Needing to scratch (5)
I believe the answer is:
itchy
'needing to scratch' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for itchy that I've seen before include "Suffering from a rash?" , "Needing a scratch" , "Wanting a scratch?" , "Causing irritation to skin" , "Fidgety" .)