Have a crazy rash problem!?

So at night, every night like clockwork, I get this incredibly itchy rash on my upper chest with bumps like are large enough to look like mesquito bites. By morning the rash on the chest is gone, but on my jawbone the rash pops up with the same bumps. It is like this every day for the past few weeks. It is getting annoying and I'm getting concerned. Please share your insight, thanks!