My Scalp Is Very Sore To The Touch On One

My scalp is very sore to the touch on one side - extending from behind ear to near top of head. I have some swelling in the area. Just started today. No injury cause. I do have a sore near the area that rarely heals. It has the same sort of tenderness as when you get a goose egg from bumping into something. Should I be concerned or seek medical attention?