User Tools

Site Tools


zoster

herpes zoster (shingles)

introduction

  • reactivation of the latent varicella virus manifests as herpes zoster (shingles)
  • patients with shingles should be regarded as being contagious for varicella and isolated from non-immune patients
  • reported annual incidence of HZ varies from 1.5-3.4 cases per 1000 individuals
  • lifetime risk of HZ is 10-20% with incidence substantially rising with age > 60 years
  • neonates with congenital chickenpox are at high risk of HZ during infancy.
  • risk factor for the development of HZ is reduced cell-mediated immune system:
    • the normal aging process
    • immunosuppressive Rx
    • HIV/AIDS (15x risk)
  • the US has started a program to reduce zoster in the elderly by offering vaccination to those over age 50yrs as it appears to reduce the incidence of zoster by 96% if one gives two doses of Shingrix between two and six months apart to adults who are at least 50 years old - this is far more effective and longer lasting than the older Zostavax.1)
    • unfortunately in Australia we still only have access to Zostavax as of 2017 2)
  • 60% of patients have varying degrees of dermatomal pain prior to rash eruption

complications

  • complications of shingles may include post-herpetic neuralgia, and disseminated zoster with visceral, central nervous system and pulmonary involvement
    • postherpetic neuralgia is more common in patients older than 50 years
    • immunosuppressed patients may develop disseminated disease with viraemia and haematogenous spread:
      • eg. infection of lungs, liver, brain or neurologic (eg, motor neuropathies of the cranial and peripheral nervous system, encephalitis, meningoencephalitis, myelitis, Guillain-Barré syndrome)

ED Mx of acute shingles

  • see also below for additional HZ ophthalmicus Mx
  • isolate from non-immune contacts
  • aciclovir if within 72hrs of onset 800mg 5/day for 10 days (Aust. PBS Auth)
  • analgesia - consider controlled-release oxycodone in the acute phase
  • consider post-exposure vaccination for non-immune contacts - see varicella-zoster virus (chickenpox/shingles)

herpes zoster ophthalmicus (HZO)

  • see also emedicine
  • refers to HZ involving the trigeminal ganglion, first division (ophthalmic) of the trigeminal nerve and nasociliary nerve
  • 10-25% of all cases of shingles
  • 50% of patients with HZO develop complications
  • sequelae can be devastating including blindness as well as post-herpetic neuralgia
  • prodromal phase of influenza-like illness with fatigue, malaise, and low-grade fever that may last up to 1 week prior to the development of unilateral rash over the forehead, upper eyelid, and nose.
  • Hutchinson sign is the appearance of typical HZ lesions at the tip, side, or root of the nose and indicates nasocilary nerve involvement and increased risk of corneal involvement
  • ocular complications include:
    • periorbital and conjunctival edema (1 wk)
    • secondary Staphylococcus aureus infection (1-2 wk)
    • focal scleral atrophy (late)
    • punctate epithelial keratitis (swollen epithelium, 1-2 d)
    • dendritic keratitis (tree branch–like epithelial defects, 4-6 d)
    • stromal keratitis (fine infiltrates beneath the surface, 1-2 wk)
    • deep stromal keratitis (lipid infiltrates and corneal neovascularization, 1 month to years)
    • neurotrophic keratopathy (erosions, persistent defects, corneal ulcers; months to years)
    • uveitis, with inflammation and iris scarring leading to glaucoma and cataract (2 weeks to years)
    • acute retinal necrosis/progressive outer retinal necrosis

ED Mx of HZO

  • examine for nasociliary nerve involvement and ocular involvement
  • examine for the blinking reflex and if compromised, an eye lubricant is needed to prevent corneal desiccation injury.
  • oral antivirals ASAP (Aust. PBS Authority) as per HZ Rx but can be started irrespective of onset duration given benefits are likely to outweigh risks
    • as VZV DNA may persist in cornea for up to 30 days, prolonged antiviral Rx should be considered if ocular involvement, the elderly or immunocompromised
    • iv antiviral Rx should be considered for evidence of retinal involvement which may then require months of oral Rx
  • oral corticosteroids:
    • may reduce immediate pain but not post-herpetic neuralgia
    • ONLY prescribe if concurrent antiviral Rx AND only if low risk patient (eg. non-diabetic, no PH gastritis)
  • do NOT start ophthalmic topical steroids without ophthalmology consultation, but this may be indicated for Rx of stromal keratitis, episcleritis or uveitis
  • early ophthalmology review

Ramsay Hunt Syndrome

  • an acute peripheral facial neuropathy associated with erythematous vesicular rash of the skin of the ear canal, auricle (also termed herpes zoster oticus), and/or mucous membrane of the oropharynx as a result of reactivation of varicella virus within the geniculate ganglion.
  • aka geniculate neuralgia or nervus intermedius neuralgia
  • may involve CN VIII, IX, V, and VI in order of frequency, as well as the facial nerve
  • accounts for 16% of unilateral facial nerve palsy in children over age 6yrs, and 18% of facial palsies in adults
  • it is rare in children under 6 yrs age
  • facial palsy recover rate is < 50%

clinical features

  • patients usually present with paroxysmal pain deep within the ear which precedes onset of rash by hours or days.
  • zoster lesions in one of the facial zones:
    • auricularis (ie. around the ear or inside the external auditory canal)
    • facial (ie. lower half of face)
    • occipito-collairs
    • ipsilateral anterior two thirds of the tongue or soft palate (lingual nerve)
  • +/- facial nerve palsy (Bell's palsy like)
    • +/- auditory symptoms such as tinnitus, deafness (in 50%), vertigo, nystagmus and ataxia

ED Mx of Ramsay Hunt syndrome

  • ocular lubricants and eyelid management to prevent corneal erosions from dehydration as per Bell's palsy
  • oral aciclovir as per shingles
  • oral corticosteroids are often used as per Bell's palsy but little evidence for long term benefits
  • analgesics - consider controlled-release oxycodone
  • vestibular suppressants if severe vertigo
  • consider topical local anaesthetics to auditory canal lesions if otalgia problematic
zoster.txt · Last modified: 2018/03/21 10:17 (external edit)