1. Centre for Pharmacoepidemiology and Drug Safety; Manchester Pharmacy School; The University of Manchester; Manchester Academic Health Science Centre; Room 1·134, 1st Floor, Stopford Building, Oxford Road Manchester M13 9PT U.K
2. Dermatology Centre; Salford Royal NHS Foundation Trust; The University of Manchester; Manchester Academic Health Science Centre; Manchester U.K
3. Department of Dermatology; East Lancashire Hospitals NHS Trust; Royal Blackburn Hospital; Blackburn U.K
4. Department of Dermatology; Western Infirmary; Glasgow U.K
5. St John's Institute of Dermatology; Guy's and St Thomas’ NHS Foundation Trust; London U.K
6. Dermatological Sciences; Institute of Cellular Medicine; Medical School; Newcastle University; Newcastle upon Tyne U.K
7. Department of Dermatology; Royal Victoria Infirmary; Newcastle Hospitals NHS Foundation Trust; Newcastle upon Tyne U.K