Spots on head -- lack of care (8)
I believe the answer is:
rashness
'lack of care' is the definition.
(being rash is acting without proper care)
'spots on head' is the wordplay.
'spots' becomes 'rash' (I've seen this before).
'on' means one lot of letters go next to another.
'head' becomes 'ness' (ness is a headland).
'rash'+'ness'='RASHNESS'
(Other definitions for rashness that I've seen before include "Impulsiveness" , "Imprudence" , "Audacity" , "indiscretion" , "intemperance" .)