Although there's certainly much more to be said and I'd be happy to answer follow-ups, you might be interested in this answer I wrote about Italy in the immediate post-war era. In short, Italy was the first Axis power to surrender. So although the country spiraled into societal collapse following the armistice, Italy nonetheless began discounting its occupation when the war was still underway. This had the final result of bringing about a more distracted and less punitive occupational policy more geared towards the need to win the ongoing war than anything else. The existence of Italian-American voting blocks in the United States might have also contributed to a more lenient occupational policy.
Now, although I'd need to ask what precise sort of social stigmas you are referring to in order to answer more precisely, I would also add that the early armistice and ensuing Italian Civil War allowed the country's post-war political order to claim descent from the antifascist militias which formed after the creation of Mussolini's German-backed rump-state in 1943. This post-war order governed by former antifascist militants indeed not only legitimized the new ruling class, but also legitimizing radical-leftist parties. Although these parties were only included in government in the first year or so of the new Republic's life, the United States and its western european partners feared these parties could "flip" Italy to the Eastern Bloc should they be able to lead a governing coalition: an incentive to be as accommodating as possible towards Italy to irretrievably lodge it into the fold of the West.
I also answered a few other questions about post-war Italy which might provide you some additional information: