Treatment of the porphyrias.

There are seven porphyrias which are caused by defective functions of the enzymes in the haem biosynthesis. Pathogenic mechanisms and symptoms differ greatly in individual porphyrias and, consequently, most of them require a specific therapy. Clinically, the three most important entities are acute porphyric attack, porphyria cutanea tarda and protoporphyria. For an acute porphyric attack the treatment of choice is administration of haem; the other measures are elimination of precipitating factors and symptomatic therapy for many associated symptoms. Porphyria cutanea tarda is controlled by removal of iron by phlebotomies or with low-dose chloroquine. Skin symptoms in protoporphyria can be alleviated with betacaroten but there is no effective procedure to normalize disturbed porphyrin metabolism; hepatic failure seen in some patients may need a liver transplantation. The only effective treatment in congenital erythropoietic porphyria is probably a bone marrow transplantation. No satisfactory treatment is available for very rare delta-aminolevulinic acid dehydrase deficiency porphyria.