I Got My Usual Allergy Shot, Which I've Been Getting

I got my usual allergy shot, which I've been getting without incident for many years.

This one hurt VERY much -- more than any other had. The next day, I noticed that area was numb -- about a 3" x 2" area. It is still numb, 4 days later. This has never happened before.

I am not worried about that area, because even if it never went away, i don't see that it will be a problem. But it sure seems that something went wrong.

Any thoughts or suggestions?

I'm 61, and in relatively good health-- controlled hypertension and high cholesterol, but no other major issues.