1 Department of Allergy, Consorci Sanitari de Terrassa, Barcelona, Spain.
2 Unidad Alergo-Rino, Centro Médico Teknon, Barcelona, Spain.
3 Rhinology Study Group of the Young-Otolaryngologists of the International Federations of Oto-rhino-laryngological Societies (YO-IFOS), Paris, France.
4 Otorhinolaryngology Department, Hospital Complex of Santiago de Compostela, Santiago de Compostela, Spain.