What is the recommended dexamethasone (corticosteroid) dosing for a pediatric patient with croup?

Dexamethasone Dosing for Pediatric Croup

Administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) orally, intramuscularly, or intravenously for any child presenting with croup. 1, 2

Standard Dosing Protocol

• The American Academy of Pediatrics recommends 0.6 mg/kg as the standard dose (maximum 16 mg), administered as a single dose via oral, IM, or IV route. 1, 2
• For a typical 2-year-old weighing 12-13 kg, this translates to approximately 7-8 mg of dexamethasone. 2
• For a child weighing 38 kg, the calculated dose would be 22.8 mg, but it is capped at the maximum of 16 mg (4 mL volume). 1

Route of Administration

• Oral administration is preferred when the child can tolerate it, as it is equally effective as IM or IV injection and avoids the pain of injection. 1, 2
• All three routes (oral, IM, IV) demonstrate equivalent efficacy for croup treatment. 1, 2

Onset and Duration of Action

• Onset of action occurs as early as 30 minutes after administration. 1, 2, 3
• Duration of action is approximately 24-72 hours, providing sustained relief. 1, 2
• No tapering is required for the single-dose regimen, and it does not cause significant adrenal suppression. 1, 2

Lower Dose Considerations

While research has demonstrated that 0.15 mg/kg may be as effective as 0.6 mg/kg for mild to moderate croup 4, 3, 5, the guideline-recommended dose remains 0.6 mg/kg because it provides consistent efficacy across all severity levels without significant adverse effects. 1, 2, 6 The higher dose is particularly important when severity is difficult to assess or when you want to ensure adequate treatment effect.

Adjunctive Therapy for Moderate to Severe Croup

• For children with significant respiratory distress, prominent stridor, or marked retractions, add nebulized epinephrine while waiting for dexamethasone to take effect. 1, 2, 7
• Nebulized epinephrine dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) administered by nebulizer. 1, 2, 7
• If racemic epinephrine is unavailable, L-epinephrine (1:1000) can be substituted at the same dosage. 7
• Epinephrine provides immediate but short-term symptom improvement (lasting minutes to 1-2 hours), while dexamethasone provides longer-lasting relief. 1, 2

Repeat Dosing for Severe Cases

• For patients with severe croup (prominent stridor, significant retractions, agitation), administer a repeat dexamethasone dose plus nebulized epinephrine, regardless of the timing of the initial dose. 1

Important Clinical Caveats

• Dexamethasone is specifically indicated for croup (laryngotracheobronchitis), characterized by the classic "seal-like barking cough." 2
• Do not use dexamethasone for non-specific cough, chronic cough, or pertussis-associated cough, as it provides no benefit in these conditions. 8, 1
• Do not use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup. 1
• Nebulized budesonide is equally effective as oral dexamethasone, but oral administration is simpler and more practical in most settings. 1

Comparison with Prednisolone

• Prednisolone is less effective than dexamethasone for croup. A randomized trial showed that prednisolone 1 mg/kg resulted in 29% re-presentation to medical care compared to only 7% with dexamethasone 0.15 mg/kg. 9
• Stick with dexamethasone as the corticosteroid of choice for croup. 9