1. Department of Dermatology and Allergy; Urticaria Center of Reference and Excellence (UCARE); Charité-Universitätsmedizin Berlin; Berlin Germany
2. Department of Dermatology; Urticaria Center of Reference and Excellence (UCARE); University Medical Center Mainz; Mainz RP Germany
3. Division of Allergy and Immunology; University of South Florida; Tampa FL USA
4. Division of Clinical Immunology and Allergy; Urticaria Center of Reference and Excellence (UCARE); University of Toronto; Toronto ON Canada