The Varicella-zoster virus lies dormant in the cell body of sensory neurons in the dorsal root ganglion. This virus causes chickenpox and herpes zoster; Chickenpox follows initial exposure to the virus and is typically a relatively mild, self-limited childhood illness with a characteristic exanthem. The virus remains dormant in the nervous system after a bout of chickenpox. Depending on the location of the virus, a reactivation causes and outbreak of shingles along the affected nerves.