaxis on multiple occasions, resulting in 36 separate episodes of anaphylaxis. Most of the anaphylactic episodes occurred on Day 1 of BVIT (56%). 23/35 children (65.7%) developed anaphylaxis during the build-up phase and 12/35 children (34.3%) developed anaphylaxis during the maintenance phase. For those who experienced anaphylaxis in the build phase, 6/23 children (26.0%) continued with immunotherapy on the same day, and 5/6 of these children (83.3%) tolerated the same-day continuation of immunotherapy; 17/23 children (73.9%) ceased immunotherapy and restarted on another day, with 11/17 children (64.7%) tolerating cessation and recommencement of the regimen on another day. For those who developed anaphylaxis during the maintenance phase, 6/12 children (50.0%) tolerated ongoing immunotherapy.

Conclusions: Children who experience anaphylaxis during the build-up phase of BVIT showed a low risk of further anaphylaxis with proceeding immunotherapy on the same day. Children who experience anaphylaxis during the maintenance phase of BVIT appear less likely to tolerate ongoing immunotherapy due to the recurrence of anaphylaxis.