iWhat causes itchy red bumps on the joints of hands and feet?

I seem to have the same problem. I get them alot when it is cold. They only occur on my fingers and toes, around the the joints. They start out as a little pin point of red that is slightly raised, that feels like a sliver is in there(but nothing is in there), and they itch, then it is like they burst and get bigger and swell the whole area. They are painful to scratch. Mine can take weeks to month to completly heal. Sometimes they do occur on my finger tips or alongside my fingers, but mostly it affects the area around my finger and toe joints. I have been researching everywhere and had even whent to the doctor. The doctor referred my to a rhumatologist. She didn't believe it was that because at the time, my only one hand was affected. The doctor said rhumatoid affects btoh sides during an attack. I really wish I knew what it was, I am desperatly seeking an answer also. Best of luck and keep posted if you find anything.