AAAAI/ACAAI Subcutaneous Immunotherapy Surveillance Study (2013-2017): Fatalities, Infections, Delayed Reactions, and...

Subcutaneous allergen immunotherapy (SCIT) is highly effective but safety risks exist.

The aims of this study were to: (1) identify clinical practices that could influence fatal and nonfatal systemic allergic reactions (SRs) to SCIT, and (2) identify SCIT-associated infections.

From 2008 to 2016, 27% to 51% of American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology members completed an annual survey of SCIT-related SRs of varying severity. Injection-related local cutaneous and systemic infections were queried for 2014-2016. For 2014-2016, respondents were queried about timing of onset of SRs, postinjection waiting times, and prescription/use of epinephrine autoinjectors.

Data were gathered on 54.4 million injection visits (2008-2016). Two confirmed fatalities from SCIT occurred between 2008 and 2014. An additional 5 confirmed fatalities occurred between 2015 and 2017. No infections occurred in 17.3 million injection visits (2014-2016). Among practices monitoring patients for at least 30 minutes, 15% of SRs occurred after 30 minutes. Practices prescribing an epinephrine autoinjector >90% of the time (29% of practices) did not experience lower rates of delayed grade 3/4 SRs. Of patients experiencing grade 3/4 delayed SRs, 26% and 8% used prescribed self-injectable epinephrine devices during 2014-2015 and 2015-2016, respectively.

There is an unexplained slight increase in SCIT-related fatalities for 2015-2017, although mean annual reported events over 9 years (0.8 fatal reactions per year) have declined. SCIT-related infections were not identified during 2 years of surveillance. The 15% incidence of delayed-onset SRs (>30 minutes) is similar to a prior annual survey. Prescribing epinephrine autoinjectors for SCIT does not appear to improve outcomes, possibly due to low rates of self-administration.