Destroy her last ten hives! (6,4)
I believe the answer is:
nettle rash
'hives' is the definition.
('nettle rash' can be a synonym of 'hives')
'destroy her last ten' is the wordplay.
'destroy' indicates an anagram (I've seen this in other clues).
'her'+'last'+'ten'='herlastten'
'herlastten' with letters rearranged gives 'NETTLE RASH'.
(Other definitions for nettle rash that I've seen before include "major irritant" , "Urticaria" , "Hives" .)