Hi, my son had this on his chest. When he was born, it looked just like a faint mark, then gradually turned a deep red and very raised. Its called a strawberry neavus. They fade with time and apparently disapear altogether. My son is now nearly 4 and its much fainter now. (I dont notice it at all although it covers the whole side of his chest!)
When he was born they said they wouldnt use surgery on it as they are harmless, and they will disapear.
I hope this helps, but if your worried, see your health visitor or doc..