1. Clinic for Dermatology; University Hospital Essen; Germany
2. Institute for Health Services Research in Dermatology and Healthcare (IVDP); University Medical Center Hamburg-; Eppendorf
3. Department of Dermatology; University of Cologne; Cologne Germany
4. Klinik für Hautkrankheiten; Allgemeine Dermatologie und Venerologie; University Hospital Münster; Germany
5. Clinic and policlinic for Dermatology, Venereology and Allergology; Helios Klinikum Krefeld; Germany
6. Department of Dermatology; University Hospital Regensburg; Germany
7. Department of Dermatology; Freiburg University Hospital; Germany
8. Department of Dermatology; Ruhr-University Bochum; Germany