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For further information, see CMDT Part 6-23: Porphyria Cutanea Tarda
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Noninflammatory blisters on sun-exposed sites, usually only the dorsal hands
Hypertrichosis, skin fragility
Associated liver disease
Elevated urine porphyrins
The disease is associated with ingestion of certain medications (eg, estrogens), and alcoholic liver disease or hepatitis C
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Painless blistering and fragility of the skin of the dorsal surfaces of the hands
Facial hypertrichosis and hyperpigmentation
In patients with liver disease, hemosiderosis is often present
Differential diagnosis
Pseudoporphyria: dialysis, medications (tetracycline, nonsteroidal anti-inflammatory drugs, voriconazole)
Contact dermatitis
Scabies
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Urinary uroporphyrins are elevated two- to five-fold above coproporphyrins
There may be abnormal liver biochemical tests, evidence of hepatitis C infection, increased liver iron stores, and various hemochromatosis gene mutations
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Phlebotomy without oral iron supplementation at a rate of 1 unit every 2–4 weeks will gradually lead to improvement
Hydroxychloroquine 200 mg orally twice weekly will increase the excretion of porphyrins, improving the skin disease
Deferasirox, an iron chelator can also improve porphyria cutanea tarda
Stopping all triggering medications and stopping alcohol consumption may lead to improvement
Most patients improve with treatment
Barrier sun protection with clothing is required for prevention