Complications

• post-herpetic neuralgia may be seen following herpes zoster infection
  • defined as pain persisting 3 months or more after resolution of the cutaneous HZ lesions.
  • is the most common complication
  • incidence and severity increases with age
    
• temporary paralysis (1-5%) usually follows the dermatome involved and may affect bladder and bowel function
  
• disseminated HZ occurs primarily in immunocompromised patients; it usually presents with a dermatomal eruption followed by dissemination but may also present with a diffuse varicella-like eruption (1)
  • systemic dissemination may accompany the skin changes with involvement of the lung, liver, and brain
• visceral dissemination is associated with a mortality rate of 5% to 15%, with most deaths attributable to pneumonia
  
• neurologic complications of HZ may include:
  • acute or chronic encephalitis
  • myelitis
  • aseptic meningitis
  • polyradiculitis
  • retinitis
  • autonomic dysfunction
  • motor neuropathies
  • Guillain-Barre syndrome
  • hemiparesis
  • cranial or peripheral nerve palsies
    
• more common complications include bacterial superinfection by Staphylococcus aureus or Streptococcus pyogenes, scarring, and hyperpigmentation
  • secondary infection - especially dangerous in the ophthalmic division.

Reference:

• (1) Werner RN et al. European consensus-based (S2k) Guideline on the Management of Herpes Zoster - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV), Part 1: Diagnosis. J Eur Acad Dermatol Venereol. 2017;31(1):9-19.
• (2) Homler H.Herpes zoster: query and concern. Mayo Clin Proc. 2009 Jul;84(7):663; author reply 663-4.