Disambiguating Churg-Strauss from Wegener's

Disambiguating Churg-Strauss from Wegener's

How do you go about disambiguating Churg-Strauss from Wegener's? And
why do they treat it w/ prednisone, instead of azathioprine/
methotrexate, or dexamethasone?

And what is this "molecular pathology" I've been hearing about?


Thanks!!!!