Evaluation of Pediatric and Adult Systemic Reactions to Subcutaneous Immunotherapy (SCIT): Interim Analysis of a Retrospective Chart Review

Abstract

RATIONALE: Current SCIT regimens have wide variability in practice styles and dosing strategies. Most medications require pediatric clinical studies to determine appropriate doses for children. No similar guidelines exist for SCIT. The objective of this study was to describe factors influencing systemic reactions in our study population and to provide preliminary descriptive statistics. METHODS: We conducted a retrospective chart review to record the number of systemic reactions (SR) to SCIT. We used a generalized linear mixed model to examine variables of interest. Crude incidence rate was estimated as number of SRs relative to total injections administered. RESULTS: Of 120 pediatric and 150 adult subjects, there was a significantly higher proportion of males (63% vs 40%; p<0.0001) and subjects with asthma (62.5% vs 46%; p<0.0072) in the pediatric group than the adult group. There was no difference in asthma classification between age groups (intermittent: 29.33% vs 39.13%; p<0.2241; persistent: 70.67% vs 60.87%; p<0.2241). Of 132 reactions, 75 SRs occurred in the pediatric group; 57 SRs occurred in the adult group. The majority of reactions were grades 1 or 2 (83.3%) and more likely to occur in the pediatric group. Reactions occurred more in spring and autumn (35 each) than summer and winter (31 each). Incidence rate (crude) for any SR was 0.2%. CONCLUSIONS: Our results suggest that current allergen SCIT practices are associated with a higher rate of SRs in children. These results provide a foundation for future studies to evaluate factors that may influence practice guidelines for the safe administration of SCIT in children.