1. Department of Medical Informatics, Biometry and Epidemiology; University of Erlangen/Nürnberg; 91054 Erlangen; Germany
2. Department of Dermato-Allergology, National Allergy Research Centre; Gentofte Hospital, University of Copenhagen; 2900 Hellerup; Denmark
3. Department of Chemistry and Molecular Biology; University of Gothenburg; 41137 Gothenburg; Sweden
4. Institute of Environmental Medicine; Karolinska Institutet; 17177 Stockholm; Sweden
5. Member of the SCCS; Copenhagen; Denmark
6. Liverpool John Moores University; Liverpool, Merseyside L3 5UZ; UK
7. Department of Cutaneous Allergy, St John's Institute of Dermatology; St Thomas' Hospital; London SE1 7EH; UK