1. Department of Dermatology; Tübingen University Hospital; Germany
2. Clinic and Polyclinic for Otolaryngology/Surgery; Bonn University Hospital; Germany
3. Department of Dermatology; Kiel University Hospital; Germany
4. Leipzig University Clinic for Radiotherapy and Radiooncology; Germany
5. Clinic and Polyclinic for Oral and Maxillofacial Surgery; Klinikum rechts der Isar; Munich Germany
6. Department of Dermatology, Venereology, and Allergology; Charité - Universitätsmedizin; Berlin Germany
7. Department of Dermatology and Allergology; Knappschaftskrankenhaus Recklinghausen; Germany
8. Department of Dermatology; Klinikum Kassel; Germany
9. Department of Dermatology; Mainz University Hospital; Germany