Systemic Reactions to Aeroallergen Immunotherapy: A Retrospective Review of Our Practice

Rationale: Aeroallergen Immunotherapy (AIT) is a proven and effective treatment for patients with allergic disease.  Unfortunately, it is not without risks.  The rate of systemic reactions (SR) has been estimated to be approximately 0.1% of injection visits in 2-5% of patients.  We have noticed an increased frequency of SR in our clinic over the past several years and hypothesize that our rate of reactions is higher than current estimates.

Methods: Eighteen patients fit inclusion criteria of having a systemic reaction to AIT between 11/1/12 and 10/31/14.  Controls (n=48) were gathered from two immunotherapy appointment slots directly before and after patients with a systemic reaction. 

Results: The number of systemic reactions per visit at our institution over the study period was 0.002%.  Sixty six percent of patients had a grade 2 systemic reaction.  Patients with systemic reactions were more likely to have had a previous systemic reaction (p = 0.0012, OR 8.6, CI 2.32-31.81) or large local reaction (p = 0.02, OR 5.5, CI 1.33-22.69) compared to the control population.

Conclusions: In our program, the major risks for a systemic reaction to immunotherapy were a prior systemic or large local reaction.  Systemic reactions occurred less frequently in our program than what is reported in the literature.  As part of a quality improvement initiative we demonstrated the overall safety of our immunotherapy program.