1. Dermatology Unit Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico Milan Italy
2. Department of Pathophysiology and Transplantation University of Milan Milan Italy
3. Dermatology Clinic, Department of Medical Sciences University of Turin Turin Italy
4. Pediatric Dermatology Unit, Department of Clinical Sciences and Community Health Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milan Italy
5. Inter‐Hospital Pathology Division IRCCS MultiMedica Milan Italy