cause great fear or nervousness in; frighten.
"the rapid questions were designed to scare her into blurting out the truth"
synoniemen: frighten, make afraid, make fearful, make nervous, panic, throw into a panic; Meer
noun: scare; plural noun: scares
a sudden attack of fright.
"gosh, that gave me a scare!"
synoniemen: fright, shock, start, turn, jump; informalthe heebie-jeebies
"you gave me a scare—how did you get here?"
I think what Slash meant was that Izzy had a scare in the meaning above, drug related.
Not that he had a scar.