Prednisolone Dosing for Croup
For croup in children, use a single oral dose of dexamethasone 0.6 mg/kg (maximum 16 mg) rather than prednisolone, as dexamethasone is superior in reducing unscheduled medical re-presentations and is the recommended first-line corticosteroid. 1
Why Dexamethasone Over Prednisolone
The American Academy of Pediatrics recommends dexamethasone as the corticosteroid of choice for croup, administered as a single dose of 0.6 mg/kg (maximum 16 mg) via oral, intramuscular, or intravenous routes. 1 This recommendation is based on direct comparative evidence showing prednisolone's inferiority:
A randomized controlled trial demonstrated that prednisolone 1 mg/kg resulted in 29% of children re-presenting to medical care compared to only 7% with dexamethasone 0.15 mg/kg - a clinically significant 22% difference that fell outside the equivalence range. 2
Dexamethasone provides a longer duration of action (24-72 hours) compared to prednisolone's shorter half-life, with clinical effects beginning as early as 30 minutes after administration. 1
The single-dose regimen eliminates compliance issues and does not require tapering or cause significant adrenal suppression. 1
If Prednisolone Must Be Used
If dexamethasone is unavailable and prednisolone must be used, the evidence-based dosing is:
- Prednisolone 1 mg/kg as a single oral dose for mild to moderate croup 2, 3
- Prednisolone 2 mg/kg/day for 3 days was studied in community settings but showed no advantage over single-dose dexamethasone 4
- For severe croup requiring intubation, prednisolone 1 mg/kg every 12 hours decreases intubation duration 5
However, recognize that even when matched for glucocorticoid potency (prednisolone 1 mg/kg versus dexamethasone 0.15 mg/kg), prednisolone performs worse in preventing return visits. 2
Treatment Algorithm for Croup
Mild to Moderate Croup:
- Administer dexamethasone 0.6 mg/kg (maximum 16 mg) orally as first-line therapy 1
- Lower doses of dexamethasone (0.15 mg/kg) appear equally effective to 0.6 mg/kg, though 0.6 mg/kg remains the standard recommendation 3
Moderate to Severe Croup (stridor at rest or respiratory distress):
- Give dexamethasone 0.6 mg/kg plus nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) 6, 7
- Observe for at least 2 hours after the last epinephrine dose to assess for rebound symptoms 7
- Epinephrine effects last only 1-2 hours, while dexamethasone provides sustained relief 7
Hospitalization Criteria:
- Consider admission after three doses of nebulized epinephrine are required 7
- Oxygen saturation <92-94%, age <18 months, or respiratory rate >70 breaths/min warrant admission 7
Critical Pitfalls to Avoid
- Do not use nebulized epinephrine in children about to be discharged, as rebound symptoms may occur after the short-lived effect wears off 7
- Do not rely on humidified or cold air therapy - current evidence shows no benefit for respiratory symptoms 7
- Avoid radiographic studies unless concerned about alternative diagnoses like bacterial tracheitis or foreign body aspiration 7
- Never perform blind finger sweeps in suspected foreign body cases, as this may push objects deeper 7
Why This Matters
The choice between dexamethasone and prednisolone directly impacts patient outcomes. The 22% difference in re-presentation rates translates to one additional unscheduled medical visit prevented for every 4-5 children treated with dexamethasone instead of prednisolone. 2 Given that croup affects thousands of children annually, this represents substantial morbidity reduction and healthcare resource utilization improvement.