If you have arthritis in your thumb, is it a good or bad idea to exercise your thumb?

I suspect I may have arthritis in my right thumb -- all of a sudden it's steadily painful, but I am only guessing (I have not yet consulted my doctor). I wonder if using one of those hand exercisers would be a helpful thing to do, or would it just make matters worse? I'm talking about those items you grip and then squeeze together.