Porphyria cutanea tarda in pre-existent lupus erythematosus--is there an association?

In lupus erythematosus (LE), vesicles and bullae are only rarely seen. However, in some instances such efflorescences might suggest an association with distinct cutaneous diseases, including erythema multiforme, toxic epidermal necrolysis or autoimmune blistering disorders such as bullous pemphigoid, pemphigus vulgaris, and dermatitis herpetiformis Duhring. Another blistering disease that has been described in association with cutaneous and systemic LE is porphyria cutanea tarda (PCT). PCT is a metabolic disorder caused by a deficiency of the fifth enzyme in heme biosynthesis, uroporphyrinogen decarboxylase. Here, we report on a 57-year-old Caucasian woman of Dutch origin with a medical history of mild cutaneous LE who developed skin fragility, blistering skin lesions, milia, and facial hypertrichosis. Subsequent porphyrin analysis in urine and feces confirmed the suspected simultaneous manifestation of LE and PCT.