1. Allergy Department; Royal Brompton & Harefield NHS Foundation Trust; London UK
2. National Heart & Lung Institute; Allergy & Clinical Immunology; Imperial College London; London UK
3. Verona University Hospital; Allergy Unit; Verona Italy
4. Verona University Hospital; Research Support Unit and Biostatistics; Verona
5. Department of Clinical and Experimental Medicine; University of Parma; Parma Italy