The Chickenpox virus, Varicella Zoster, lies dormant in the nervous system after recovery from the acute illness. It is found specifically in the nerve cell bodies in the Doral Root Ganglion.
Shingles occurs as a result of reactivation of the virus, which then causes some of the nerve cell bodies to die off. The result is painful rash along the sensory dermatome of the affected nerve.
The rash disappears to leave a painful area characterised by areas of depigmentation and constant sensitivity known as allodynia.
