• Porphyria cutanea tarda;
  • venesection;
  • ferritin;
  • porphyrins


We have examined prospectively the plasma ferritin levels during management often patients with porphyria cutanea tarda (PCT) who were being treated by venesection. We compared plasma ferritin levels with clinical features as well as with plasma, urine and faecal porphyrin levels.

Plasma ferritin and porphyrin levels were found to be variable during the initial period of treatment, and then decreased in parallel with the clinical improvement. Clinical remission and a fall in porphyrin levels lagged several weeks behind the near exhaustion of body iron stores as indicated by plasma ferritin levels. This lag period and the initial variable porphyrin levels are best explained, we believe, by the presence of a large accumulation of porphryin in the liver of patients with PCT. We suggest that venesection be stopped when plasma ferritin falls to the lower end of the reference range.