Porphyria Cutanea Tarda

Key Features

• 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

Clinical Findings

• 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

Diagnosis

• 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

Treatment

• 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