Definition
An acute viral infection of the sensory nerve caused by a variety of chicken pox virus.
Etiologic Agent
Varicella – zoster (V-Z) virus
Has been found to cause two diseases, varicella and herpes zoster.
Partially immune occurring in individuals due to previous varicella infection
Incubation period
- Incubation period of Herpes zoster is unknown, its believed to be 13-17 days.
Period of communicability
- A day before the appearance of the first rash to 5-6 days after the last crust.
Mode of transmission
• Direct contact – through droplet infection; airborne spread
• Indirect contact – through articles freshly soiled by secretions and discharge from the infected person.
Pathogenesis
- The virus is identical to the causative agent of varicella.
- After the primary infection, the varicella zoster virus may persist in a dominant state in the dorsal root ganglia.
- The virus may emerge from the site in later years either spontaneously or in association with immunosuppression to cause herpes zoster.
- It produces localized vesicular skin lesions confined to a dermatome and severe neurologic pain the peripheral areas innervated by the nerves arising in the inflamed root ganglia. This infection usually occurs in adult.