Subacute cutaneous lupus erythematosus with bullae associated with porphyria cutanea tarda.

A 58-year-old patient presented with both annular and polycyclic as well as vesicular lesions. Histology revealed an interface dermatitis with focal hyperkeratosis and subepidermal blistering. Antinuclear antibodies were elevated (1 : 1280) and autoantibodies against Ro-SS-A were found. Based on these findings we made a diagnosis of subacute cutaneous lupus erythematosus (SCLE) with blister formation. Additionally, we diagnosed porphyria cutanea tarda (PCT) triggered by alcohol abuse. Treatment with systemic corticosteroids and low-dose hydroxy-chloroquine led to rapid resolution of the skin changes. SCLE with blister formation is a rare cause of bullous skin eruptions and has to be distinguished from bullous autoimmune diseases as well as from bullous SLE. Recognition of concomitant PCT, which may be associated with all forms of LE, is especially important because of the therapeutic implications, since a reduced dosage of antimalarials is required.