Porphyria cutanea tarda

Diagnosis: Porphyria cutanea tarda

Clinical Presentation

Porphyria cutanea tarda

Clinical History

Skin fragility, vesicles, and bullae on sun-exposed areas (dorsal hands, forearms, face). Hypertrichosis. Evaluate for hepatitis C, alcohol use, iron studies, HIV.

Treatment

Avoid triggers: alcohol, estrogens, sun exposure. Phlebotomy (500mL every 2 weeks until ferritin ~20). Low-dose hydroxychloroquine (100-200mg 2×/week). Treat hepatitis C if present. Iron reduction.

Differential Diagnosis

• Pseudoporphyria (drug-induced) • Epidermolysis bullosa acquisita • Bullous pemphigoid • Dermatitis herpetiformis • Polymorphous light eruption • Solar urticaria

Key Learnings

• Most common porphyria — caused by deficient uroporphyrinogen decarboxylase (UROD) • Photosensitivity with skin fragility, vesicles, bullae on dorsal hands (sun-exposed) • "Catfacing" — milia and scarring on dorsal hands are characteristic • Hypertrichosis (especially temples/periorbital) is a common clue • Strongly associated with: hepatitis C, HIV, alcohol, estrogen use, iron overload, hemochromatosis • Wood lamp: coral-pink fluorescence of urine (elevated uroporphyrins) • Urine porphyrins confirm diagnosis — elevated uroporphyrins and heptacarboxylporphyrins • Treatment: phlebotomy (reduce iron) or low-dose hydroxychloroquine (mobilize porphyrins via urine)

Tags: case, dermatologist, dermatology, kodachrome, Porphyria cutanea tarda