1. IVDP - Institute for Health Services Research in Dermatology and Nursing; University Medical Center Hamburg-Eppendorf; Hamburg Germany
2. Department of Dermatology and Venereology; Geneva University Hospital and Department of Pathology and Immunology; Medical Faculty of the University of Geneva; Switzerland
3. Department of Dermatology; University Hospital of Münster; Germany
4. Psoriasis Center, Department of Dermatology; Venereology and Allergology; University Hospital Schleswig-Holstein; Campus Kiel Germany
5. Dermatology Group Office am Tibarg; Hamburg Germany
6. Group Office for Dermatology and Allergology; Mönchengladbach Germany
7. Department of Dermatology; University Hospital Carl Gustav Carus; Dresden Germany
8. Dermatology Office Dr. Ralph von Kiedrowski; Selters/Westerwald Germany
9. Dermatologikum; Hamburg Germany