1 Department of Paediatric and Neonatal Surgery, St George's Healthcare NHS Trust and University of London, London SW17 0QT, UK.
2 Department of Paediatric Plastic Surgery, St George's Healthcare NHS Trust and University of London, London, UK.
3 Department of Paediatric Dermatology, St George's Healthcare NHS Trust and University of London, London, UK.
4 Department of Paediatric and Neonatal Surgery, St George's Healthcare NHS Trust and University of London, London SW17 0QT, UK stefano.giuliani@nhs.net.