1. Dermatology Clinic Fondazione IRCCS Policlinico San Matteo Pavia Italy
2. Department of Clinical‐Surgical Diagnostic and Pediatric Sciences University of Pavia Pavia Italy
3. Current affiliation: Dermatology Unit ASST Papa Giovanni XXIII Hospital Bergamo Italy
4. Scientific Direction Clinical Epidemiology and Biometric Unit Fondazione IRCCS Policlinico San Matteo Pavia Italy
5. Laboratory of Immuno‐Allergology of Clinical Chemistry and Pediatric Clinic Fondazione IRCCS Policlinico San Matteo and University of Pavia Viale Camillo Golgi 19 Pavia 27100 Italy