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Updated: Oct 21 2018

Porphyria Cutanea Tarda

  • Snapshot
    • A 50-year-old man complains of open, non-healing blisters on the dorsal surfaces of his hands. He has a history of untreated chronic hepatitis C infection. While he tries not to drink, he admits to having one glass of wine over the holidays. He denies any abdominal pain.
  • Introduction
    • Blistering cutaneous photosensitivity caused by hepatotoxic triggers
    • Autosomal dominant or sporadic defect in heme synthesis
      • deficiency of hepatic uroporphyrinogen decarboxylase
        • accumulation of uroporphyrinogen III
    • Recurrent flares triggered by hepatotoxins that upregulate heme/P450 synthesis
      • alcohol and estrogen = most common triggers
      • viral hepatitis
      • HIV
      • iron
    • Epidemiology
      • most common form of porphyria
      • middle-aged men and women
      • younger women on oral contraceptives
  • Presentation
    • Skin findings
      • non-healing blisters, erosions, and ulcers
      • in sun-exposed areas (face, neck, dorsal hands, forearms)
      • hypertrichosis of face
      • hyperpigmentation of skin
    • Non-skin findings
      • no abdominal pain (as in other porphyrias)
      • red-brown urine (port-wine urine) from porphyrin pigment
  • Evaluation
    • Diagnosis by urine studies
      • ↑ urine uroporphyrin levels (2-5x above coproporphyrins)
  • Differential Diagnosis
    • Pseudoporphyria (from NSAIDs)
    • Porphyria variegata
    • Acute intermittent porphyria
    • Erythropoietic protoporphyria
      • burning pain and erythema develops on skin minutes after sun exposure
      • no scarring or blistering
      • protoporphyrins elevated in plasma and RBCs
      • treatment: limit sun exposure; beta-carotene reduces photosensitivity
  • Treatment
    • Avoid exposures (alcohol, estrogen, other hepatotoxins)
    • Sunscreen use
    • Iron removal by phlebotomy
    • Chloroquine
  • Prognosis, Prevention, and Complications
    • Prognosis
      • complete clinical clearing in between 2 months and 2 years after stopping triggers exposures
    • Prevention
      • avoid triggers
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