What Causes An Itchy Bump On The Ankle?

Hi, I have a bump that's been sore and very itchy for about 2 weeks on my ankle. Until yesterday I thought it was just a patch of dry skin. However, I can definitely feel a small bump under the skin. It gets more itchy and a lot more sore when I'm exercising to the point where it's distracting. I had an incredibly horrible sun burn 2 years ago and I'm wondering if that could be a factor.