Porphyria Cutanea Tarda — SCE Dermatology MCQ

Correct answer: A — Regular venesection and avoidance of precipitants (alcohol, oestrogens)

The correct answer is A, regular venesection and avoidance of precipitants (alcohol, oestrogens). PCT results from reduced hepatic uroporphyrinogen decarboxylase activity, causing hepatic and cutaneous accumulation of porphyrins; excess iron in the liver drives this enzyme deficiency, so serial phlebotomy to reduce iron stores is the established first line treatment. Removing triggers such as alcohol, oestrogens, hepatitis C and iron supplementation is equally essential, since continued exposure perpetuates porphyrin overproduction and blistering. This man's alcohol use and hepatitis C are classic precipitants that must be addressed alongside venesection to achieve remission, typically demonstrated by falling urinary uroporphyrin and clinical resolution of fragility and blistering. Why the other options are wrong: C. Oral Dapsone: Dapsone is used in neutrophilic dermatoses and dermatitis herpetiformis, not PCT, and does not address the underlying iron driven enzyme defect. E. Topical corticosteroids: These do not influence porphyrin metabolism or hepatic iron overload and have no proven benefit in PCT; skin fragility and photodamage are due to porphyrin toxicity, not an inflammatory process steroids would treat. D. Beta-carotene supplementation: This is used for erythropoietic protoporphyria to improve light tolerance, not PCT, and has no effect on uroporphyrin levels or iron overload. B. Oral Prednisolone: Systemic steroids do not correct the metabolic defect or iron excess and are not part of standard PCT management; they may even exacerbate skin fragility. Key point: In PCT, correcting hepatic iron overload with venesection and eliminating precipitants (alcohol, oestrogens, untreated hepatitis C) is the disease modifying cornerstone of treatment, not symptomatic skin therapy.

Reference: British Porphyria Association, Porphyria Cutanea Tarda (PCT) FAQs, treatment section: venesection and avoidance of precipitants (alcohol, oestrogens) as first line management, https://porphyria.org.uk/porphyria-cutanea-tarda-pct-faqs/