If you had chicken pox in the past, you have Herpes Zoster living in your nerves today.

What causes them to activate is mysterious, and may be due to dietary factors (too much arginine) or some stressor.

It is certainly possible to have nerve pain due to Herpes Zoster and not have the blistering rash. Some doctors don't understand this. But if you have blood work done to show titres, they may be elevated for this virus.

I only had a small cluster of blisters with my shingles. Since then I have pain in that arm now and then.
Hubby had huge crops of blisters with his shingles on his trunk, and he only gets pain rarely...mostly in spring. He developed shingles after a hornet sting. He also had them in one ear, which was very painful. The sting was on his forearm.

If the virus is in your ganglia, you always have it. Everyone is different and can express it in a unique fashion.

I have some skepticism about jumping on another new medical intervention, without knowing the outcome. There is so much doctor caused grief with medicine today, it may pay to be careful.