Herpes zoster (HZ), caused by reactivation of varicella-zoster virus (VZV) that was acquired during a primary varicella infection, is characterised by dermatomal pain and papular rash.

Risk factors:

• 50 years of age

• Immunocomprimised
  • HIV
  • Chronic corticosteroid use (immunosuppresion)
  • Chemotherapy (immunosuppresion)
  • Malignancies (immunosuppresion)
• Female

PC

*Presence of risk factors

• Localised pain in a dermatome for 2-3 days
  • Burning, stinging, tingling (ranging from mild to severe)
  • Pain can precede the rash by days to weeks
  • Most commonly affected ganglia - thoracic and trigeminal nerves
• Pruritis
• Erythematous maculopapular rash
  • Followed by appearance of clear vesicles, eventually pustulate forming crusts
• Corneal ulceration ( if CNV affected)

Systemic symptoms - fever, headache, malaise, fatigue (uncommon)

Abnormal presentations (immunocomprimised patients):

• Absence of vesicular lesions (more likely if elderly)
• Prolonged rash: new lesions developing >7 days after presentations (usually in immunocompromised)
• Zoster sine herpete: describes pain without rash (rarely occurs)
• Disseminated disease: features of pneumonia, encephalitis, hepatitis (at risk if severely immunosuppressed)