Dexamethasone Dosing for Croup
Administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) orally, intramuscularly, or intravenously for all children with croup, regardless of severity. 1
Standard Dosing Regimen
The American Academy of Pediatrics recommends 0.6 mg/kg (maximum 16 mg) as the standard dose, which can be given via oral, intramuscular, or intravenous routes with equal efficacy. 1
For a child weighing more than 26.7 kg, the calculated dose would exceed 16 mg, but the maximum dose is capped at 16 mg (4 mL volume). 1
Oral administration is strongly preferred when the child can tolerate it, as it is equally effective as parenteral routes while avoiding injection pain and being more practical and cost-effective. 2, 1
Intravenous administration should be infused slowly over several minutes to prevent perineal burning. 2
Lower Dose Considerations
While the standard 0.6 mg/kg dose is recommended by guidelines, research evidence suggests lower doses may be equally effective:
Dexamethasone 0.15 mg/kg has been shown to be as effective as 0.6 mg/kg in reducing croup scores, duration of hospitalization, and need for additional treatments in multiple randomized controlled trials. 3, 4, 5
The 0.15 mg/kg dose demonstrated equivalent efficacy to 0.6 mg/kg at 2 hours, 6 hours, and 12 hours post-administration, with no differences in epinephrine use, intubation rates, or return visits. 4, 5
However, one study showed that 0.6 mg/kg may provide better symptom reduction at 24 hours compared to 0.15 mg/kg. 5
Despite research supporting lower doses, current guideline recommendations remain at 0.6 mg/kg, which should be followed in standard practice. 1
Timing and Duration of Action
Dexamethasone begins working within 30 minutes of administration, with clinical effects lasting 24-72 hours. 1
A single dose is sufficient and does not require tapering or cause significant adrenal suppression. 1
For intubated patients requiring extubation, administer dexamethasone at least 6 hours before anticipated extubation to prevent upper airway obstruction. 1
Adjunctive Therapy for Moderate-to-Severe Croup
For children with significant respiratory distress (prominent stridor, marked retractions, agitation), add nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) while waiting for dexamethasone to take effect. 2, 1
Epinephrine provides immediate but short-term relief (lasting approximately 2 hours), while dexamethasone provides longer-lasting symptom control. 1
Repeat Dosing
For severe croup with persistent symptoms, administer a repeat dose of dexamethasone plus nebulized epinephrine, regardless of timing of the initial dose. 1
Do not assume repeat dosing is necessary for all children with persistent cough, as dexamethasone provides no benefit for non-croup-related cough. 1
Alternative Corticosteroid Options
Nebulized budesonide (500 µg) may reduce symptoms in the first 2 hours but is less commonly used than oral dexamethasone due to convenience and cost factors. 2
Do not use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup. 1
Prednisolone shows little to no difference compared to dexamethasone at 2 hours, but dexamethasone likely reduces return visits or readmissions by approximately 45% and decreases the need for supplemental glucocorticoids by 28%. 5
Important Clinical Pitfalls
Avoid using antifungal prophylaxis unless the child requires prolonged steroid therapy beyond the single-dose regimen used for croup. 2
Children requiring two epinephrine treatments should be hospitalized for observation. 6
Antihistamines, decongestants, and antibiotics have no proven benefit in uncomplicated viral croup. 6