England ran in six tries in Manchester, with Northampton's Harry Mallinder scoring 12 points.
Sale's George Nott opened the scoring for England before Harlequins' Sam Aspland-Robinson helped the hosts to a 17-3 half-time lead.
Quins' Joe Marchant, Worcester's Jack Singleton, Bath's Zach Mercer and a penalty try saw England home.
In the final game of three during the day at Manchester City Academy Stadium, Leonardo Mantelli's drop-goal was the Italians' only points until they crossed in the final minutes through Lorenzo Masselli.
England, who won this tournament in 2013 and 2014, next face Scotland at the same venue on Saturday, followed by Australia on Wednesday, 15 June.
Earlier in the day, Wales scored three tries inside the first 20 minutes that looked to have set the platform for a win over Ireland, but it was only 17-15 at the break to the men in red.
Two more tries in the second half saw Ireland home 26-25, despite a late try from Wales' Keelan Giles, his second of the game, but the touchline conversion to win the match was missed.
At the AJ Bell Stadium, the other venue for the three-week tournament, Scotland opened with a hugely impressive 15-10 win over Australia. Adam Hastings, son of Scottish legend Gavin, kicked a penalty and a conversion.
At the same venue, reigning champions New Zealand started the defence of the title they have won five times in eight tournaments, by running in nine tries in a 55-0 win over Georgia.
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England began the World Rugby Under-20 Championship with a comfortable 48-10 bonus point win over Italy.