My bird has a blister thing

by Pru
(Caboolture qld )

Hi my bird is a male galah he lost a big feather from his wing I was not worried but a few weeks later he got a blister thing where the feather was and it is weeping and smelly but he is happy loud and playful it does not seem to bother him much but I can't get him to stop picking at it what can I do