I have patches of red dry skin, what do i do?

so, ok. i ran the LA Marathon, and ever since then i have been getting theses rashes on my body. i dont know if the running had anything to do with it, but they are freaking me out. it began with one like under my right boob, but then later on more appeared on my right side of my stomach. so what i guess what i'm trying to get to is how can i get rid of them. it's like i have dry patches of red skin, really scare stuff. HELP!!|||Try Eucerin cream, its really good.