[Porphyria cutanea tarda: the benefit of additional diagnostics].

The porphyrias are a clinically and genetically heterogeneous group of relatively rare metabolic diseases that result from disorders in the biosynthesis of haeme. Porphyria cutanea tarda (PCT) is the most common type, accounting for 80-90% of all porphyrias, and is essentially an acquired disease, although PCT can also occur on a familial basis. We describe a 71-year-old female and a 62-year-old male patient, both of whom had several risk factors for developing PCT, ranging from iron overload due to a mutation in the hereditary haemochromatosis protein (HFE) gene, alcohol use, smoking, and exogenous oestrogen, to persistent hepatitis C infection. The clinical relevance of the several diagnostic modalities is important in PCT. Diagnostic evaluation is important in order to confirm the diagnosis, but also to evaluate the treatment response in the context of long-term follow-up in the prevention of late complications of PCT, i.e. hepatocellular carcinoma.