1. Department of Dermatology and Allergy; Allergie-Centrum-Charité; Charité - Universitatsmedizin Berlin; Berlin Germany
2. Clinic of Dermatology; University Hospital and Faculty of Medicine; University of Coimbra; Coimbra Portugal
3. Division of Allergy and Clinical Immunology; St. Michael's Hospital and University of Toronto; Toronto ON Canada
4. Allergy and Clinical Immunology Department; Centro Médico-Docente La Trinidad; Caracas Venezuela