1. CVderm - Centre of Excellence for Health Services Research in Dermatology; Institute for Health Services Research in Dermatology and Nursing; University Medical Center Hamburg-Eppendorf; Hamburg Germany
2. Psoriasis Center, Department of Dermatology, Venereology and Allergy; University Medical Center Schleswig-Holstein; Campus Kiel Germany
3. Clinic for Dermatology and Venereology; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
4. Private Practice; Osnabrück Germany
5. Comprehensive Center for Inflammation Medicine; University Medical Center Schleswig-Holstein, Campus Lübeck; University of Lübeck; Lübeck Germany
6. Private Practice; Hamburg Germany
7. Private Practice; Bochum Germany
8. Dermatologikum Hamburg; Germany