Nasal obstruction, also referred to as congestion, blockage or stuffiness, is a crucial symptom in
allergic rhinitis (AR) and may affect sleep as well as quality of life. Early- and late-phase-
allergic reactions both contribute to
nasal obstruction, although it primarily represents a major symptom in the chronic
allergic reaction. A complex network of inflammatory and neurogenic phenomena relates to chronic
nasal obstruction, including the subepithelial accumulation of inflammatory cells, particularly mast cells and eosinophils, and the release of
neuropeptides.
Nasal obstruction is a difficult-to-treat symptom.
Vasoconstrictors (
decongestants) and intranasal
corticosteroids, due to their anti-inflammatory properties, have mainly been used for relieving the nasal passages from the congested mucosa. However, there is accumulating evidence recently that the latest-generation potent
antihistamines have
decongestant properties in AR. This paper aims to review the pathophysiologic background of
nasal obstruction and the evidence for an
antihistamine,
levocetirizine, in relieving nasal congestion. A meta-analysis on the early and late effects of
levocetirizine on
nasal obstruction under artificial and natural
allergen exposure conditions is presented, demonstrating convincingly that
levocetirizine shows a consistent effect on
nasal obstruction as early as over the first 2 h and sustained over 6 weeks.