1. Department of Dermatology Ghent University Hospital Gent Belgium
2. Department of Dermatology, Cliniques Universitaires Saint‐Luc Université Catholique de Louvain Brussels Belgium
3. Department of Dermatology AZ Delta Campus Rembert Torhout Torhout Belgium
4. Department of Immunology‐Allergology‐Rheumatology University of Antwerp and Antwerp University Hospital Antwerp Belgium
5. Department of Dermatology Universitair Ziekenhuis Brussel Brussels Belgium
6. Vrije Universiteit Brussel Brussels Belgium
7. Service Infectious Diseases and General Internal Medicine CHU Liège Liège Belgium
8. Department of Dermatology University Hospital Antwerp University of Antwerp Antwerp Belgium
9. Groepspraktijk Dermatologie Roeselare Roeselare Belgium
10. N.V. Novartis Pharma S.A. Vilvoorde Belgium
11. Laboratory of Clinical Immunology KU Leuven Department of Microbiology and Immunology Leuven Belgium