Swelling Behind the Ear: Seen in the ED

History of present illness: A 2-year-old girl is brought in by parents for 4 days of low-grade fever and 1 day of swelling behind her left ear. She recently recovered from an upper respiratory infection and seemed to be back to normal for a day or two before this started.

Vital signs and physical examination: Vital signs are normal except for a temperature of 99.3°F. Physical examination is also normal except for left sided otitis media and swelling behind the left ear, which is shown below.