Everything, Everything Amandla Stenberg, Nick Robinson, Anika Noni Rose. Directed by Stella Meghie. Rated PG-13. Opens Friday citywide.

There’s nothing like incurable illness to add a tinge of tragedy to young love. Following on the success of teen cancer romance The Fault in Our Stars, Everything, Everything (also based on a young adult novel) presents a beautiful but fragile teenage girl who’s literally sickened by the world. Maddy (Amandla Stenberg) has an autoimmune disease that makes even the most harmless germs potentially life-threatening for her. She lives ensconced in a high-tech, germ-free house, protected by her strict doctor mother (Anika Noni Rose) and never allowed to go outside.

But once hunky, sensitive skater boy Olly (Nick Robinson) moves in next door, Maddy starts longing for something more, and the two begin a flirtation over text messages and online chats, depicted cleverly by director Stella Meghie in cute fantasy sequences. The romance between Maddy and Olly straddles the line between sweet and cloying, and Stenberg’s winning performance often overwhelms the blander Robinson. As cheesy as the love story can be, the heightened stakes (Maddy might literally die if she goes on a date!) effectively mimic the overdramatic feelings of teenage crushes.

It’s too bad, then, that the goodwill is shattered by a third-act twist that turns the story about one kind of disease into a story about a different kind of disease, undermining much of the thematic resonance in Maddy and Olly’s romance. The tragedy is undone by contrivance.