Well, as others have pointed out, authoritarian nationalist collectivist ideas were myriad and possibly inevitable as of the end of WWI in some form or another.
Fascism, the weird Italian mishmash of socialism, syndicalism, authoritarianism, nationalism, republicanism, futurism, romanticism, and militarism, was a specific product of the OTL chain of events, and any time in its history could have morphed into something else Left or Right or Other.
Even before WWI Italian political ideas were heading towards areas associated with Fascism, however. Corradini's authoritarian nationalism, Pannunzio's nationalist-leaning radical syndicalism, ideas towards nationalist state socialism, Gentile's Actualism philosophy, futurism... The use of the term Fasci to describe a group (it's equivalent to the German 'Bund' or English 'Union') predates Fascism.
So Italy-wise you could certainly see some near-parallel arize, or even something called "Fascism" that's vastly different from OTL's Mussolinian party.