[Porphyria cutanea tarda].

Porphyria cutanea tarda (PCT) is caused by decreased activity of uroporphyrinogen decarboxylase (UROD) due to various susceptibility factors, here among pathogenic variants in UROD and the presence of iron overload. Porphyrins are sensitive to light and cause cutaneous symptoms in the form of blisters and ulcers on sun-exposed skin. This review gives an update on diagnosing, monitoring and the treatment of PCT. PCT is often effectively treated with venesection or/and low-dose hydroxychloroquine. Additionally, patients must be informed about sufficient sun protection and reduction of susceptibility factors.