1 Department of Otorhinolaryngology, Head and Neck Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
2 Center for Rhinology and Allergology, Wiesbaden, Germany.
3 Respiratory and Allergic Disease Division, Department of Paediatrics, Medical University of Graz, Graz, Austria.