I asked by Italian son-in-law for help on this. Here is what he tells me.
Vul. stands for vulnus. Examples are: vulnus punctum for a
stab wound, vulnus scaplet for a knife wound.
So, what's the etymology of sclopeticum? What I have found is this:
The word "sclopus" (or scloppus) refers to "the sound made by striking
on the cheek with a finger when the cheek is fully inflated"
I think it makes sense/ This is the source -