No, because that would leave stubble, not a perfectly smooth scalp.
Dr. Rockoff
Can I ask as follow up question? Since her hair was brittle, could it just have broken off the hair?
I am really not sure about why your grandmother's hair fell out, but I can't see any connection with the veterinary conditioning product. Even severe burns wouldn't make a whole head of hair fall out, and it's clear the scalp wasn't burned.
My best guess would be alopecia totalis, an extensive form of alopecia areata. The cause is unknown, and the best course of action is to wait it out and use a wig to maintain appearance.
I suggest you ask the doctor who performed the biopsy whether the result is compatible with alopecia totalis.
Best.
Dr. Rockoff