This might be the strangest question to ask, but I have to give it a try. I have had the best Dad in the world, but since my mother find him a cure for his Seborrhea and Vitilligo, he became very "confident" and he started neglecting the family. It might be a middle age crises (50yo) and maybe this is not the solution, but I believe that if he struggle again with his skin problem he would be nice and get back to family. I certainly wouldn't like to harm him anyway , but just to keep him occupied for a while (to make him reconsider his new life attitude and perspective)