Low-dose (0.15 mg/kg) versus high-dose (0.6 mg/kg) dexamethasone for pediatric croup: a meta-analysis with trial sequential analysis of RCTs.

INTRODUCTION: Systemic glucocorticoids are the standard treatment for croup. Although dexamethasone 0.6 mg/kg is widely recommended, lower doses may provide similar benefit. To compare oral dexamethasone low dose (0.15 mg/kg) to high dose (0.6 mg/kg) in children with croup. METHODS: We systematically searched PubMed, Embase, and Cochrane Library from inception to November 25, 2025. We restricted our analysis to randomized controlled trials (RCTs) directly comparing low-dose vs high-dose oral dexamethasone in children with croup. Risk ratios (RRs) were calculated for binary outcomes and mean differences (MDs) for continuous outcomes, with 95% confidence intervals (CIs). We performed a random-effect meta-analysis for all outcomes using R software (version 2025.09.2+418). RESULTS: Five RCTs were included, encompassing 1,058 patients, of whom 50% received low-dose dexamethasone and 50% received standard dose. We found no significant difference between doses for croup severity scores at 1hr, 3hr and 4hr (MD -0.05 points; 95% CI -0.37 to 0.27), (MD 0.00 points; 95% CI -0.42 to 0.42) and (MD -0.03 points; 95% CI -0.19 to 0.12) respectively, hospital admission (RR 1.06; 95% CI 0.58 to 1.94), return to healthcare (RR 1.05; 95% CI 0.67 to 1.64), and need for additional racemic epinephrine (RE) (RR 1.58; 95% CI 0.77 to 3.25). DISCUSSION: In this meta-analysis, low-dose oral dexamethasone (0.15 mg/kg) was comparable to the traditional 0.6 mg/kg dose in children with mild to moderate croup, with similar clinical outcomes in croup severity scores at 4 hours, hospital admission, return to healthcare, and need for additional RE. However, trial sequential analysis suggests that the current evidence remains underpowered and inconclusive, as the required information size was not reached for key outcomes. The small number of available RCTs limited statistical power to detect modest differences in effect size. Although we sought to evaluate dose equivalence in children with more severe croup (baseline croup score >5), only three trials included this population, and outcome reporting was insufficiently standardized to allow a meaningful subgroup synthesis. These findings should not be extrapolated to children with severe croup, and adequately powered randomized trials are needed before definitive dosing recommendations can be made. SYSTEMATIC REVIEW REGISTRATION: identifier CRD420251238877.