Grossed Out!

I am a new school nurse and have a student that I think has scabies. This student has a history at the school for poor hygiene and is a 'picker'- she constantly picks at her arms making any injury worse and creating new injuries where there previously weren't any. I have been educating her and have made numerous calls to her mother about this problem. Mom says there is nothing she can do because student won't stop picking. Well over the last week her hands have become covered with red bumps, some of them scabbed, some raw from scratching, some just red skin. And the skin between her thumb and pointer finger is thick and rough. Her mom said she took her to the doctor and I called and confirmed that she did visit the doctor, but couldn't tell me anything else except that she can be in school as long as she started her medicine, which mom says she did. Everyone is just grossed out, teachers, students, even me (although I act totally professional and non judgemental, or course) and I feel guilty that I didn't recognize that it was scabies on her first visit with the bumps. Has anyone else had any experience with something like this? Any thoughts or scabies recommendations are appreciated!