Rheumatoid arthritis is the inflammation of the joints usually small joints but large joints can also be affected. It is autoimmune disorder. Along with joints it can also affect skin, heart, blood vessels, lungs, kidney and some other organs. In your case nodule formation is also rheumatoid arthritis of skin. It will be good to see a doctor for its management.
I have the same problem. I'm 41 years old and my feet start out by being very itchy, then when I itch them they swell and it feels like someone has put a small rubber ball inside the ball of my foot and I walk on it. It hurts so bad. Why is this happening and how can I fix it?