1. Service of Allergy, Fundación Jiménez Díaz, Madrid, CIBERES, Instituto Carlos III, Department of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
2. Dermatology Unit, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
3. Service of Dermatology, Hospital Universitario Puerto Real, University of Cádiz, Cádiz, Spain
4. Service of Allergy, Hospital Universitario 12 de Octubre, Madrid, Spain
5. Service of Allergy, Hospital Universitario Cruces, Barakaldo, Vizcaya, Spain
6. Service of Dermatology, Hospital Universitari Son Espases, Palma, Spain
7. Service of Dermatology, Hospital Universitario 12 de Octubre, Madrid, Spain
8. Service of Dermatology, Hospital General Universitario de Alicante, Alicante, Spain
9. Section of Allergy, Hospital Clinic i Provincial de Barcelona, IDIBAPS, Universitat de Barcelona, Barcelona, Spain