1. Information Network of Departments of Dermatology (IVDK) Institute at the University Medical Center Göttingen Göttingen Germany
2. Clinic of Dermatology and Allergology Cantonal Hospital St. Gallen St. Gallen Switzerland
3. Department of Dermatology, Venereology and Allergy University Medical Center Göttingen Göttingen Germany
4. Department of Dermatology University Hospital Zuerich Zuerich Germany
5. Center for Dermatology, Phlebology and Allergology Klinikum Stuttgart Stuttgart Germany
6. Department of Dermatology University Hospital Erlangen Erlangen Germany
7. Department of Dermatology, Venereology and Allergology St. Josef Hospital Ruhr University Bochum Bochum Germany