Derm Cases · Medicine
OSCE — Porphyria cutanea tarda (PCT)
Eight-minute OSCE station on Porphyria cutanea tarda (PCT): focused history, examination priorities, investigations, emergency and definitive management.
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Study tools
Target exams
Brief (to candidate)
You will assess a patient with a presentation consistent with Porphyria cutanea tarda (PCT).
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.
Clinical context
Porphyria cutanea tarda (PCT) is the most common type of porphyria, caused by reduced activity of uroporphyrinogen decarboxylase (UROD) in the liver, producing photosensitive blistering lesions on sun-exposed skin (dorsal hands, face, forearms), skin fragility, hypertrichosis, hyperpigmentation, and milia. Risk factors include hepatitis C virus (HCV), alcohol excess, iron overload (HFE mutations C282Y/H63D), oestrogens, HIV, and renal dialysis. The hallmark biochemical finding is elevated urinary uroporphyrin and heptacarboxyl porphyrin (which fluoresces pink-red under Wood's lamp) and a plasma fluorescence emission peak at 619-620 nm. Treatment: therapeutic phlebotomy (target ferritin ~ 25
[2]Candidate tasks
- Clarify onset, severity, associated features, and red-flag symptoms.
- State focused examination priorities.
- List first-line investigations and any named score/criteria.
- Give immediate resuscitation steps.
- Outline definitive management with doses/routes where standard.
- Name complications and disposition (ward / HDU / theatre / discharge safety-net).
- Mention one special-population modifier (pregnancy, child, elderly, CKD).
- Give immediate resuscitation steps.
- Outline definitive management with doses/routes where standard.
- Name complications and disposition (ward / HDU / theatre / discharge safety-net).
- Mention one special-population modifier (pregnancy, child, elderly, CKD).
Examiner checklist
| Domain | Pass behaviours |
|---|---|
| Definition | Correct working diagnosis language |
| Assessment | Focused, prioritised, red flags sought |
| Investigations | Appropriate first-line + interpretation |
| Emergency care | ABC / time-critical actions first |
| Definitive care | Specific drugs/procedures, not generic phrases |
| Safety | Photosensitive blistering with skin fragility on the dorsal hands — check urinar |
| Safety | Elevated liver enzymes with skin fragility — PCT is a hepatic porphyria; assess |
| Safety | Acute neurological attacks (abdominal pain, neuropathy, hyponatraemia, seizures, |
| Communication | Clear plan and safety-netting |
Model outline
Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use guideline-standard therapy with named agents and doses. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays critical care for non-urgent imaging.[1]
References3ShowHide
- [1]Wang B, Bonkovsky HL, Lim JK, Balwani M AGA Clinical Practice Update on Diagnosis and Management of Acute Hepatic Porphyrias: Expert Review Gastroenterology, 2023.PMID 36642627
- [2]Salameh H, Sarairah H, Rizwan M, Kuo YF, Anderson KE, Singal AK Relapse of porphyria cutanea tarda after treatment with phlebotomy or 4-aminoquinoline antimalarials: a meta-analysis Br J Dermatol, 2018.PMID 29750336
- [3]Sarkany RPE, Phillips JD The clinical management of porphyria cutanea tarda: An update Liver Int, 2024.PMID 38813949