Teen's bane (4)
I believe the answer is:
acne
'teen's bane' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for acne that I've seen before include "Skin spots" , "(Inflammation causing) spots" , "Pimply ailment of adolescnce" , "Spotty skin condition" , "Adolescent skin disease" .)