1. Department of Medical Informatics, Biometry and Epidemiology; University of Erlangen/Nürnberg; 91054 Erlangen Germany
2. Department of Dermatology; VU University Medical Centre; 1081 HV Amsterdam The Netherlands
3. Department of Dermatology; Leeds Teaching Hospitals NHS Trust; LS7 4SA Leeds UK
4. Department of Dermato-Allergology; National Allergy Research Centre, Gentofte Hospital, University of Copenhagen; 2900 Hellerup Denmark