1. St John's Institute of Dermatology; St Thomas’ Hospital; King's College; London; SE1 7EH; U.K
2. Department of Dermatology; St. Mary's Hospital; London; U.K
3. Faculty of Life Sciences; University of Manchester; Michael Smith Building, Oxford Rd; Manchester; M13 9PT; U.K
4. Faculty of Medicine; St. Mary's Campus; Imperial College; London; U.K