Mother of a newborn suffers from chronic pyelonephritis; she had a case of URTI before the delivery. The delivery is at term, for a long period waters were not breaking. On the 2nd day of life the child developed an erythematic rash, later the rash developed into blisters approximately 1 cm in diameter filled with serous purulent substance. Nikolsky's symptom is positive. After the blisters had been lanced, erosions developed in their place. The child is inert. The child's body temperature is subfebrile. What diagnosis is most likely?