Mother of a newborn child suffers from chronoc pyelonephritis. She survived acute respiratory viral infection directly before labour. Delivery was at term, the period before discharge of waters was prolonged. On the 2-nd day the child got erythematous rash, later on - vesicles about 1 cm large with seropurulent content. Nikolsky's symptom is positive. Dissection of vesicles results in erosions. The child is inert, body temperature is subfebrile. What is the most probable diagnosis?