Tight skin and dysmorphic features in a newborn.

A 5-month-old girl presented with generalized bullae (Figure 1). For 2 months she had experienced intermittent, localized, painful bullae in her diaper area. The bullae had initially been treated with topical mupirocin ointment, followed by a course of systemic antibiotics for presumed staphylococcal scalded skin syndrome. Several days before presentation, the patient was admitted to her local hospital for pain control and intravenous antibiotic therapy because of her poor response to oral antibiotics. During this hospitalization, she became more irritable and developed generalized bullae. A punch biopsy specimen was obtained (Figure 2 and Figure 3). What is your diagnosis?