Overhasty (4)
I believe the answer is:
rash
'overhasty' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rash that I've seen before include "Skin redness" , "Ill-considered - break-out" , "Ill-considered - outbreak" , "Foolhardy about the skin infection" , "Hasty; skin disorder" .)