Itchy Bumps on Skin

Hello,
I have been getting these itchy small bumps on my thumb. And I have been using hydrocortinsone on it and it does work until I stop using it, then the bumps return and always in the same general area of my thumb. They are not appearing anywhere else on my body. I have been to the doctors before and they had told me it was herpes just by looking at it, no tests of any kind. I know I don't have it. I think it is an allergic reaction to something but I have never had any allerges. I moved to a different state a year back and before I came here I had no problems.
I need help,
does anyone have any idea what it could be, something that looks like herpes but its not.

Thank you.