Etiology, diagnosis and treatment of non-allergic rhinitis

This thesis focused on optimizing the diagnostic process and phenotyping in non-allergic rhinitis (NAR) and improving evidence-based treatment strategies. We demonstrated a similar hyper-reactivity prevalence rate in AR of 63.4% and in NAR of 66.9%. There were no differences between AR and NAR in terms of the number or type of hyper-reactivity stimuli. We confirmed that in most NAR patients there is a non-inflammatory endotype that is in need of other treatments than the conventional treatments like intranasal corticosteroids. After validation of the mini-Rhinoconjunctivitis Quality of Life questionnaire (mini-RQLQ) for use in NAR patients; we showed that QoL in NAR patients was significantly impaired. QoL in NAR was comparable with AR patients, with an exception for the mini-RQLQ subdomains ‘nasal complaints’ and ‘other complaints’ (i.e. tiredness etc.) for which NAR scored significantly higher (lower quality of life) compared to AR. The results of a Cochrane Review on intranasal steroids in 4452 NAR patients were presented. It is unclear whether intranasal corticosteroids reduce patient-reported disease severity in non-allergic rhinitis patients compared with placebo when measured at up to three months follow-up. The results of a Cochrane Review on intranasal capsaicin in 302 idiopathic NAR patients were presented. We recommend that capsaicin is a reasonable option to try under physician supervision. We showed that TRPV-antagonist has an appropriate safety profile and is capable of achieving a clinically relevant attenuation of capsaicin-provoked rhinitis symptoms in patients with NAR.