Synopsis
Distinguish primary varicella from zoster reactivation, recognise ocular, neurological and disseminated disease, treat promptly, and deliver current UK exposure prophylaxis and vaccination.
- Primary VZV causes chickenpox with crops of pruritic lesions at different stages; reactivation causes unilateral dermatomal shingles that usually does not cross the midline.
- Chickenpox spreads by respiratory and lesion contact from about 48 hours before rash until all lesions crust; uncovered or disseminated shingles can also transmit VZV.
- Adults, pregnant people, neonates and immunosuppressed patients have greater risk of pneumonitis, encephalitis and disseminated disease.
- Lesion-vesicle PCR is the preferred laboratory confirmation when appearance is atypical, disease is severe or public-health consequences are important.
- Treat uncomplicated shingles promptly, ideally within 72 hours, using oral aciclovir 800 mg five times daily for seven days or a suitable equivalent regimen.
- Use intravenous aciclovir 10 mg/kg every eight hours for encephalitis or severe immunocompromised VZV, with renal adjustment, hydration and one-hour infusion.
- UKHSA recommends oral aciclovir or valaciclovir as preferred PEP for susceptible high-risk contacts from day 7 through day 14 after exposure.
- From January 2026, eligible children in England receive routine MMRV at 12 and 18 months, with cohort-specific catch-up; use current Green Book eligibility rather than an old schedule.
Key red flags
Eye pain, photophobia, reduced vision, red eye or vesicles on the forehead or nose needs same-day ophthalmic assessment for sight-threatening zoster.
Confusion, seizure, meningism, focal weakness, ataxia or stroke-like symptoms requires urgent CNS investigation and intravenous aciclovir.
Dyspnoea, cough, hypoxaemia or chest pain during chickenpox suggests varicella pneumonitis and requires hospital admission.
Widespread, haemorrhagic or necrotic lesions in an immunosuppressed patient may mark disseminated infection with visceral involvement.
Pregnancy with chickenpox or significant exposure requires urgent maternity and infection advice because maternal and fetal risks and PEP are time dependent.
A neonate exposed to maternal chickenpox from seven days before to seven days after delivery needs immediate specialist risk assessment under the current UKHSA pathway.
Forehead, upper-eyelid or nasal lesions with red eye, photophobia, pain or visual change indicate trigeminal involvement.
Painful auricular vesicles with ipsilateral facial weakness, hearing symptoms or vertigo suggests geniculate ganglion reactivation.
Lesions beyond the primary dermatome, haemorrhagic vesicles or systemic organ symptoms indicate viraemic spread, particularly during immunosuppression.
Investigation priorities
Confirm VZV in atypical, severe, disseminated or epidemiologically important rash.
Management branches
A generalised vesicular rash or disseminated zoster is suspected in a healthcare or shared setting.
- Separate the patient from susceptible pregnant, neonatal and immunosuppressed people and apply airborne plus contact precautions in healthcare.
- Establish rash onset, lesion distribution, immune status, pregnancy, respiratory and neurological symptoms and every significant contact during the infectious interval.
- Obtain lesion PCR when confirmation affects management or contact action, but do not delay treatment of severe disease.
- Inform infection prevention and health protection when exposure occurred in healthcare, care, maternity or another high-risk setting.
Routine childhood, catch-up, occupational, contact or shingles-vaccine eligibility is reviewed.
- Use the 2026 cohort table: eligible children receive combined MMRV at 12 and 18 months, with date-of-birth-specific transitional and catch-up arrangements.
- Offer targeted varicella vaccination to susceptible eligible contacts or workers under the Green Book, checking live-vaccine contraindications first.
- Offer recombinant shingles vaccine to eligible older and immunosuppressed adults according to the current age, interval and immune-status programme.