1 Department of Dermatology, Center for Chronic Pruritus, University Hospital Münster, Münster, Germany.
2 Division of Occupational Dermatology, Department of Dermatology, University of Heidelberg, Heidelberg, Germany.
3 Department of Dermatology, Oslo University Hospital, University of Oslo, Oslo, Norway.
4 Department of Dermatology and Venereology, Lund University, Skane University Hospital, Lund, Sweden.
5 Department of Dermatology, Medical University of Graz, Graz, Austria.
6 Catholic University of the Sacred Heart, Rome, Italy.
7 Department of Dermatology, Aydın Adnan Menderes University, Aydın, Turkey.
8 Department of Dermatology, University of Rzeszów, Rzeszów, Poland.
9 Department of Dermatovenereology and Cosmetology, Central State Medical Academy of Department of Presidential Affairs, Moscow, Russia.
10 Medical Research and Educational Center, Lomonosov Moscow State University, Moscow, Russia.
11 Moscow Scientific and Practical Center of Dermatovenerology and Cosmetology, Moscow, Russia.
12 Institute of Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
13 Allergology and Immunology, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Berlin, Germany.
14 Department of Dermatology, Kantonsspital Aarau, Aarau, Switzerland.
15 Department of Dermatology, University Hospital of Brest, Brest, France.
16 Department of Dermatology, Sant Pau Hospital, Barcelona, Spain.
17 Department of Dermatology, University Hospital and Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
18 Department of Dermatology, Venereology and Allergology, Wroclaw Medical University, Wroclaw, Poland.
19 Competence Center for Healthcare Research in Dermatology (CVderm), Institute for Healthcare Research in Dermatology and Nursing (IVDP), University Hospital of Hamburg-Eppendorf, Hamburg, Germany.
20 Department of Dermatology and Allergy, Technical University of Munich, School of Medicine, Munich, Germany.