why does a herpes flare up reappear in the same spot?


Herpes flare ups will typically show up in the same spot year over year and never spread to new locations. Why is that?

In: 31

Herpes lives in nerve ~~endings~~ roots around/close to your spine, when it multiplies and wins the fight against your immune system (usually because the immune system is busy fighting wars on multiple fronts) it then pops up with blisters. This is also why people usually get them when they are sick or run down.

It happens in the same location because it made its home in that nerve and that is where the nerve travels.


I get mine when I am really stressed, sick or if I get sunburn. I can guarantee if I get sunburned lips, I will have a cold sore pop up within 24 hours.


Edit: this is way above eli5 here…

Thank you to /u/reaspiration for the correction/clarification [in this comment](https://www.reddit.com/r/explainlikeimfive/comments/11840k7/eli5_why_does_a_herpes_flare_up_reappear_in_the/j9fzigs/)

>Primary infection occurs at a mucocutaneous surface with retrograde transportation of the virus to the peripheral sensory ganglia, maintenance of the viral genome within the peripheral sensory ganglia, and periodic reactivation with antegrade transmission to the nerve endings and mucocutaneous surface.

[Source](https://jamanetwork.com/journals/jamaneurology/fullarticle/795486) – the same source /u/reaspiration provided

What are **peripheral sensory ganglia**?

Sensory ganglia are enlargements along peripheral nerves. The ganglia consist of neurons whose dendrites contribute to the peripheral nerves and whose axons form dorsal rootlet connections to the spinal cord and brain stem.


What are **dorsal roots (spinal nerve)**?

Each spinal nerve has two roots, a dorsal or posterior (meaning “toward the back”) one and a ventral or anterior (meaning “toward the front”) one. The dorsal root is sensory and the ventral root motor; the first cervical nerve may lack the dorsal root. Oval swellings, the spinal ganglia, characterize the dorsal roots.


If possible try to get Valacyclovir or one of its knock offs. It is like magic if you take it when a new one is coming on. The window is small but if you take one early enough it will bitch slap the blisters before they form.

Herpes flare ups occur when the virus is reactivated from a dormant state. This usually happens when the body’s immune system is weakened or when the person is under stress. The virus tends to remain in the same spot because once it has been reactivated, it replicates in the same location and can remain dormant there until it is reactivated again.