The Loss of Smell in Persistent Allergic Rhinitis Is Improved by Levocetirizine due to Reduction of Nasal Inflammation but Not Nasal Congestion (the CIRANO Study)

<i>Background:</i> Persistent allergic rhinitis (PER) has a moderate impact on the sense of smell, but no controlled study has reported the effect of antihistamines on the loss of smell in patients with PER. <i>Methods:</i> Patients with PER and subjective loss of the sense of smell (n = 27) were included in this pilot randomised, double-blind, placebo-controlled study. Nasal symptoms, nasal endoscopy, skin prick test,...