England had a perfect start when scrum half Dan Robson (Hartpury Coll & Gloucester Rugby) struck in the second minute from a quickly-taken penalty after a dynamic opening spell.
Flanker Sam Northcote-Green (Dulwich Coll & London Wasps) added a second 20 minutes later and captain George Ford (Rishworth & Leicester Tigers) converted all four tries.
But England lost control of the middle of the game against a rugged Azzurri side intent on kicking long for territory and contesting the contact areas aggressively.
Ruscano fly half Ippolito Menniti kicked two first half penalties and indiscretions after the interval meant Italy were still in the game at 14-12 down with 20 minutes remaining.
"Credit to Italy, they stuck at it, played with a lot of fire, tackled hard and made us work hard at the breakdown," said head coach John Fletcher, who made 10 changes to the starting line-up following last month's 33-16 win over France.
"We created a lot of opportunities in the first half but only scored twice. We were inconsistent and lacked a bit of precision, and you could argue we left six or seven tries out there.
"But overall I'm very pleased because you have to learn by playing in difficult environments against sides who use different tactics. We kept playing the way we wanted to and kept on pressing, then took two chances towards the end."
Ben Ransom (Tonbridge & Saracens); Chris Elder (RGS High Wycombe & London Wasps), Jamie Elliott (Bedford & Northampton Saints), Tommy Bell (Bacup and Rawtenstall GS & Sale Sharks), Mark Jennings (Lymm HS & Sale Sharks); George Ford (Rishworth & Leicester Tigers, Captain), Dan Robson (Hartpury Coll & Gloucester Rugby); Nick Auterac (Oaklands College & Saracens), Nathan Moris (Sedbergh & Newcastle Falcons), Kyle Sinckler (Epsom Coll & Harlequins), George Merrick (Whitgift & Harlequins), Dominic Barrow (Prince Henry's GS Otley & Leeds Carnegie), Billy Vunipola (Harrow & London Wasps), Sam Northcote-Green (Dulwich Coll & London Wasps), Matt Kvesic (Worcester Sixth Form Coll & Worcester Warriors).
Koree Britton (Ivybridge Coll & Exeter Chiefs) for Moris 48, Anthony Brennan (Twyford CofE & London Wasps) for Sinckler 36, Will Skuse (Bryanston & Bath Rugby) for Northcote-Green 48, Will Spencer (St Paul's Catholic & London Irish) for Merrick 65, Charlie Gordon (Wellington College and London Wasps) for Robson 57, Ryan Mills (Hartpury Coll & Gloucester) for Bell 50, Elliot Daly (Whitgift & London Wasps) for Elder 52.
Italy scorers: Penalties: Menniti 4.
England scorers: Tries: Robson, Northcote-Green, Britton, Vunipola. Conversions: Ford 4.
Referee: James Jones (Wales). Attendance: 3,000.
England Under 18 fixtures 2009/10
December 13: England U18 30 Australia Schools 28
February 21: England U18 33 France 16
March 6: Italy U18 14 England U18 28
March 28: Wales U18 v England U18 (Swansea)
April 2: England U18 v Ireland (Llandovery 4pm)
April 7: England U18 v Scotland (Llandovery 2pm)