1. The University of Nottingham; c/o Cochrane Skin Group; Room A103, King's Meadow Campus Lenton Lane Nottingham UK NG7 2NR
2. Centre for Research in Environmental Epidemiology (CREAL); c/ Doctor Aiguader 88 Barcelona Catalunya Spain 08003
3. The University of Nottingham; Centre of Evidence Based Dermatology; Lenton Lane Nottingham UK NG7 2NR
4. The University of Nottingham; Division of Epidemiology and Public Health; Clinical Sciences Building Nottingham City Hospital NHS Trust Campus, Hucknall Road Nottingham UK NG5 1PB
5. CLĺNICA GO&FER; Unit of Dermatology; Riera Blanca 6-8, L´Hospitalet Barcelona Spain 08903
6. St George's Hospital; Department of Dermatology; London UK
7. Hôpital Henri Mondor; Department of Dermatology; Créteil France 94010