rash around mouth

Ma
Hello my son is 2, and randomly spiked a little fever yesterday, couldn't nap because he was so uncomfortable, kept making noise when he was trying to nap, breathing fasts etc. 
which is normal when you don't feel good. He MAY be getting his top molars...? Idk. He hasn't been around anybody sick so I don't think hes got a cold. Anyway, he LOVES his binky, and when i took it a out early last night I noticed he had instantly broke out into this rash around his mouth. Hes had this before but not this bad at all, this look more like it hurts, where the others before were just bumps. . Any ideas how to help get rid of it?