I regularly find tufts like that from Tiffany - always from her belly fur - I'm not even sure she scratches there, as I don't see her doing so - they seem to just drop out of their own accord
but she does have a skin sensitivity, as she develops a bald patch after her annual booster, so I suspect the tufts I find are linked to something - as the loss of fur doesn't seem to bother her, I have never investigated it