What is the first-line treatment for mild to moderate croup in a child with stridor?

• A. Nebulized epinephrine.
• B. Antibiotics.
• C. Dexamethasone.
• D. Saline nasal drops.

Answer: (C)

Croup is an inflammatory process that narrows the airway, so the primary goal is to reduce that edema. A single dose of dexamethasone is the preferred first-line treatment because it directly decreases subglottic swelling, leading to meaningful improvement in stridor and work of breathing within hours, and its effect lasts for about a day. It can be given orally or intramuscularly, typically at around 0.6 mg/kg, which makes it easy to administer in the clinic or ED and often prevents the need for additional interventions.

Nebulized epinephrine is reserved for more severe cases with significant stridor at rest or respiratory distress, since its relief is rapid but short-lived and it requires careful observation afterward. Antibiotics aren’t routinely used unless there’s suspicion of a bacterial complication, and saline nasal drops don’t address the inflammatory airway edema seen in croup.