1. Dermatology Unit and Skin Bank Unit Department of Clinical, Surgical and Neuro‐sciences University of Siena Italy
2. Rheumatology Unit Department of Clinical, Surgical and Neuro‐sciences University of Siena Italy
3. Department of Pathology University Hospital of Saint‐Etienne Saint‐Etienne France
4. Department of Dermatology University Hospital of Saint‐Etienne Saint‐Etienne France