Transient intraepidermal bullous reaction after skin graft for toxic epidermal necrolysis. Ultrastructural and immunohistochemical features similar to those of inherited epidermolysis bullosa simplex.

Blister formation in skin graft donor or recipient sites is uncommon. We describe a 49-year-old female patient with bullae in sites of grafts used in the treatment of toxic epidermal necrolysis. Generalized loss of skin developed 3 weeks after she had ingested phenobarbital. Sixty days after the beginning of the toxic epidermal necrolysis, the reepidermization was only 80% and skin grafts were placed on lower-extremity and abdominal wounds using the first healed sites as donor sites. Several bullae and erosions were noted on grafted areas 3 weeks later. Skin biopsy specimens revealed separation at the dermoepidermal junction, and no autoantibodies were detected by direct and indirect immunofluorescence. Electron microscopy demonstrated that the blister was formed through the basal keratinocytes and that the dermoepidermal junction, including hemidesmosomes and anchoring fibrils, was normal. Immunofluorescence mapping was performed using polyclonal antibodies from the serum of patients with bullous pemphigold and epidermolysis bullosa acquisita and monoclonal antibodies against GB3 antigen and collagen type VII. All but the bullous pemphigold serum gave positive results; only faint and focal staining of the dermoepidermal junction was observed with bullous pemphigold serum. These findings are the same as those encountered in hereditary epidermolysis bullosa simplex. A biopsy performed 1 year later in the same site as the first one revealed that bullous pemphigold antigen was normally expressed. Keratinocytes autografted in the treatment of toxic epidermal necrolysis may become transiently, functionally abnormal because of the alteration of recipient sites.