OSCE — Varicella & Herpes Zoster (Chickenpox and Shingles) · MBBS OSCE

Brief (to candidate)

You will assess a patient with a presentation consistent with Varicella & Herpes Zoster (Chickenpox and Shingles).
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.

Clinical context

Varicella-zoster virus (VZV, human herpesvirus 3 / HHV-3) is a neurotropic double-stranded DNA alpha-herpesvirus that produces two distinct clinical syndromes. Primary infection — varicella (chickenpox) is a generalised, pruritic, vesicular rash appearing in crops at different stages simultaneously (papules, vesicles, pustules, crusts together), with fever and malaise, mainly in children. The virus then becomes latent in the dorsal root and cranial-nerve ganglia and reactivates decades later as herpes zoster (shingles) — a painful, unilateral, dermatomal vesicular rash that does not cross the midline, typically in older or immunosuppressed adults. Zoster complications: postherpetic neuralgia

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).

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	Painful unilateral vesicular rash in a single dermatome not crossing the midline
Safety	Zoster affecting the ophthalmic division of the trigeminal nerve (forehead/eye),
Safety	Varicella pneumonia in an adult, smoker, pregnant or immunocompromised patient -
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.