Bumps on my baby

My son had a fever the other day of 101.8 and it only last a Day and then nothing the next day, and then this rash but we haven’t changed anything he wasn’t out side much we think it might be allergies and we have no idea what it is plzzz opinions. He’s not itching he’s eating fine and he’s playing he’s not acting weird he’s perfectly ok otherwise. Just these are everywhere and we don’t no why.