Croup

A previously healthy 2-year-old girl has the onset of crouplike symptoms at 11 p.m. She is seen in an emergency department 2 hours later with a barking cough and, when upset, inspiratory stridor. Her temperature is 36.1°C, respiratory rate 20 breaths per minute, heart rate 151 beats per minute, and oxygen saturation 94% while breathing ambient air.