Dr David Harris qualified from the Royal Free Hospital School of Medicine in 1981 and spent his early years training in general internal medicine. His dermatological training started in 1987 at The Westminster and St Stephens Hospital, London, and included three years in the Academic Department of Dermatology in Edinburgh, Scotland. He returned to London to work at the Royal Free Hospital, before moving to the Cutaneous Surgery Center, University of Minnesota, Minneapolis, Minnesota, USA in 1992, where he was the Cutaneous Surgery Fellow. It was here that he gained complete training in laser surgery, Mohs micrographic skin cancer surgery and aesthetic dermatology.

From 1993 to 2002 he was Consultant Dermatologist to the Whittington Hospital NHS Trust. Dr Harris was the Founder and Director of The London Clinic of Dermatology at the Hospital of St John and St Elizabeth between 2002 and 2012. Dr Harris is a Fellow of the Royal College of Physicians and the American Academy of Dermatology, and a member of the British Association of Dermatologists. He is also a member of the European Society of Micrographic Surgery.