Randomized controlled trial of intravenous dexamethasone to prevent relapse in the treatment of migraine in a pediatric emergency department

OBJECTIVE: This study aimed to evaluate whether a single dose of intravenous dexamethasone, when added to standard abortive therapy, reduces relapse of migraine after emergency department (ED) discharge in children and adolescents. BACKGROUND: Migraine is a leading cause of headache presentations to the ED for children and adolescents. Although corticosteroids have been suggested to reduce relapse in adults with acute migraine, their efficacy in children remains unknown. METHODS: We conducted a randomized, double blind, placebo-controlled trial at the tertiary pediatric ED of the CHU Sainte-Justine in Montréal, Canada. Patients 8-17 years old with acute migraine attack requiring intravenous rescue therapy (metoclopramide with diphenhydramine) were randomized to receive dexamethasone (0.6 mg/kg iv, max 15 mg) or placebo before discharge. All participants were discharged on oral naproxen for 48 h. The primary outcome was relapse within 48 h, defined as recurrence or worsening of headache after initial improvement. Secondary outcomes included pain scores, return to school and activities, health care revisits, and adverse events. Analyses were performed using a modified intention-to-treat approach including all children who provided data for the primary outcome. RESULTS: Between July 2013 and February 2025, 116 patients were enrolled, and 87 patients (75%) provided outcome data at 48 h. Median age was 14 years, and 85 patients (73%) were female. Relapse occurred in 39% (16 of 41) of the dexamethasone group versus 44% (20 of 46) of the placebo group (risk difference: -4%; 95% confidence interval, -32% to 24%). Pain scores, return to school, functional recovery, and health care consultations did not differ significantly between groups. Adverse events were infrequent and mild in both arms. CONCLUSIONS: In this small clinical trial of children and adolescents with acute migraine attack treated in the ED, adjunctive dexamethasone did not reduce relapse rates nor improve functional outcomes compared with placebo. Although limited by low statistical power, these findings raise questions about the routine use of dexamethasone in migraine management of children and adolescents.