so my son ran a fever yesterday.. gave him Tylenol it seemed like it went down. he had gotten a rash…

so my son ran a fever yesterday.. gave him Tylenol it seemed like it went down. he had gotten a rash right after he got his sono so I thought it was the gel he had a reaction to...and his nose is stuffy and he keeps holding his ears. he was fussy all yesterday. like I couldn't pick him up...At 2 in the morning his rash spread all over his body.. and he's still congested in the nose and he keeps holding his ears... should I take him to the er? they still haven't called me back about what they found on the ultrasound they did on him yesterday.