Dexamethasone Dosing for Croup in Children
Administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) orally for pediatric patients with croup, as this is the standard dose recommended by the American Academy of Pediatrics. 1, 2
Standard Dosing Protocol
- The recommended dose is 0.6 mg/kg with a maximum cap of 16 mg, regardless of calculated dose. 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 must be capped at the maximum of 16 mg (4 mL volume). 1
Route of Administration
Oral administration is the preferred route when the child can tolerate it, as it is equally effective as intramuscular or intravenous routes and avoids the pain of injection. 1, 2
- All three routes (oral, IM, IV) demonstrate equal efficacy for croup treatment. 1, 2
- Choose IM or IV only if the child cannot tolerate oral medication due to severe distress or vomiting. 1
Clinical Onset and Duration
- Onset of action occurs as early as 30 minutes after administration, much earlier than previously thought. 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
Evidence Regarding Lower Doses
While research has shown that lower doses (0.15 mg/kg and 0.3 mg/kg) may be equally effective as 0.6 mg/kg 4, 5, 3, the American Academy of Pediatrics continues to recommend 0.6 mg/kg as the standard dose. 1, 2 This higher dose remains the guideline-endorsed approach despite evidence suggesting lower doses work equally well for mild to moderate croup. The 0.6 mg/kg dose provides a margin of safety across all severity levels without increased adverse effects.
Adjunctive Therapy for Moderate to Severe Croup
For children with significant respiratory distress (prominent stridor, significant retractions, agitation), add nebulized epinephrine while waiting for dexamethasone to take effect. 1, 2
- Nebulized epinephrine dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL). 1, 2
- Epinephrine provides immediate but short-term symptom improvement (minutes), while dexamethasone provides longer-lasting relief (hours to days). 1, 2
Repeat Dosing for Severe Cases
For patients with severe croup who remain symptomatic, administer a repeat dose of dexamethasone plus nebulized epinephrine regardless of the timing of the initial dose. 1
Critical Age-Related Caveat
Infants under 2 months with croup symptoms require immediate hospital referral due to significantly higher mortality risk. 6
- These young infants need comprehensive evaluation for alternative diagnoses including bacterial tracheitis, pertussis, or congenital airway abnormalities. 6
- Do not treat at home—transfer immediately to the emergency department. 6
Important Clinical Pitfalls
- Dexamethasone is specifically for croup (laryngotracheobronchitis) with the characteristic "seal-like barking cough"—it provides no benefit for non-specific cough or pertussis-related cough. 1, 2
- 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