1. Université Paris Est Créteil (UPEC), Epidemiology in Dermatology and Evaluation of Therapeutics (EpiDermE) – EA 7379 Créteil France
2. Université de Paris, Research Center of Epidemiology and Statistics (CRESS‐U1153), INSERM Paris France
3. Hôpital Henri Mondor, Department of Dermatology 51 Avenue du Maréchal de Lattre de Tassigny Créteil 94000 France
4. Department of Dermatology Leiden, University Medical Centre Leiden the Netherlands
5. Unit for Population‐Based Dermatology Research, St John’s Institute of Dermatology, Guy’s and St Thomas’ NHS Foundation Trust and King’s College London London UK
6. Centre for Evidence Based Healthcare, School of Medicine, Clinical Sciences Building Phase 2 University of Nottingham Nottingham UK