As a dermatologist, I am well aware that we are often perceived, unfairly, of course, as largely dealing with trivialities. Sometimes one’s medical colleagues think that we are not really proper doctors. And occasionally, when I have had one of those clinics when I have a succession of patients complaining that their eczema gets better when they use the treatment but comes back as soon as they stop, I am almost inclined to wonder whether I could be doing something more useful. But just once in a while you find that you have made a rather larger impact, literally, as you are about to read, than you could ever have imagined.