welcome to HealthcareMagic
I am concerned that you were hit on the head.
Did you consult a physician for that??
Did you develop any symptoms like headache, nausea
We need to properly investigate and cure your wound.
For your question , yes it can be a cause of scar or bald spot.It depends on how severe the wound is.Dont worry , these days there are a lot of therapies for that.
Just consult a physician in your area for the time being as it can develop infection and pus and aggravate the condition.