In a child with acute viral croup, should dexamethasone be used instead of prednisolone?

Dexamethasone Should Be Used Instead of Prednisolone for Croup

For children with acute viral croup, dexamethasone is superior to prednisolone and should be the corticosteroid of choice. A single oral dose of dexamethasone 0.6 mg/kg (maximum 16 mg) is the evidence-based standard of care 1, 2, 3.

Why Dexamethasone Over Prednisolone

Prednisolone results in significantly higher rates of unscheduled return to medical care compared to dexamethasone. In a randomized controlled trial, 29% of children treated with prednisolone re-presented for medical care versus only 7% treated with dexamethasone—a clinically meaningful 22% absolute difference 4. This finding is reinforced by guideline recommendations that explicitly advise against using prednisolone instead of dexamethasone due to this higher re-presentation rate 3.

While one community-based trial found no significant differences between the two agents 5, and another recent study showed both reduced croup scores 6, the weight of evidence—particularly the striking difference in re-presentation rates—favors dexamethasone as the superior choice 4.

Recommended Dosing and Administration

Give a single oral dose of dexamethasone 0.6 mg/kg (maximum 16 mg) 1, 2, 3, 7:

• Oral route is preferred when the child can tolerate it—equally effective as intramuscular or intravenous routes while avoiding injection pain 1, 2
• Onset of action begins within 30 minutes to 2 hours, with clinical effects lasting 24-72 hours 1, 2, 3
• No tapering required and does not cause clinically significant adrenal suppression with single-dose use 1, 2
• Alternative routes (IM or IV) are equally effective if oral administration is not feasible 1, 2

When to Add Nebulized Epinephrine

For moderate to severe croup with significant respiratory distress, prominent stridor, or marked retractions 1, 2, 3:

• Add nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) while waiting for dexamethasone to take effect 1, 2
• Epinephrine provides rapid but short-term relief, while dexamethasone offers longer-lasting benefit 1, 2
• If severe symptoms persist, give a repeat dose of dexamethasone plus additional nebulized epinephrine regardless of timing of initial dose 1, 2

Age Considerations

There is no minimum age cutoff that contraindicates a single dose of dexamethasone for confirmed croup 2:

• Even infants younger than the typical 6-month to 6-year age range may be safely treated 2, 8
• The contraindication for high-dose dexamethasone in preterm neonates for bronchopulmonary dysplasia does NOT apply to term infants with acute croup 2

Critical Diagnostic Confirmation

Confirm croup diagnosis before administering dexamethasone by identifying the characteristic "seal-like barking cough" and inspiratory stridor 2, 8:

• Do not use dexamethasone for non-specific cough, chronic cough, or pertussis-associated cough—it provides no benefit in these conditions 1, 2, 3
• Croup involves subglottic inflammation that responds to steroids; bronchitis involves lower airways and is self-limiting without steroid benefit 3

Common Pitfalls to Avoid

• Avoid prednisolone due to higher re-presentation rates 3, 4
• Do not use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup 1
• Do not withhold steroids based on mild severity—all children presenting with croup symptoms should receive dexamethasone 3, 7
• Do not assume repeat dosing is needed for persistent cough—dexamethasone provides no benefit for non-croup cough 1