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For further information, see CMDT Part 6-45: 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 and 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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Stopping all triggering medications and stopping or reducing alcohol consumption may lead to improvement
Phlebotomy at a rate of 1 unit every 2–4 weeks will gradually lead to improvement
Hydroxychloroquine, 200 mg orally twice weekly, alone or in combination with phlebotomy, increases excretion of porphyrins and improves skin disease
Deferasirox, an iron chelator can also be beneficial
Most patients improve with treatment
Barrier sun protection with clothing is required for prevention; sunscreens do not provide adequate protection