Clinical History.—This 4-year-old girl came to the emergency room at 6:30 am complaining of coughing, sore throat, and difficulty in breathing, which had commenced at 2 am. She had vomited twice. There was no history of allergy, asthma, or previous episodes of sore throat. The family history was noncontributory.
Physical Examination.—The temperature was 39.1 C, pulse rate was 156 beats per minute, and respiratory rate was 36/min. She was a well-developed, well-nourished girl who was slightly dusky in color and in severe dyspnea with stridor. The eyes and ears were normal. The mouth was examined with difficulty, but no obstruction was identified. The neck was supple. Deep retractions of the chest were noted and bilateral rales heard. The remainder of the examination was within normal limits. The hemoglobin value was 10.7 gm/100 ml; the white blood cell count was 21,400/cu mm, with 87% segmented cells, 7% lymphocytes,