Prednisolone Dosing for Croup
For croup, prednisolone 1 mg/kg as a single oral dose is effective, but dexamethasone 0.15-0.6 mg/kg is superior and should be used preferentially. 1, 2
Primary Recommendation
- Dexamethasone is the preferred corticosteroid for croup treatment, not prednisolone, based on direct comparative evidence showing better outcomes. 2
- The standard dexamethasone dose is 0.6 mg/kg orally (maximum 10-12 mg) for moderate-to-severe croup. 1, 3
- Lower-dose dexamethasone 0.15 mg/kg is equally effective as 0.6 mg/kg and may be appropriate for mild-to-moderate cases. 4
Why Prednisolone is Less Preferred
- In a randomized controlled trial, prednisolone 1 mg/kg resulted in 29% re-presentation rate compared to only 7% with dexamethasone 0.15 mg/kg - a clinically significant 22% difference. 2
- While one study showed no difference between prednisolone 2 mg/kg for 3 days versus single-dose dexamethasone 0.6 mg/kg, this used a multi-day regimen rather than the standard single-dose approach. 5
- Another trial found prednisolone 1 mg/kg equivalent to dexamethasone 0.15-0.6 mg/kg, but the confidence intervals and overall evidence favor dexamethasone. 4
If Prednisolone Must Be Used
When dexamethasone is unavailable, prednisolone 1 mg/kg as a single oral dose is the recommended alternative. 6, 4
- For severe croup requiring intubation, prednisolone 1 mg/kg every 12 hours decreases duration of intubation and need for re-intubation. 6
- The evidence supports single-dose therapy for outpatient management, not multi-day courses. 2, 4
Route of Administration
- Oral route is preferred for all patients who can tolerate it. 3
- Intramuscular dexamethasone is reserved for patients who are vomiting or in severe respiratory distress unable to tolerate oral medication. 3
- Nebulized budesonide 2 mg is an alternative with equivalent efficacy to oral dexamethasone but is less commonly used due to cost and administration complexity. 6, 3
Adjunctive Therapy for Severe Cases
- Nebulized racemic epinephrine 0.05 mL/kg (maximum 0.5 mL) of 2.25% solution or L-epinephrine 0.5 mL/kg (maximum 5 mL) of 1:1000 solution should be used for acute airway edema in severe croup. 1
- Corticosteroids should be administered simultaneously with nebulized epinephrine in severe cases. 1
Critical Caveats
- The single major risk of corticosteroid use in croup is increased severity of varicella infection if exposed, though this risk is minimal with single-dose therapy. 6
- Do not use multi-day prednisolone courses for routine outpatient croup management - single-dose therapy is the standard of care. 2, 4
- Corticosteroids are now considered standard of care for moderate-to-severe croup and reduce hospitalizations, length of illness, and need for subsequent treatments. 3