Reckless; a skin eruption (4)
I believe the answer is:
rash
I believe this clue is a double definition.
'reckless' is the first definition.
(I know that reckless can be written as rash)
'a skin eruption' is the second definition.
(I know that skin eruption can be written as rash)
(Other definitions for rash that I've seen before include "not considered" , "Impetuous; skin ailment" , "complaint" , "Over-hasty, reckless" , "Foolhardy with skin ailment" .)