1 Departments of Dermatology, Venereology, Allergology and Immunology, Staedtisches Klinikum Dessau, Brandenburg Medical School Theodor Fontane, Dessau, Germany.
2 European Hidradenitis Suppurativa Foundation, Dessau, Germany.
3 4th Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
4 Department of Dermatology, Roskilde and Health Sciences Faculty, University of Copenhagen, Copenhagen, Denmark.
5 2nd Department of Dermatology and Venereology, "Attikon" General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
6 Department of Dermatology, Erasmus University Medical Center, Rotterdam, Netherlands.
7 Department of Dermatology, Nordland Hospital Trust, Bodø, Norway.