1. Psoriasis Center at the Department of Dermatology; University Medical Center Schleswig-Holstein, Campus Kiel; Schittenhelmstraße 7 24105 Kiel Germany
2. Department of Dermatology, Venereology and Allergology; Wroclaw Medical University; Wroclaw Poland
3. Department of Dermatology; Medical University of Vienna; Vienna Austria
4. Department of Dermatology; Radboud University Medical Center; Nijmegen the Netherlands
5. Almirall S.A.; Barcelona Spain
6. Almirall Hermal; Reinbek Germany