I'm glad you have an appt with a derm.
There are a few conditions that can cause things like this - https://www.healthline.com/health/waking-up-with-scratches#scratches-from-a-pet-or-another-person (They include a section on the paranormal, and I don't know why - you can ignore that part.)
One of the conditions listed in the first article is dermatographia - https://www.mayoclinic.org/diseases-conditions/dermatographia/symptoms-causes/syc-20371411 They include a photo, which has scratches ALL OVER. I am not familiar with it enough to know if it can only cause a few scratches, or it needs to be all over the body like that.
In any case, none of them sound serious, which is the good news. :)