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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
Key points
- VZV reactivation in dorsal root ganglion — unilateral dermatomal vesicular rash, does NOT cross midline
- Prodromal pain 2-3 days before rash. Vesicles crust in 7-10 days
- Aciclovir 800 mg 5x daily for 7 days OR valaciclovir 1 g TDS — start within 72 hours
- Complications: post-herpetic neuralgia, herpes zoster ophthalmicus (Hutchinson's sign), Ramsay Hunt syndrome
- Shingrix vaccine offered from age 65 — >90% efficacy
Overview
Herpes zoster results from reactivation of VZV in dorsal root ganglia after chickenpox. Causes unilateral dermatomal vesicular eruption with pain. Thoracic dermatomes most commonly affected. Disseminated zoster in immunocompromised.
Epidemiology
Lifetime risk ~25-30%. Increases sharply after 50. PHN affects ~10-20% overall, rising to ~50% in over 70s. ~50,000 GP consultations/year in England.
Clinical Features
Symptoms
Prodromal burning/tingling pain in dermatomal distribution 2-3 days before rash
Unilateral grouped vesicles on erythematous base in a band
Severe neuropathic pain
Eye pain, redness, visual disturbance (V1 ophthalmic zoster)
Facial weakness + ear vesicles (Ramsay Hunt syndrome)
Signs
Unilateral dermatomal vesicular rash — does NOT cross midline
Most common: thoracic dermatomes
Hutchinson's sign: vesicles on nose tip — nasociliary V1, HIGH risk of ocular involvement
Ramsay Hunt: LMN facial palsy + ear canal vesicles (VZV in geniculate ganglion)
Investigations
First-line
Clinical diagnosisUnilateral dermatomal vesicles with pain
Second-line
VZV PCRIf diagnostic uncertainty or immunocompromised
Specialist
Ophthalmology reviewUrgent if V1 involvement — slit lamp examination
Management
NICE CKS — Shingles1
Antiviral (within 72 hours of rash)
- Aciclovir 800 mg 5x daily for 7 days (higher dose than HSV)
- OR valaciclovir 1 g TDS for 7 days
- Indications: age >50, non-truncal, moderate-severe, ophthalmic/Ramsay Hunt, immunocompromised
- IV aciclovir for immunocompromised or disseminated
2
Pain management
- Paracetamol +/- ibuprofen
- Neuropathic: amitriptyline 10-75 mg ON, gabapentin, pregabalin
- Topical capsaicin for localised PHN
3
Ophthalmic zoster
- URGENT ophthalmology referral
- Antivirals mandatory for 7-10 days
4
Ramsay Hunt
- Aciclovir 800 mg 5x daily + prednisolone 60 mg tapering
- ENT/neurology referral — worse prognosis than Bell's palsy
5
Vaccination
- Shingrix from age 65 — 2 doses, 2 months apart, >90% efficacy
- Also offered to immunocompromised from age 50
Complications
- Post-herpetic neuralgia: Pain >90 days after rash — commonest complication, debilitating in elderly
- Ophthalmic: Keratitis, uveitis, glaucoma
- Ramsay Hunt: Facial palsy + ear vesicles + hearing loss
- Secondary bacterial infection
UKMLA Exam Tips
- 1Unilateral dermatomal vesicles NOT crossing midline = shingles
- 2Hutchinson's sign: nose TIP vesicles = nasociliary V1 = HIGH risk eye involvement = URGENT ophthalmology
- 3Ramsay Hunt: LMN facial palsy + ear vesicles. Worse prognosis than Bell's palsy
- 4Aciclovir dose for shingles: 800 mg 5x daily (higher than HSV 200 mg)
- 5PHN treatment: amitriptyline, gabapentin, pregabalin
- 6Shingles is contagious to non-immune individuals — they get chickenpox, not shingles
practicetest your knowledge on Herpes ZosterApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — Dermatology and beyond.
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Herpes Zoster (Shingles): guidance by region
Recommendations, thresholds and pathways can differ. Open the page written for the jurisdiction you need.