Dr. Wallach is a graduate of University of Paris Faculty of Medicine. He was Senior Lecturer in the Departments of Dermatology of Hôpital Saint-Louis and Hôpital Tarnier in Paris, France. In addition to membership in the French Society of Dermatology, the American Academy of Dermatology, and the Society for Investigative Dermatology, Dr. Wallach founded and chaired the French and the European societies for the history of dermatology. His interests include medical dermatology, neonatal dermatology, and the history of dermatology. Dr. Vignon-Pennamen is a dermatopathologist working in the Hôpital Saint-Louis in Paris and a specialist in managing complex inflammatory skin conditions. Dr. Marzano is Professor of Dermatology at the University of Milan and works in the Dermatology Unit of the Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico in Milan, Italy. Professor Marzano is a world-known leader in dermatology and in immuno-dermatology, and he is currently the Chairman of the very active Italian Group of Immunodermatology. He described clinical entities inside the neutrophilic dermatoses’spectrum, such as the aseptic pustulosis of the folds and the PAPASH syndrome, and published many studies on the pathophysiology of neutrophilic dermatoses.