Cases of idiopathic hepatitis in children have been reported around the world. Elisabeth Mahase looks at what we know so far How many children have been affected?The World Health Organization has so far reported 169 cases of acute hepatitis of unknown origin from 11 countries in Europe and the US, as of 21 April 2022.1 In the UK, where the increase in cases was first noted at the start of 2022, 11