1. Department of Dermatology and Venereology University of Cologne Cologne Germany
2. Department of Dermatology University Medical Center Mainz Mainz Germany
3. Department of Dermatology, Venereology and Allergology University Hospital Würzburg Würzburg Germany
4. Department of Dermatology Helios Hospital Krefeld Krefeld Germany
5. Department of Dermatology Dortmund Hospital Dortmund Germany
6. Department of Dermatology, Venereology and Allergology HELIOS St Elisabeth Hospital Oberhausen University Witten/Herdecke Oberhausen Germany
7. Department of Dermatology University Hospital Basel Basel Switzerland
8. Department of Dermatology University Hospital Salzburg Paracelsus Private Medical University of Salzburg Salzburg Austria
9. Institute of Pathology Salzburg Austria
10. Department of Dermatology, Venereology and Allergology Ruhr‐University Bochum Bochum Germany