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Herpes zoster
Make it clearer
Herpes zoster, which most people know as shingles, is not a new infection. It is the reactivation of the varicella-zoster virus, the same one that caused an earlier bout of chickenpox. After that infection the virus did not go away: it stayed latent, meaning quiet and alive, inside the sensory ganglia, which are clusters of nerve cell bodies next to the spinal cord and in the head.
What keeps it quiet is, in large part, cell-mediated immunity, the part of the immune system that keeps watch over the inside of cells. Shingles is thought to appear when that surveillance is lost and the virus is no longer held in check.
The virus then starts to multiply, and the virions, the particles of the virus, travel down the nerve to the patch of skin that ganglion serves. There they cause local inflammation and blisters. The virus comes out through the patch of skin served by the nerve where it lay dormant.
In brief
Herpes zoster, or shingles, is a viral illness caused by reactivation of the varicella-zoster virus, which lies latent in the sensory ganglia after a previous case of chickenpox.
Latency is largely controlled by cell-mediated immunity, and reactivation is thought to result from the loss of that surveillance.
Once reactivated, the virus replicates and virions travel along the nerve to the skin that ganglion supplies, producing local inflammation and blisters.
The virus comes out through the patch of skin served by the nerve where it lay dormant.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingHerpes Zoster, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated