Key man who introduced antiseptics for a burn (7)

'a burn' is the definition.
(thesaurus)
'key man who introduced antiseptics' is the wordplay.
I cannot quite understand how this works, but
'key' could be 'e' (musical key) and 'e' is found within the answer.
'man' could be 'r' (abbreviation for rook, a chess piece or 'man') and 'r' is found in the answer.
The remaining letters 'blist' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for blister that I've seen before include "Result of friction" , "Friction mark" , "Bubble on the skin filled with fluid" , "Give hair dryer treatment" , "Sore bubble on skin" .)
This clue could be a double definition.
'key man who introduced antiseptics' is the first definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'a burn' is the second definition.
(thesaurus)
'for' acts as a link.
Can you help me to learn more?
(Other definitions for con that I've seen before include "Opposed" , "Deceive; prisoner" , "politician who's in the right" , "Diddle" , "Swindle; steer" .)
