1. Department of Allergy, Belén de la Hoz Caballer, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain
2. Department of Allergy, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Madrid, Spain
3. Department of Allergy, Hospital Clínico-Instituto de Investigación Sanitaria Aragón, Zaragoza, Spain
4. Section of Allergy, Hospital Sureste, Arganda, Madrid, Spain