Q. A 10-day-old boy is brought to the physician’s office by his mother for a facial skin rash that has been present for the past 3 days. She says that the baby is not scratching and he is otherwise well with no other symptoms. His birth history shows that he is a full-term baby born to a healthy 28-year-old primigravid mother with a birth weight of 2.75kg and normal APGAR scores. He is the outcome of normal vaginal delivery. His temperature is 98.6°F (37°C), pulse is 110/min, blood pressure is 70/40 mmHg, and respirations are 40/min. Physical examination shows multiple, superficial, clear vesicles of size 1 to 2mm. They are widely spread on the face, neck, and upper trunk. They resemble small water droplets and there is no associated erythema. The rest of the examination is unremarkable. What is the most likely diagnosis for this baby based on his clinical features?