Chronic sores. Help ID. Video.

I could use some help identifying what is going on here... https://youtu.be/d57HdlDVAO4

You will see a sore that I get. It can start as a something like a zit. I have had these on the back of my head, face, arms and knees. The sore ends up developing a scaly scab and can be painful to the touch and mildly itchy at times. The scab it not like your normal wound scab. Pulling the scab off can bring some relief from the pain. Often times the scab appears to have roots. The sore does not heal until I eventually dig out the white ball. Based on how sensitive to touch it is I can tell if there is still something in there. Often times there are more than one white ball. I have pulled out 5 or so in a single session. when the white balls get pulled out there is a rush of blood that soon stops. Picking at the wound produces little blood if any, however removing the white balls causes a lot of bleeding. Any info would be appreciated. I can show pics of the sores and scabs with roots if it will help.