[Porphyria cutanea tarda]

Therapy of porphyria cutanea tarda

Porphyria cutanea tarda (PCT) is the most common type of porphyria. There is an association of PCT with haemochromatosis, diabetes mellitus and hepatitis C infection. The basis of treatment of PCT consists of three elements: avoidance of triggering factors, iron depletion and porphyrin elimination. Alcohol and certain systemic medical drugs, such as oestrogens (or tuberculostatics), should be considered as triggering factors, and as far as possible, avoided. Other triggering factors, such as chronic haemodialysis in renal insufficiency, need a different approach. The hallmark in iron depletion is phlebotomy. Porphyrin elimination is achieved using low-dose chloroquin therapy. The treatment is safe and effective but has its limits in cases with haemochromatosis (HFE) gene mutations. Here iron depletion needs additional phlebotomy. In patients with chronic haemodialysis-associated PCT, chloroquine is ineffective. Erythropoietin, desferroxamine and small-volume phlebotomy have been employed to control the disease. Childhood PCT is very rare. No controlled studies are available, but published experience suggests that body weight-adapted chloroquine therapy or small volume phlebotomy might be useful.

Hochdosierte Vitamingabe zur Verhinderung einer Porphyria cutanea urämica?

50 Patients with chronic renal failure undergoing hemodialysis with or without porphyria cutanea tarda (PCT)-like skin changes were investigated. The total porphyrin amount in erythrocytes, plasma and dialysate and the distribution of porphyrin metabolites in plasma and dialysate were measured. In plasma, the group of patients with skin changes (referred as PCU = porphyria cutanea uremica) showed significantly increased uroporphyrin levels as compared to the non-symptomatic group. In addition, significant differences concerning the ratio uro-/coproporphyrin in plasma were shown: non-symptomatic patients with 0.87, as opposed to the PCU group with 3.7. Considerable differences between the level of vitamin ingestion were identified between the groups. Patients with PCU took distinctly less vitamins C, E and B than patients without symptoms.

[Dialysis associated skin changes]

Patients with end-stage renal disease often suffer from different dermatologic conditions. Reports indicate that 50-100% of patients with end-stage renal disease have at least one cutaneous disorder. The persisting chronic uremia is responsible for a variety of structural and functional skin changes. Dialysis or even renal transplantation leads to an improvement of some uremia associated skin disorders, others however can persist.