1. The Northwest London Hospitals NHS Foundation Trust London U.K.
2. Imperial College of Science, Technology and Medicine London U.K.
3. EA EpiDermE (Epidémiologie en Dermatologie et Evaluation des Thérapeutiques) UPEC‐Université Paris‐Est Créteil Service de Dermatologie Hôpital Henri Mondor Créteil 94010 France
4. Departments of Dermatology and Histopathology The Hillingdon Hospitals NHS Foundation Trust Pield Heath Road Uxbridge U.K.