What Causes A Neck Hole Which Goes Deep Inside?

Hello. My friend has had this hole in the back of her neck, no thicker than a pencil, and when I looked at it, it seemed to go kind of deep. I know that the hole was not the result of self-injury, and despite repeated requests to go to see a doctor, her parents have not taken her. Instead, they have tried to treat it themselves which has not had any success. I've never seen this before and I was wondering if anybody could tell me if it has a specific name and if it can be treated and properly closed.