Herpes zoster

Background

  • Caused by Varicella Zoster Virus (VZV) causing Varicella (chicken pox) and later zoster (shingles)
  • Virus is dormant in dorsal root ganglion and reactivates causing characteristic rash in dermatomal distribution
  • Occurs once immunity to virus declines (elderly, immunosuppressed, post transplant, HIV)

Clinical Features

  • Prodrome: Headache, malaise, photophobia
  • Antecedent pruritis, paresthesia, pain to dermatome 2-3 days prior to rash
  • Maculopapular rash (see below) progresses to vesicles, may coalesce to bullae, in dermatomal distribution lasting 10-15 days
  • Does not cross midline
  • Typically affects chest/face
  • Herpes Zoster Ophthalmicus
  • Herpes Zoster Oticus (Ramsay Hunt Syndrome)
Herpes Zoster

Differential Diagnosis

Varicella zoster virus

Diagnosis

  • Further evaluation if disseminated VZV
  • Immunocompromised
  • If more than 3 or more dermatomes affected
  • If young, previously healthy adult-may be initial presentation with HIV
  • Further evaluation for pneumonitis, hepatitis, encephalitis as clinically indicated
  • Atypical illness/severe disease
    • Viral Culture, antigen, PCR of vesicle fluid

Treatment

  1. Pain
    • PO narcotics
  2. Antiviral
    • Reduces risk/duration of postherpetic neuralgia
    • Immunocompetent patients:
      • Give acyclovir if <72hr of onset of rash or >72hr if new vesicles present/developing[1]
      • Acyclovir 800mg PO 5x/day x 7d
    • Immunosuppressed patients:
      • Give antiviral therapy at any stage of onset of rash
      • Acyclovir 10 mg/kg IV q8h OR 800mg PO 5x/day x 7d or foscarnet for acyclovir-resistant VZV, disseminated zoster, CNS involvement, ophthalmic involvement, advanced AIDS, recent transplant

Not Benificial

  • Steroids not shown to be beneficial

Disposition

  • Admit for disseminated VZ, CNS involvement, severely immunosupressed
  • Healing of lesions may take 4 or more weeks[2]

Complications

Prevention

  • Pt is contagious until lesions are crusted over
  • Consider varicella-zoster immunoglobulin to immunosupressed, pregnant, neonate contacts
  • Zoster vaccination if >60

See Also

References

  1. Cohen, J. Herpes Zoster. N Engl J Med 2013; 369:255-263. DOI: 10.1056/NEJMcp1302674
  2. Sampathkumar P, et al. Herpes zoster (shingles) and postherpetic neuralgia. Mayo Clin Proc. 2009; 84(3):274–280.