1. Department of Dermatology; University of Witten/Herdecke and Klinikum Dortmund (formerly); 44137 Dortmund Germany
2. Allergy Unit, Department of Dermatology; University Hospital Erlangen; 91054 Erlangen Germany
3. Department of Medical Informatics, Biometry and Epidemiology; Friedrich-Alexander University Erlangen-Nürnberg; 91054 Erlangen Germany