endocrine and metabolic disorders
Porphyria Cutanea Tarda
Treatment of Porphyria Cutanea Tarda
Four complementary therapeutic strategies are available: Reduction of body iron stores Increase in porphyrin excretion Treatment of chronic hepatitis C and HIV infection, when present Cessation of alcohol use, smoking, andestrogenuse, when present These strategies can be combined for more rapid remission, although combining them is not usually necessary. The treatment is monitored by determinations of serum ferritin (if iron reduction therapy is used) and urinary porphyrin excretion every other or every 3rd month until full remission. Patients should stop alcohol use and smoking (including marijuana). Iron removal by therapeutic phlebotomy is usually effective. A unit of blood is removed every week or two. When serum ferritin falls slightly below normal, phlebotomy is stopped. Usually, 6 to10 sessions are needed. Urine and plasma porphyrins fall gradually with treatment, lagging behind but paralleling the fall in ferritin. The skin eventually becomes normal. After remission, further phlebotomy is needed only if there is a recurrence. Ongoing iron reduction therapy is also recommended when hereditary hemochromatosis is present. In these patients the target serum ferritin is 50 to 150 ng/mL (50 to 150 microgram/L). Low-dosechloroquineorhydroxychloroquine, 100 to 125 mg orally twice a week, removes excess porphyrins from the liver and perhaps other tissues by increasing the excretion rate. Higher doses can cause transient liver damage and worsening of porphyria. When remission is achieved, the regimen is stopped. Chloroquineandhydroxychloroquineare not effective in advanced renal disease, and phlebotomy is usually contraindicated because of underlying anemia. However, recombinant erythropoietin mobilizes excess iron and improves the anemia enough to permit phlebotomy. In end-stage renal disease,deferoxamineis an adjunct to phlebotomy for reduction of hepatic iron, the complexed iron being removed during dialysis. Dialyzers with ultrapermeable membranes and extra high blood flow rates are needed. Patients with overt PCT and hepatitis C infection should be evaluated for treatment with Treatment . Previous iron depletion augments the response to interferon-based antiviral therapy, but such depletion seems unimportant because of current treatment using highly effective direct-acting antiviral medications. Remission of PCT skin lesions following antiviral treatment has been reported, but documentation of complete reversal of the metabolic defects and long-term improvement is lacking. Nevertheless, it seems worth first treating and curing hepatitis C virus infection before deciding on iron reduction or Children with symptomatic PCT are treated with small-volume phlebotomies or oralchloroquine; dosage is determined by body weight. Skin symptoms occurring during pregnancy are treated with phlebotomy. In refractory cases, low-dosechloroquinecan be added; no teratogenic effects have been recognized. Depending on the degree of hemodilution and iron depletion, the skin symptoms usually abate as pregnancy advances. Postmenopausal estrogen supplementation or other estrogen therapy, such as for men with prostate cancer, is interrupted during treatment for PCT. Stoppingestrogensoften induces remission. Substituting systemic with transdermalestrogensis sometimes done if postmenopausal symptoms are troublesome, but there may still be some risk due to the degree of systemic absorption. in management of PCT is not recommended ( Treatment references ). 1.Rudnick S, Bonkovsky HL: Hepatitis C and porphyria cutanea tarda in 2020.Aliment Pharmacol Therap51:1432–1434, 2020. doi: 10.1111/apt.15728 2.Fujita Y, Sato-Matsumura KC: Effective treatment for porphyria cutanea tarda with oralcimetidine.J Dermatol37(7):677–679, 2010. doi:10.1111/j.1346-8138.2010.00838.x 