Recently, the mother of a wheezy toddler on my ward told me with pride how her e-cigarette had helped her give up a 20-smokes-a-day habit. There is much controversy amongst tobacco-control specialists about the merits of this increasingly popular smoking substitute. E-cigarettes are devices that look and feel like a conventional cigarette, but contain no tobacco, and deliver a ‘dose’ of nicotine as a spray when inhaled. A study in The Lancet from …