1 Department of Dermatology and Allergy, University Hospital of Bonn, Bonn, Germany.
2 Institute for Medical Biometry, Informatics and Epidemiology, University Hospital of Bonn, Bonn, Germany.
3 Clinic of Internal Medicine III, Department of Oncology, Hematology, Rheumatology and Clinical Immunology, University Hospital of Bonn, Bonn, Germany.