Glucocorticoids and Rates of Biphasic Reactions in Patients with Adrenaline-Treated Anaphylaxis: A Propensity Score Matching Analysis.

Background: The effectiveness of glucocorticoids in preventing biphasic reactions in patients with anaphylaxis remains controversial.

Objective: We evaluated the effects of glucocorticoids on rates of biphasic reactions in hospitalized patients with anaphylaxis treated with adrenaline.

Methods: In this retrospective observational study using a national inpatient database in Japan, we identified 31,570 hospitalized patients with anaphylaxis treated with adrenaline on the day of admission. We divided them into two groups: those who were treated with adrenaline plus glucocorticoids and those who received adrenaline only on the day of admission. The primary outcome was the occurrence of a biphasic reaction, defined as requiring two or more ampules of adrenaline within 7 days of admission. We performed a one-to-four propensity score matching analysis to compare the outcomes between the two groups.

Results: Of the 31,570 eligible patients, 28,145 (89.2%) were treated with glucocorticoids on the day of admission. The overall percentage of biphasic reactions within 7 days of admission was 11.2%. One-to-four propensity score matching created matched cohorts of 3,425 patients in the control group and 13,700 patients in the glucocorticoid group. After propensity score matching, there were no significant differences in rates of biphasic reactions (10.7% in the glucocorticoids group vs. 10.5% in the control group; odds ratio, 1.03; 95% confidence interval, 0.85-1.24; p = 0.77) between patients with anaphylaxis treated with and without glucocorticoids on the day of admission.

Conclusion: Our findings do not support the use of glucocorticoids to prevent biphasic reactions in hospitalized patients with severe anaphylaxis requiring adrenaline.