Practice question

A 2-year-old child presents with a 3-day history of barking cough, hoarseness, and inspiratory stridor, worse at night. On examination, the child is alert, with mild intercostal recession but no cyanosis. Oxygen saturation is 96% on air. Temperature is 37.8°C. What is the most appropriate single dose of medication to administer in primary care or on arrival to hospital for mild to moderate croup?