1. Department of Allergology and Occupational Dermatology; Dermatologikum Hamburg; 20354 Hamburg Germany
2. Department of Medical Informatics, Biometry and Epidemiology; University of Erlangen/Nürnberg; 91054 Erlangen Germany
3. Information Network of Departments of Dermatology; University of Göttingen; 37075 Göttingen Germany