Dexamethasone Dosing for Croup in Children
For children aged 6 months to 5 years with croup, administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) via oral, intramuscular, or intravenous route. 1, 2
Standard Dosing Protocol
- Dose: 0.6 mg/kg (maximum 16 mg) as a single administration 1, 2
- Route options: Oral (preferred), intramuscular, or intravenous—all three routes are equally effective 1, 2
- Preferred route: Oral administration when the child can tolerate it, as it avoids injection pain while maintaining equal efficacy 2
- Onset of action: As early as 30 minutes after administration 1, 2
- Duration of effect: 24-72 hours of sustained symptom relief 1, 2
Lower Dose Evidence (Important Caveat)
While the guideline-recommended dose is 0.6 mg/kg, research demonstrates that 0.15 mg/kg is equally effective for both mild-to-moderate and moderate-to-severe croup 3, 4. However, the American Academy of Pediatrics continues to recommend the higher 0.6 mg/kg dose as standard practice 1, 2. The lower dose shows benefit as early as 30 minutes and produces similar hospitalization duration, croup score reduction, and epinephrine requirements 5, 3, 4.
Adjunctive Therapy for Moderate-to-Severe Cases
When to add nebulized epinephrine: For children with prominent stridor, significant retractions, and respiratory distress 6, 2
- Epinephrine dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) via nebulizer 6, 2
- Alternative: If racemic epinephrine unavailable, use L-epinephrine 1:1000 at same dosing 6
- Mechanism: Epinephrine provides immediate but short-term relief while dexamethasone takes effect and provides longer-lasting benefit 1, 2
- Hospitalization criteria: Children requiring two epinephrine treatments should be hospitalized 7
Repeat Dosing for Severe Croup
For severe croup with persistent symptoms: Administer a repeat dose of dexamethasone plus nebulized epinephrine, regardless of timing of the initial dose 1, 2
Critical Clinical Caveats
- No tapering required: Single-dose regimen does not cause significant adrenal suppression and needs no taper 1, 8
- Do NOT use dexamethasone for: Non-specific cough, chronic cough, or pertussis-associated cough—it provides no benefit in these conditions 1
- Prednisolone is inferior: Prednisolone shows 29% re-presentation to medical care compared to 7% with dexamethasone 1
- Avoid nebulized corticosteroids from hand-held inhalers with spacers: These are ineffective for croup 1
Practical Example
For a typical 2-year-old weighing 12-13 kg: the dose would be 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 1.