Bullous systemic lupus erythematosus.

Blistering eruptions are rare cutaneous manifestations of lupus erythematosus (LE) that may be caused by different mechanisms. Subepidermal clefting with frank vesiculation may occur in early lesions of chronic-, subacute-, and acute-cutaneous LE due to a severe vacuolar alteration of the dermoepidermal junction (DEJ), dermal edema, and lekocytoclastic vasculitis. An exaggerated example of such changes is rarely seen at the advancing edge of the annular plaques of subacute cutaneous LE with erythema-multiforme (EM)-like appearance, a condition formerly described as Rowell's syndrome. In a recently reported novel variant of LE-associated toxic epidermal necrolysis, dysregulated keratinocyte apoptosis has been proposed as an underlying mechanism. These vesiculobullous lesions are considered to be LE-specific. Blistering may also occur in LE in the context of a coexisting immunobullous disease. Pemphigus, bullous pemphigoid (BP), epidermolysis bullosa acquisita (EBA), dermatitis herpetiformis, and linear IgA bullous dermatosis have been all reported in association with LE. Their differentiation relies upon characteristic clinical, histologic, and immunopathologic features (Table 1). These blistering eruptions are rather non-specific for LE.