Herpes Zoster

Herpes zoster is an acute infectious viral disease of an extremely painful and incapacitating nature which is characterized by inflammation of dorsal root ganglia or extramedullary cranial nerve ganglia, associated with vesicular eruptions of the skin or mucous membranes in areas supplied by the affected sensory nerves. The virus is the same as that of varicella or chicken pox (the VZ virus) and occasionally the two diseases are clinically nearly indistinguishable. It is now believed that herpes zoster is caused by reactivation of the latent VZ virus which had been acquired during a previous attack of chicken pox. In essence, a primary infection by the VZ virus results clinically in chicken pox, while a recurrent infection results clinically in herpes zoster.