What Are The Chronic Red And Itchy Bumps On My Legs?

Hi there: about 2 years ago I got an itch on my leg, it starting getting worse over the cold weather. I have used many lotions and creams nothing seem to work. I went to a dermastologist he said it was ezcema, but none of the medications worked.
Now they tell me is not ezcema, but something different, I have little red, sometimes purple little bumps on both of my lower legs they itch a lot ..