1. Department of Dermatology, Venereology and AllergologyUniversity Medical Center Göttingen Göttingen Germany
2. Lower Saxony Institute of Occupational DermatologyUniversity Medical Center Göttingen Göttingen Germany
3. Lower Saxony Institute of Occupational DermatologyUniversity of Osnabrück Osnabrück Germany
4. Department of Dermatology, Environmental Medicine and Health TheoryUniversity of Osnabrück Osnabrück Germany
5. Institute for Interdisciplinary Dermatologic Prevention and Rehabilitation (iDerm), University of Osnabrück Osnabrück Germany
6. Department of Dermatology, Allergology and VenereologyUniversity Hospital Schleswig‐Holstein Kiel Germany
7. Department of Epidemiology and Preventive MedicineUniversity of Regensburg Regensburg Germany
8. Laboratory for Analytical Chemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and BiotechnologyUniversity of Zagreb Zagreb Croatia
9. Information Network of Department of DermatologyGeorg August University Göttingen Germany
10. Coronel Institute of Occupational HealthAmsterdam University Medical Center Amsterdam The Netherlands