1. Department of Genitourinary Medicine, Cambridgeshire Community Services NHS Trust, Bury St Edmunds, UK
2. Department of Genitourinary Medicine, Royal Liverpool University Hospital, Liverpool, UK
3. St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, UK
4. Guy's and St Thomas' NHS Foundation Trust, London, UK
5. Department of Genitourinary Medicine, Royal Free London NHS Foundation Trust, London, UK