1. Department of Dermatology and Venereology University of Cologne Cologne Germany
2. Department of Dermatology Venereology and Allergology HELIOS St. Elisabeth Hospital Oberhausen University of Witten‐Herdecke Oberhausen Germany
3. Department of Dermatology Allergology und Dermatosurgery HELIOS University Hospital Wuppertal University of Witten‐Herdecke Wuppertal Germany
4. Department of Dermatology and Venereology HELIOS Klinikum Duisburg Duisburg Germany
5. Institute of Medical Statistics and Computational Biology Faculty of Medicine and University Hospital Cologne University of Cologne Cologne Germany
6. Department of Dermatology and Venereology HELIOS Klinikum Krefeld Krefeld Germany
7. Institute of Pathology Mülheim an der Ruhr Germany