During the pandemic, Covid-19 rules concerning travel to and from European Union countries is updated frequently.
According to this, Italian Minister of Health extends the restrictions until the end of April 2021 for every traveller who have stayed or transited in the 14 days prior to entering Italy.
So, upon returning to Italy, it is mandatory to undergo:
a swab (molecular or antigenic test) with negative result carried out within 48 hours, prior to entry to Italy;
fiduciary isolation and health supervision for 5 days, regardless of the result of the swab referred to above;
a further swab at the end of the 5 days fiduciary isolation period.
There are also some exemptions or/and limitations in case of entry, transit or stay in Italy, which can be consulted from https://www.esteri.it.