sqad is about but I would question the adverb "expert".
I assume that you mean the outside of the nose (skin) and not the inside of your nose ?
Almost certainly, based on your medical history and posts, that this is a psychosomatic problem and difficult to deal with.
It would require you taking anxiolytic medication if you feel that your itchy nose is a big deal e.g Asian or Valium.
This is outside of my expertise.
Have you been prescribed such medication in the past?
If you have, then I should start them again.