“Hello, doctor! You asked me to bring Bob back if anything happened. I think he has the flu. He has been coughing and has a runny nose. He also complains of a sore throat and has fever again. Some of his classmates have been showing the same symptoms.”

You smile at the mother-son duo in front of you. Three weeks ago, you diagnosed 4-year-old Bob with Kawasaki disease. You administered a single dose of intravenous immunoglobulin (IVIG) and started him on high-dose aspirin. After being fever-free for 48 hours, you transitioned Bob to low-dose aspirin. After the sixth day of initial treatment, the majority of Bob's symptoms resolved completely. However, echocardiography showed a small coronary artery aneurysm. Despite the small aneurysm, Bob was able to go home. You asked his mother, Mrs. Pearson, to bring him back in six weeks' time—or earlier, if anything untoward happened.

You remember that Bob's medical, surgical, and family histories are all unremarkable. He is not on any other medications. He has no known allergies. Growth and development are normal. All vaccines are up-to-date.