endocrine and metabolic disorders
Erythropoietic Protoporphyria and X linked Protoporphyria
Treatment
Avoidance of sun exposure through use of protective clothing and opaque sunscreens Afamelanotidefor prevention of phototoxic events and amelioration of phototoxic reactions Symptomatic treatment for skin burning with cold compresses, nonsteroidal anti-inflammatory drugs (NSAIDs), and topical and/or oral corticosteroids Management of hepatobiliary complications Treatment for erythropoietic protoporphyria and X-linked protoporphyria is similar. Patients with erythropoietic protoporphyria or X-linked protoporphyria should avoid sun exposure; protective clothing, hats, and light-opaque titanium dioxide orzinc oxidecontaining sunscreens should be used. , a long-acting congener of melanocyte stimulating hormone which leads to increased production of eumelanin, can be administered once every 60 days as a subcutaneous implant, decreases photosensitivity, allows longer exposure to light, and improves quality of life ( Treatment reference ). Oral beta-carotene, an antioxidant, reduces photosensitivity. However, patient adherence with beta-carotene is often poor because it is not very effective in controlling symptoms and also causes orange skin pigmentation; thus it is often tried but usually not continued. Beta-carotene dose depends on patient’s age (see table Doses of Beta-Carotene in Erythropoietic Protoporphyria and X-Linked Protoporphyria ). Medications that trigger acute porphyrias need not be avoided (see theDrug Database for Acute Porphyriaor theAmerican Porphyria Foundation drug database). In some patients, acute skin symptoms can be alleviated by cold baths or wet towels, analgesics, and topical and/or oral corticosteroids. However, many patients do not find such measures very effective. Symptoms can take up to a week to resolve. If these measures are ineffective (eg, patients have increasing photosensitivity, rising porphyrin levels, progressive jaundice), giving hematin and/or red blood cell hypertransfusion (ie, to above-normal hemoglobin levels) may reduce protoporphyrin overproduction. Administration of bile acids may facilitate biliary excretion of protoporphyrin. Oralcholestyramineorcharcoalhave been used to interrupt the enterohepatic circulation of protoporphyrin and increase fecal excretion. Oralvitamin E, 800 units per day, is also used with the hope that it will exert an antioxidant and hepatoprotective effect, although objective evidence of benefit is scant. Patients who develop decompensated end-stage liver disease require Liver Transplantation . As with Hematopoietic Stem Cell Transplantation is curative for EPP but is not routinely done because the risk typically outweighs the benefits. The strategy of hematopoietic stem cell transplantation after liver transplantation cures EPP and prevents recurrent EPP from damaging the allograft, but the optimal timing of this strategy has not been established. Patients should be protected from operating room lights during liver transplantation or other prolonged surgery to avoid serious phototoxic injury to internal organs. Light sources should be covered with commercially available filters that block wavelengths ~380 to 420 nm. Endoscopy, laparoscopy, and brief (< 1.5 hour) abdominal surgery do not usually cause phototoxic damage. Operating room lights can cause phototoxic injury to internal organs in patients with erythropoietic protoporphyria. Regular physician-patient consultations that provide information, discussion, and opportunities for genetic counseling together with physical checkups are important. Liver function and red blood cell and plasma protoporphyrin levels should be checked annually. Patients with abnormal liver function test results should be evaluated by a hepatologist; a liver biopsy may be needed to stage the degree of fibrosis. Patients with known chronic liver disease should undergo screening liver ultrasonography, CT, or MRI every 6 months to check for hepatocellular carcinoma. Vitamin Dlevels should be checked because deficiency is common (patients tend to avoid sun exposure); supplements are given if levels are low. All patients with EPP and XLPP should receive Hepatitis A (HepA) Vaccine and 1.Langendonk JG, Balwani M, Anderson KE, et al:Afamelanotidefor erythropoietic protoporphyria.N Engl J Med373:48–59, 2015. doi: 10.1056/NEJMoa1411481. 