1. Department of Dermatology Venereology and Allergology University Medical Center Göttingen Göttingen Germany
2. Institute of Pathology University Medical Center Göttingen Göttingen Germany
3. Lower Saxony Institute of Occupational Dermatology Germany
4. Kempf und Pfaltz Histologische Diagnostik Zürich Switzerland
5. Department of Dermatology University Hospital Zurich Zurich Switzerland