hi my 2 year old son has a red blotchy rash in a small area on his right check this appeared a couple of days ago after he was hit with a toy at first it was just a red mark but over the last day or two it has come out in small blister like bumps surrounded with a red mark that has been getting worse each day. He does not seem to be ill, no temperature, still has a good appetite and still as energetic as normal.