Q. A 3-year-old male was admitted last night through the emergency department following a 2-week history of fevers and a rash. No source of the infection was identified by the admitting physician. You are called to assist in determining the diagnosis. Upon review of the patient’s chart, it is noted that his immunizations are up to date, there is no history of similar symptoms, recent travel, or known sick contacts. Blood and urine cultures were obtained in the emergency department. A significant amount of white blood cells were seen in his urine, though no bacteria were noted. On physical examination, his temperature is 38.6 degrees Celsius (101.5 degrees Fahrenheit), blood pressure 95/50 mm Hg, heart rate 90/min, respiratory rate 22/min, and oxygen saturation is 99 percent on room air. The patient’s pupils are equal, round, and reactive to light and accommodation. His conjunctiva are injected bilaterally with notable perilimbal sparing, though without detectable matting, discharge, or exudate. The oropharynx is erythematous without tonsillar hypertrophy. His tongue and lips are bright red and swollen. The tympanic membranes are injected, but clear bilaterally. The patient’s lungs are also clear, and his cardiac examination is unremarkable with no murmurs, rubs, or gallops detected. An erythematous polymorphous rash is noted on his trunk and extremities. Perianal erythematous desquamation is also noted without induration. The dorsums of the patient’s hands and feet are noted to be edematous bilaterally. Further inspection demonstrates marked erythema of both the palms and soles of his feet. Laboratory Results: Complete Blood Count Leukocyte Count 13,000 mm3 Hemoglobin 9.2 g/dL Hematocrit 35 percent Platelets 690,000 mm3 Liver Function Tests Alanine aminotransferase 71 U/L Aspartate aminotransferase 80 U/L Total Proteins 10 g/dL Total Bilirubin 0.9 mg/dL Albumin 2.2 g/dL Hematologic Studies C-Reactive Protein 30 mg/L Erythrocyte Sedimentation Rate 40 mm/h Based upon the history, physical examination, and laboratory results, what is the most likely diagnosis?