1. University of Groningen; University Medical Center Groningen; Groningen; the Netherlands
2. University Hospital of Montpellier; Montpellier; France
3. Swiss Institute of Allergy and Asthma Research (SIAF); University of Zürich; Davos; Switzerland
4. Hospital Vall d'Hebron; Barcelona; Spain
5. National & Kapodistrian University of Athens; Athens; Greece
6. Department of Dermatology; University Hospital Zürich; Zürich; Switzerland
7. Polyclinique de l'Ormeau; Tarbes; France