A mother of a newborn child suffers from chronic pyelonephritis. She had acute respiratory viral disease before the labor. Labor in time, with prolonged period without waters. A child had erythematous eruption on the 2 day, then there were seropurulent vesicles for about 1cm large. Nikolsky's symptom is positive. Erosions have occured after vesicle rupture. The child is flabby. The temperature is subfebrile. What is the most probable diagnosis?