• A common dermal and neurologic disorder caused by reactivation of the varicella-zoster virus that has remained dormant within dorsal root ganglia, often for decades, after the patient's initial exposure to the virus in the form of varicella (chickenpox). It is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area.
  • Acute infectious, usually self-limited, disease believed to represent activation of latent varicella zoster virus in those who have been rendered partially immune after a previous attack of chickenpox; it involves the sensory ganglia and their areas of innervation and is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area.