Each year, about ten people in Britain die from allergic reactions to food. The case of Natasha Ednan-Laperouse, who died after eating a sandwich from Pret a Manger, was a nasty reminder of how allergies can claim young lives at any moment. But it also raises a difficult question: to what extent are businesses that serve food culpable? Why do so many people, after this case, want to blame Pret and only Pret?

It’s territory with which I am familiar, as a mother of two children with severe allergies.