1. Service de Dermatologie Centre Hospitalier Universitaire de Saint‐Etienne Saint‐Priest‐en‐Jarez France
2. Laboratory of Tribology and System Dynamics (LTDS), UMR 5513 CNRS, ECL‐ENISE, Ecole Centrale de Lyon University of Lyon Ecully France
3. Groupe D'Imagerie Cutanée Non Invasive de la Societe fRncaise de Dermatologie GCNI Paris France
4. Dermatology Unit, Department of Medical, Surgical and Neurosciences University of Siena Siena Italy