My 9 yr old had a fever of 101.7 last night. The fever broke today, but a portion of his lip has swollen up. Not sure if it s a cold sore because I ve never seen a cold sore get this big and swollen. The under side of it is white. He says it feels like he s got a fat lip. Should we bring him in or will this go away by putting cold sore medicine on it? I m assume the fever caused it. Please advise what the best action is to take. Thank you, Brenda.