What does it mean when you have a reoccurring scab like bump that comes up in your head?

Non healing lesion: It may be some underlying lesion that appears to be a non-healing scab. Get the area examined by a dr. to see if it is something that needs to be treated professionally. best wishes.

Sun damage scalp: Most likely sun damage caused a lesion called actinic keratosis. This is a benign lesion but should be evaluated by a doctor to ensure that this is not an early skin cancer