1. Institute of Epidemiology, GSF-National Research Center for Environment and Health, Neuherberg, Germany
2. Dr von Haunersches Kinderspital, Ludwig-Maximilians Universität, Munich, Germany
3. Department of Pediatrics, Technical University of Munich, Munich, Germany
4. Medical Practice for Pediatrics, Bad Honnef, Germany
5. Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany
6. Municipal Hospital “St Georg,” Teaching Hospital of the University of Leipzig, Children's Hospital, Leipzig, Germany
7. Department of Pediatrics, University of Leipzig, Leipzig, Germany
8. Institut fuer Medizinische Umweltforschung, Institut für Umweltmedizinische Forschung, Düsseldorf, Germany
9. Department of Human Exposure Research and Epidemiology, Umweltforschungzentrum Halle/Leipzig Leipzig-Halle, and Department of Environmental Medicine and Environmental Hygiene, Faculty of Medicine, University of Leipzig, Leipzig, Germany
10. Division of Environmental Dermatology and Allergy GSF/Technische Universitaet Muenchen, Zentrum fuer Allergie und Umweltmedizin, Centre for Allergy and Environment, Technical University, Munich Germany
11. Institute of Medical Data Management, Biometrics and Epidemiology, Ludwig Maximilians University, Munich, Germany