Title should use describe, not explain.
This guy is tatted up.
I’d think the nerve virus introduced via needle as most likely etiology.
Doesn’t Shingles usually follow a dermatome?
Years ago, I had excruciating pain, w/o any rash, that precisely mapped to T2 dermatome. Lasted 3 weeks. Nothing touched the pain. I still have a single shrinking area just below the elbow inside of the forearm on the affected side that is intermittently extremely itchy without any visible skin effect.
Never got any diagnosis and none of the medical people I consulted had heard of dermatome pain w/o a rash. Came out of nowhere and vanished the same way. Horrible experience.