21 yr old granddaughter will occasionally pull off a toe nail, this last incident she pulled off four toe nails. She seems to have a "high tolerance to pain" because she does not react to pain or show pain. We find out sometime days later that she has done this. She is diagnosed with PDD-NOS Autisim Spectrum, developmental delayed, bio polar, she is high functioning. My concern is that... could there be a reason for her to pull them off due to not being able to communicate with us that she has some sort of itching, pain, etc.