1. Department of Internal Medicine II, Helios Klinikum Krefeld, Krefeld, Germany
2. Department of Internal Medicine I, Helios Klinikum Krefeld, Krefeld, Germany
3. Department of Dermatology and Venerology, University Hospital of the RWTH-Aachen, Aachen, Germany
4. Department of Dermatology and Venerology, Helios Klinikum Krefeld, Krefeld, Germany