1. Department of Dermatology and VenereologyUniversity Medical Center FreiburgFaculty of MedicineUniversity of Freiburg Freiburg Germany
2. Department of DermatologyUniversity Medical Center Mainz Mainz Germany
3. Chair of Selfhelp Research, Comprehensive Cancer CenterUniversity Medical Center Freiburg, Medical Faculty, University Freiburg Freiburg Germany
4. Institute of Medical Biometry and StatisticsSection for Health Care Research and Rehabilitation ResearchUniversity Medical Center FreiburgUniversity of Freiburg Freiburg Germany
5. Group Practice for Psychotherapy and Psychooncology (PPPO), Stadtstraße 11 Freiburg Germany
6. Medical Center DortmundDepartment of Dermatology Dortmund Germany