DIFFUSE INTRAEPIDERMAL DEPOSITION OF IMMUNOREACTANTS ON DIRECT IMMUNOFLUORESCENCE: A CLUE TO THE EARLY DIAGNOSIS OF EPIDERMAL NECROLYSIS

Background. Toxic epidermal necrolysis is a distinctive disorder that is readily identified clinically and histologically in advanced cases. Early on, however, toxic epidermal necrolysis may be difficult to identify. Some consider fixed drug eruption a limited form of toxic epidermal necrolysis. Methods. Direct immunofluorescence was performed on biopsy material of erythematous skin lesions. Results. Diffuse deposition of immunoreactants in the midmalpighian layer was noted. This finding has not been encountered in other disorders studied in our immuno‐pathology laboratory. Conclusions. Diffuse immunoreactant deposition in the mid‐epidermis should suggest a diagnosis of epidermal necrolysis either from toxic epidermal necrolysis or fixed drug eruption. Additional cases will need to be assessed to document the usefulness of this pattern for prospective diagnosis.