The study will include 2 visits separated by a maximum of 7 days. During the first visit, subjects' characteristics will be documented by a locally validated questionnaire. Allergy skin prick tests, spirometry, methacholine inhalation test and induced sputum will also be done. Asthma and rhinitis control will be evaluated by locally validated questionnaires, the Asthma Control Scoring System (ACSS) and the Rhinitis Control Scoring System (RCSS), respectively. Nasal peak inspiratory flow (NPIF) and oral peak expiratory flow (PEF) will also be recorded to obtain the nasal blockage index (NBI). On the second visit, nasal biopsies will be taken.