Sounds like just what all my 1968/69-born friends have on their upper arms, it's where they were giving the smallpox vaccinations. Just before phasing them out.
I got the shot as well, but not on my arm. My mom had the joy of watching the doctor (not my regular doctor) take me from her, and inject me right over my spine. At about the 5th and 6th thoracic vertebrae level...well, that's where the scar is NOW. Who knows where the injection site was when I was a FEW MONTHS OLD...
yep, my dad was thinking of us moving to Vancouver, BC after I was born, and I guess the doc thought that Canada was just some HUGE hotspot for smallpox, and he injected me.
My mom said she just sat there with her mouth wide open for a moment, then grabbed me out of his arms and left the office, sobbing.
And, to this day, that area is really sensitive for me. The scar is HUGE (compared to the scar on an arm; think of how much more a back grows than an arm) and it's just not "sound" in that area.
Sorry to hijack.