1. National Allergy Research Centre, Department of Dermatology and Allergy, Herlev and Gentofte Hospital, University of Copenhagen, DK-2900 Hellerup, Denmark
2. Department of Virus and Microbiological Special Diagnostics, Statens Serum Institute, DK-2300 Copenhagen, Denmark
3. Department of Dermatology and Allergy, Copenhagen University Hospital—Herlev and Gentofte, DK-2900 Herlev, Denmark
4. Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2900 Hellerup, Denmark