From reading what is going on with your boss' daughter, I'm shocked that they have not addressed the problem and are treating symptoms
for over 1.5 years. An opening in the skin, the largest organ of the body, especailly an organ of elimination and protection from germs/organisms/etc., is a serious medical condition. She should go to another doctor, such as a dermatologist, to address the original problem. After that, it would be possible to address any dependency or addiction issues.