1. Department of Dermatology Ghent University Hospital Ghent Belgium
2. Department of Dermatology AZ Delta Torhout Belgium
3. Department of Dermatology Clinic Dr. med. Rotterdam Gelsenkirchen Germany
4. Department of Dermatology Universitary Clinic of Essen Essen Germany
5. Department of Dermatology Institute for pigment disorders and Infection & Immunity Institute Amsterdam UMC Amsterdam The Netherlands