1 Pediatric Pneumology and Allergy Unit, Reina Sofía Children's University Hospital, Córdoba, Spain; Department of Pediatrics, University of Cordoba, Córdoba, Spain. Electronic address: jtorbo@yahoo.es.
2 Pediatric Pneumology and Allergy Unit, Dr. Peset University Hospital, Valencia, Spain; Department of Pediatrics, Obstetrics and Gynecology, University of Valencia, Valencia, Spain.