What does it mean if I keep getting rashes/pimples, but only on one finger? - eviltoast

I know medical questions aren’t allowed on this subreddit, but this one was so mundane and yet so oddly specific that I figured this was the best place to ask.

My left middle finger keeps getting an annoying, itchy rash that is covered in tiny pimples. It’s worst on the sides of the finger. I know eczema is a thing, but I’ve never heard of it being specific to one finger.

The closest thing I could find is maybe dyshidrosis, which can give you itchy in the side of your finger. but I think those bumps have fluid in them like blisters, and I don’t think my bumps have fluid.

If it helps, I usually wear rings on my middle fingers, but I haven’t worn any in a while, and my right middle finger is totally fine. I’ve been having problems with this specific finger getting insanely itchy rashes for over a year or two.