In the history of dermatology, we find an outstanding example of scientific collaboration of leading dermatologists leading to an international publication in the late 19th century. Published by Malcolm Morris, Paul Gerson Unna, Henry-Camille Chrysostome Leloir and Louis Adolphus Duhring, the "International Atlas of Rare Skin Diseases" focused on rare and unique cases in dermatology. This concept, extraordinary for the time of publication, was found to be very successful. Numerous first descriptions are found in the "International Atlas", such as porokeratosis of Mibelli, acanthosis nigricans of Pollitzer and Janovsky and also psorospermosis of Darier. The focus on distinct and detailed descriptions to promote progress in the science of dermatology sets this effort apart from all previous atlases. Therefore, the "International Atlas was one of the first steps leading to the modern concepts of scientific publication in dermatology.