Single-Dose Dexamethasone is Superior to 3-Day Prednisone for Croup
A single dose of oral dexamethasone (0.6 mg/kg, maximum 10-12 mg) is the preferred treatment for croup and should be used instead of a 3-day course of prednisolone. 1, 2
Evidence Supporting Single-Dose Dexamethasone
The most compelling evidence comes from a randomized controlled trial directly comparing these regimens in children with croup. Children treated with a single dose of dexamethasone (0.6 mg/kg) had significantly fewer unscheduled returns to medical care (7%) compared to those receiving 3 days of prednisolone (29%) - a clinically meaningful 22% absolute difference. 2
This finding was corroborated by a community-based trial showing no differences in clinical outcomes between the two treatments, but importantly demonstrating that the multi-day prednisolone course offered no additional benefit over single-dose dexamethasone for:
- Duration of croup symptoms (2.8 vs 2.2 days) 1
- Additional healthcare visits (2% vs 7%) 1
- Parental sleep disruption 1
Why Dexamethasone is Preferred
Dexamethasone has a longer half-life (36-72 hours) compared to prednisolone (12-36 hours), allowing for single-dose administration while maintaining therapeutic effect. 3, 4
The practical advantages include:
- Eliminates compliance issues associated with multi-day dosing 4
- Single administration ensures complete treatment - no risk of parents discontinuing therapy early 5
- Easier to administer in the acute setting 5
- Lower cost due to single dose 5
Dosing Recommendations
Administer oral dexamethasone 0.6 mg/kg (maximum 10-12 mg) as a single dose. 5, 6
- For children who cannot tolerate oral medication due to vomiting or severe respiratory distress, intramuscular dexamethasone at the same dose is equally effective 6
- Oral and intramuscular routes show no significant differences in need for subsequent interventions (8% for both routes) 6
Clinical Outcomes
Single-dose dexamethasone has been shown to:
- Reduce hospitalizations compared to placebo 5
- Shorten length of illness 5
- Decrease need for subsequent treatments 5
- Result in rare complications with excellent tolerability 5
Common Pitfall to Avoid
Do not use prednisolone for croup simply because it is available in liquid formulation. While prednisolone has this practical advantage, the clinical evidence clearly demonstrates inferior outcomes with higher re-presentation rates. 2 The convenience of liquid preparation does not outweigh the superior efficacy and compliance advantages of single-dose dexamethasone.