My 17 year old son has develop a rash on his lower abdominal now he has it on both his arms and he's getting it on his face. It's red and it looks like an allergic reaction but I don't think the bumps are getting bigger especially on him elbows they are red and he itches very much. The ones on his abdominal seems to be sore across his lower abdominal it looks like he has lots of pimples all together can someone please help me.