Herpes zoster or Shingles is caused by varicella-zoster virus (VZV), the same virus that causes chicken-pox (varicella). Primary infection with varicella-zoster virus causes chicken-pox (varicella), then the virus persists in nerve ganglia of sensory but rarely motor nerves, in a latent stage. If the virus gets reactivated it causes herpes zoster, which presents as painful vesicles following a dermatome. It is more common in the elderly and the immunocompromised. Herpes zoster is a common skin and mucous membrane disease caused by reactivation of latent varicella zoster virus, which had lodged previously in nerve ganglia. Trigeminal nerve nuclei and thoracic spinal ganglia are the most commonly affected. Reactivation of latent varicella-zoster virus can be triggered by old age, that is why herpes zoster is common in the elderly, above 60 years of age. This is due to age related decline in specific cell mediated immune response to VZV. Other triggering factors are malignancies malnutrition, emotional stress, physical trauma, chronic diseases like diabetes mellitus and immunosuppression from drugs and HIV.¹,².
- Herpes zoster