Herpesvirus infections of the nervous system
Donald H Gilden, et al.
Nature Clinical Practice Neurology (2007) 3, 82-94
VZV-associated viremia and lymphotropism have been documented during varicella, herpes zoster, PHN and zoster sine herpete, and even in normal healthy adults.
The detection of VZV DNA [40, 41] and VZV-specific proteins42 in blood MNCs of some patients with PHN and zoster sine herpete, [43, 44, 45] as well as in tissue of patients with chronic VZV ganglionitis,  might reflect low-level productive infection in ganglia—a hypothesis that is supported by favorable clinical responses in some PHN patients treated with antiviral agents. [47, 48]
After varicella, the varicella zoster virus (VZV) becomes latent in ganglia along the entire neuraxis; its reactivation can lead to herpes zoster, vasculopathy, myelitis, necrotizing retinitis or zoster sine herpete
Zoster sine herpete
It would be rash to ignore it
Neurology February 1, 2011 vol. 76 no. 5 416-417
6. Varicella-Zoster Virus Infection
Donald H. Gilden
University of Colorado Health Sciences Center
2003. pp 10
A case of neuropathic brachioradial pruritus caused by cervical disc herniation http://www.nature.com/nrneurol/journal/v4/n6/full/ncpneuro0807.html
Molecular mechanisms of varicella zoster virus pathogenesis
Nature Reviews Microbiology 12, 197–210 (2014)