My Puppy Has A Lump On Her Head?!?

My Spanish Alano puppy is three months old, when she came to us from Spain she already had a scar on her head from trying to escape out a fence. When her and my other year old dog play together, they can get a little ruff. And I think that is the reason, why her scar opened up a little. Now she has a lump on the top of her head, where her scar opened up. I can't tell if she is in any pain, but I was wondering if there was anyway i could stop the swelling and ease the pain if she is in any? Please help me!