1. Pediatric Epidemiology, Department of Pediatrics, Medical Faculty Leipzig University Leipzig Germany
2. Institute of Epidemiology and Medical Biometry Ulm University Ulm Germany
3. Department of Dermatology and Allergology University Medical Center Ulm Ulm Germany
4. Department of Dermatology, Venereology, and Allergology University Hospital Schleswig‐Holstein Kiel Germany
5. Division of Clinical Epidemiology and Aging Research German Cancer Research Center Heidelberg Germany
6. German Center of Child and Youth Health (DZKJ) Leipzig Germany