Real-World Adrenaline Auto-Injector Use During Pediatric Anaphylaxis in Japan: A Single-Center Descriptive Study

Although adrenaline auto-injector (AAI) prescribing has increased in Japan following insurance coverage expansion, real-world utilization during pediatric anaphylaxis remains insufficiently characterized. This study aimed to describe current AAI prescription patterns, actual utilization rates, and factors potentially associated with appropriate use.

This retrospective descriptive study analyzed AAI prescriptions and anaphylaxis hospitalizations at a tertiary care hospital in Shizuoka, Japan (2023-2024). We reviewed 124 AAI-prescribed children and 34 hospitalized anaphylaxis cases. For hospitalized patients possessing AAI (n = 8), we conducted detailed interviews assessing prior education quality, including hands-on training with expired AAI and smartphone application utilization.

Among 124 AAI-prescribed patients, only 5 (4.0%) used AAI during follow-up. Among 34 hospitalized anaphylaxis cases, more than half (55.9%) occurred on first known allergen exposure, particularly for seafood (92.9%). Only 8 patients (23.5%) possessed an AAI prior to the event; among them, 4 (50%) used their AAI. Notably, AAI use appeared to differ by concordance between the triggering allergen and the allergen for which AAI was prescribed: 4/5 (80%) used AAI when allergens matched versus 0/3 (0%) when they differed.

This study characterized current AAI prescription patterns and real-world utilization during pediatric anaphylaxis in Japan. Only 23.5% of hospitalized anaphylaxis cases possessed AAI, and utilization among possessors differed markedly depending on whether the triggering allergen matched the prescription indication. These findings suggest that AAI education should emphasize use for any anaphylaxis symptoms regardless of trigger.