1. Department of Coronel Institute of Occupational Health, Academic Medical Center; University of Amsterdam; 1105 AZ Amsterdam The Netherlands
2. Department of Dermatology-Allergology; VU University Medical Centre; 081 HV Amsterdam The Netherlands
3. Department of Dermatology and Allergy, National Allergy Research Centre; Herlev and Gentofte Hospital, University of Copenhagen; 2900 Hellerup Denmark
4. Department of Dermatology; Bispebjerg Hospital, University of Copenhagen; 2400 Copenhagen Denmark
5. Department of Dermatology; University of Lübeck; 23538 Lübeck Germany
6. Institute of Clinical Medicine; University of Oslo; 0318 Oslo Norway
7. Department of Dermatology; Oslo University Hospital; 0424 Oslo Norway
8. Department of Dermatology and Venerology; University Hospital Hamburg-Eppendorf; 20246 Hamburg Germany
9. Department of Dermatology, Environmental Medicine and Health Theory; University of Osnabrück; 49076 Osnabrück Germany
10. Department of Pharmacology and Toxicology; University of Lausanne; 1011 Lausanne Switzerland
11. Faculty of Food Technology and Biotechnology, Department of Chemistry and Biochemistry, Laboratory for Analytical Chemistry; University of Zagreb; 10000 Zagreb Croatia
12. University Department of Dermatovenereology; Clinical Hospital Zagreb and School of Medicine; 10000 Zagreb Croatia
13. Department of Pathology; Oslo University Hospital - Rikshospitalet; 0424 Oslo Norway
14. Centre for Immune Regulation; University of Oslo; 0424 Oslo Norway
15. Department of Dermatology and Allergology; Ludwig-Maximilians-University; 81377 München Germany
16. Department of Dermatology; Finnish Institute of Occupational Health; 00251 Helsinki Finland
17. Department of Chemicals and Product Safety; German Federal Institute for Risk Assessment; 10589 Berlin Germany
18. Laboratory for Immunology & Proteomics, Department of Dermatology and University Medical Centre Mannheim; University of Heidelberg; 68167 Mannheim Germany
19. Department of Dermatology, Allergy Research Group; Medical Centre - University of Freiburg; 79104 Freiburg Germany