1. Allergy and Immunology Unit; Fondazione ‘Salvatore Maugeri’; Institute of Care and Research; Scientific Institute of Pavia; Pavia; Italy
2. Division of Asthma and Allergy; Department of Chest Diseases; University Hospital Strasbourg; Strasbourg; France
3. Department of Medical Sciences ‘M. Aresu’; University of Cagliari; Cagliari; Italy
4. Department of Clinical and Experimental Medicine; Occupational Allergy Unit; Terni Hospital; University of Perugia; Perugia; Italy
5. Allergy and Clinical Immunology; University of Torino; ASO Mauriziano ‘Umberto I’; Torino; Italy
6. Department of Environmental Medicine and Public Health; University of Padova; Padova; Italy
7. Department of Allergy; Hospital La Paz-IdiPAZ and CIBER de Enfermedades Respiratorias CIBERES; Madrid; Spain
8. CIBER de Enfermedades Respiratorias; Ciberes and Department of Allergy; Fundación Jiménez Díaz; Madrid; Spain
9. Department of Clinical an Experimental Medicine; University of Perugia; Perugia; Italy
10. Department of Occupational Diseases; Nofer Institute of Occupational Medicine; Lodz; Poland
11. Section of Allergology; Department of Internal Medicine; Erasmus MC; Rotterdam; the Netherlands