Dexamethasone Dosing for Pediatric Croup
Administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) orally, intramuscularly, or intravenously for any pediatric patient with croup. 1
Dosing Recommendations
The standard dose is 0.6 mg/kg with a maximum cap of 16 mg, regardless of route of administration. 1 This recommendation comes from the American Academy of Pediatrics and represents the most widely endorsed approach. 1
Route Selection
- Oral administration is preferred when the child can tolerate it, as it is equally effective as intramuscular or intravenous routes and avoids injection pain. 1
- All three routes (oral, IM, IV) demonstrate equal efficacy for croup treatment. 1
- For children who cannot tolerate oral medication due to vomiting or severe distress, use IM or IV routes. 1
Lower Dose Evidence
While research demonstrates that lower doses (0.15 mg/kg) may be equally effective 2, 3, 4, the guideline-recommended dose remains 0.6 mg/kg to ensure consistent therapeutic effect across all severity levels. 1 The 0.15 mg/kg dose shows benefit as early as 30 minutes 2 and performs similarly to higher doses in hospitalized children 3, 4, but the higher dose provides a safety margin and is the established standard of care.
Treatment Duration
Dexamethasone for croup is given as a single dose only—no tapering or repeat dosing is required for routine cases. 1 The clinical duration of action is approximately 24-72 hours, with onset as early as 30 minutes after administration. 1
When to Consider Repeat Dosing
For severe croup with prominent stridor, significant retractions, and agitation, administer a repeat dexamethasone dose plus nebulized epinephrine regardless of timing of the initial dose. 1 This represents the only scenario where repeat dosing is indicated.
Adjunctive Therapy for Moderate to Severe Cases
For moderate to severe croup with significant respiratory distress, add nebulized epinephrine (0.5 mL/kg of 1:1000 solution, maximum 5 mL) while waiting for dexamethasone to take effect. 1, 5 Dexamethasone provides longer-lasting relief while epinephrine provides immediate but short-term symptom improvement. 1
- If racemic epinephrine is unavailable, L-epinephrine (1:1000) can be substituted at 0.5 mL/kg up to 5 mL. 5
- Children requiring two epinephrine treatments should be hospitalized. 6
Critical Age Consideration
Infants under 2 months with croup symptoms require immediate hospital referral due to significantly higher mortality risk. 7 These infants need comprehensive evaluation for alternative diagnoses including bacterial tracheitis, pertussis, sepsis, or congenital airway abnormalities. 7
Common Pitfalls to Avoid
- Do not use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup. 1
- Do not use prednisolone as a substitute for dexamethasone—it results in significantly higher re-presentation rates (29% vs 7%). 8
- The single-dose regimen does not cause significant adrenal suppression and requires no tapering. 1
- Dexamethasone provides no benefit for pertussis-associated cough or non-specific cough. 1