Cutaneous Porphyrias: Causes, Symptoms, Treatments and the Danish Incidence 1989-2013.

Porphyrias are rare diseases caused by altered haem synthesis leading to the accumulation of different haem intermediates. Neurovisceral attacks may occur in acute porphyrias, while photosensitivity is the presenting symptom in cutaneous porphyrias. We present here an overview of symptoms and a flowchart for the diagnosis of cutaneous porphyrias, with recommendations for monitoring and an update of treatment options. From the Danish Porphyria Register, we present the incidences and approximate prevalences of cutaneous porphyrias within the last 25 years. A total of 650 patients with porphyria cutanea tarda were identified, 73 with erythropoietic protoporphyria, 9 with variegate porphyria, 4 with hereditary coproporphyria and one with congenital erythropoietic porphyria. The total incidence of all porphyrias was ~0.52/100,000 per year.