Pimply condition (4)
I believe the answer is:
acne
'pimply condition' 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 "Skin condition associated with pimples" , "Spotty coverage" , "Skin condition prevalent among teenagers" , "Skin problem, mainly of teenagers" , "Spotty skin condition" .)