1. National Allergy Research Centre, Department of Dermatology and AllergyCopenhagen University Hospital Herlev‐Gentofte Hellerup Denmark
2. Department of Occupational DermatologySahlgrenska University Hospital Gothenburg Sweden
3. Department of Dermatology and VenereologyInstitute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
4. Department of Chemistry and Molecular Biology, Dermatochemistry and Skin AllergyUniversity of Gothenburg Gothenburg Sweden
5. Department of Analytical Chemistry and Environmental ScienceStockholm University Stockholm Sweden
6. Department of Dermatology and AllergyCopenhagen University Hospital Herlev‐Gentofte Hellerup Denmark