1. Department of Dermatology; University of Rome Tor Vergata; Italy
2. Department of Dermatology; Radboud University Medical Centre; Nijmegen the Netherlands
3. Radboud University Nijmegen; the Netherlands
4. Department of Dermatology; Ghent University Hospital; Ghent Belgium
5. Dermatology Unit; Azienda Ospedaliera San Donato; Milan Italy
6. Dermatology Unit, Department of Biomedical Sciences; Humanitas University; Milan Italy
7. Skin Pathology Laboratory; Istituto Clinico Humanitas; Milan Italy