Updated: 10/21/2018

Porphyria Cutanea Tarda

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
2
0
0
Topic
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

Please rate topic.

Average 5.0 of 1 Ratings

Questions (2)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
EXPERT COMMENTS (2)
Private Note