Hello. I Have These Sores That Occur Every Few Weeks

Hello. I have these sores that occur every few weeks on my upper middle back. They take a very long time to go away. I have A LOT of freckles and moles on my back and it just seems like I get more every year. It’s the only place on my body that I have so many. Many of my freckles are misshapen and vary in color. What could this be? I have pictures that I can send.