Dexamethasone Dosing for Mild Croup in a 20 kg Child
For a 20 kg female with mild croup, administer a single dose of oral dexamethasone 0.6 mg/kg, which equals 12 mg (or 3 mL if using the standard 4 mg/mL concentration). 1, 2
Dose Calculation and Administration
- Standard dose: 0.6 mg/kg × 20 kg = 12 mg as a single oral dose 1, 2, 3
- This dose is within the recommended range of 0.15-0.6 mg/kg (maximum 10-16 mg depending on guideline) 2, 4, 5
- Oral administration is preferred when the child can tolerate it, as it is equally effective as intramuscular or intravenous routes and avoids injection pain 3, 6
Evidence Supporting This Dose for Mild Croup
The evidence strongly supports using corticosteroids for all severities of croup, including mild cases 2, 4, 5. While some research suggests lower doses (0.15 mg/kg) may be equally effective 7, 8, the standard 0.6 mg/kg dose remains the most widely recommended in current guidelines 1, 2, 3.
Key points about dosing:
- A single dose of 0.6 mg/kg provides clinical benefit lasting 24-72 hours with onset as early as 30 minutes 3
- Lower doses (0.15 mg/kg) showed similar efficacy in some studies, but the evidence is less robust 7, 8
- No tapering is required and single-dose administration does not cause significant adrenal suppression 3
What NOT to Do in Mild Croup
- Do not add nebulized epinephrine for mild croup—it is reserved for moderate to severe cases with stridor at rest or respiratory distress 1, 2, 4
- Do not use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup 3
- Do not use humidified or cold air therapy—current evidence shows no benefit 1, 2, 4
- Do not use antibiotics routinely—croup is viral in etiology 2
Observation and Discharge Planning
- For mild croup treated with oral dexamethasone alone, no prolonged observation is required 2
- Provide clear return precautions: return if stridor worsens, respiratory distress develops, or the child cannot maintain adequate oral intake 2
- Symptoms typically improve within 2 hours and resolve within 2 days 4
- If not improving after 48 hours, the child should be reviewed by a physician 1, 2
Common Pitfall to Avoid
The most common error is failing to administer corticosteroids in mild cases 2. The evidence over the last two decades strongly favors corticosteroid use in all croup presentations, regardless of severity, as it reduces hospitalizations, length of illness, and need for subsequent treatments 5, 7.