Adolescent affliction (4)
I believe the answer is:
acne
'adolescent affliction' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for acne that I've seen before include "Teenage skin blemish" , "Teenage spots" , "Skin complaint" , "Adolescent skin disease" , "Pimply skin condition of adolescence" .)