The reason it's not healing is that you keep yanking the scab off when you comb your hair.

Clip the hair in that area and cover the scab with a bandaid for a couple of weeks to give it time to actually heal. Change the bandaid daily, and use a tiny bit of ointment or grease or oil of some sort (anything that will help keep the scab flexible) on the pad of the bandaid.

The scab doesn't come off. It's a hard scaly thing. My hair is cut very short above the scab.

See a dermatologist ... it could be a skin cancer.

I was just there last week. He examined it and said nothing bad about it. Good response tho. I remember getting bit by a bug there and it never healed up for some reason.