I have to wonder what antibiotic you were given for your infection.

Some of them cause nerve damage.

I had a staph infection from a black fly bite, over 30 yrs ago. It was pretty awful with high fever swollen nodes over my ear, and swollen face (it was on my eyelid). I was in Maine where they are common and ended up in the hospital ER. The choices for treatment were much less back then, so I was put on Erythromycin (a penicillin substitute). But today, with MRSa and the more toxic antibiotics, it is possible to have more residual problems after treatment.

After an antibiotic and some improvement, I was left with high blood pressure for life. My doctor believed at the time, that the staph infection was the culprit. So I have been on various blood pressure medications since then.

I was given Vancomyicin interveniously twice a day for over a month. This is the second to the strongest antibiotic, and it barely killed the skin folical staph! The tachycardia started at that time, but I already had the high BP, and the shoulder numbness. But in retrospect, I guess the antibiotic was better then the alternative...

Well, Vanco is tough on people. It has a boatload of nasty side effects... Including irregular heart beats.
Nerve damage. But as you say there isn't
Much choice in your situation.

Just in the past few weeks I've noticed a spot near the upper middle of my back that itches a bit. When I scratch it with backscratcher, I've noticed it's numb. No tingling, pain, or pins/needles—just itching & numbness.

Doc

Interesting the doctors failed to mention this, even though they was the tachycardia in the hospital and following months afterward. My GP (that I fired) told me point blank that it was all psychological, even knowing about my month long IV of Vanco, and knowing that I was going hyperthyroid, with a history previously of bloodsugar problems and hypothyroid, it was all in my head... The ignorance, kind of broadsided me...
I was about one day away from checking out, as the staph was climbing my arm as my doctors scratched their collective heads... After telling my surgeon 3 days in a row at I had Staph, they finely drew a sample, and rushed me to the hospital next door for surgery. That was on Friday the 13th...