DR8.3 | Varicella Zoster Recognition — Summary & Reflection

KEY TAKEAWAYS

Varicella zoster virus, a herpesvirus, causes two diseases. Varicella (chickenpox) is primary infection: a centripetal, intensely itchy rash whose hallmark is lesions in different stages simultaneously (the 'dewdrop on a rose petal' vesicle), distinguishing it from smallpox. After it resolves, VZV lies latent in dorsal root ganglia and, when cell-mediated immunity wanes (ageing, HIV, immunosuppression), reactivates as herpes zoster (shingles) — a unilateral, dermatomal band of grouped vesicles that does not cross the midline, often preceded by dermatomal pain. The key zoster complication is post-herpetic neuralgia (pain >3 months after rash onset, commonest in the elderly); zoster ophthalmicus threatens sight. A Tzanck smear shows multinucleate giant cells (herpesvirus, not subtype); PCR distinguishes VZV from HSV. Treat with early aciclovir/valaciclovir (within ~72 h for zoster; in varicella, for those at risk of severe disease), manage PHN with neuropathic agents, refer zoster ophthalmicus urgently, and prevent with varicella and zoster vaccination.

REFLECT

Think of a patient you have seen with chickenpox or shingles — or the next one you are likely to meet. Could you confidently name the recognition feature at the time: the lesions in different stages at once for varicella, or the dermatomal band that stops at the midline for zoster? For a patient with shingles, did you (or would you) check for ophthalmic involvement and start antivirals within the 72-hour window, and would you have thought to consider underlying immunosuppression in a young or unusually widespread case? Consider how you would explain post-herpetic neuralgia to an elderly patient and what you would offer for prevention. Tying these recognition patterns to a real encounter is what makes them stick.