A 12-year-old girl became acutely ill with a fever of 38.5°C and a rash appearing on her skin. Objectively, her condition is of moderate severity, she has hepatosplenomegaly, fine puncture rash and maculopapular rash on the flexor surfaces of her limbs, lateral surfaces of the trunk, and lower abdomen. Demarkated bluish-pink coloring is observed on her hands and feet. What is the most likely diagnosis in this case?