Hepatic porphyrias with cutaneous symptoms Cutaneous symptoms of porphyrias are initiated from a phototoxic reaction caused by sunlight and circulating porphyrins in the vascular walls of the skin. This leads in fragility, blistering and scarring of the skin on light-exposed areas. There are approximately 200 patients having hepatic porphyrias with cutaneous symptoms in Finland. Cutaneous symptoms of variegate porphyria and porphyria cutanea tarda are indistinguishable, but an effective treatment is available only for the latter. Differential diagnosis is important due to acute episodes occurring in variegate porphyria.