Introduction
Antihistamines are among the most prescribed medicines in
otorhinolaryngology. This drug, which is excellent for rhinorrhea,
sneezing and itching, is often prescribed in combination with upper
respiratory infections such as colds and rhinitis. However, all drugs
have side effects. Antihistamine has been reported to promote otitis
media effusion,1 and antihistamines such as
dimetindene and azelastine have been shown to reduce ciliary beat
frequency significantly.2 This reduced ciliary beat
frequency has been shown to reduce mucociliary clearance, a major
defense mechanism in the respiratory mucosa, which ultimately lengthens
the time that microorganisms or pollutants can contact nasal mucosa and
increases the risk of sinusitis.3 In particular, the
reduced ciliary beat frequency is a characteristic of epithelial
metaplasia.3 In inflammatory conditions such as
sinusitis, not only is the ciliary beat frequency reduced but
mucociliary clearance function is decreased due to increased mucus
production.4
Nevertheless, there are still many clinicians who prescribe
antihistamines to patients with sinusitis.5 This is
because the ciliary beat frequency of patients who already have
sinusitis does not differ significantly from controls who do not have
sinusitis.6 Antihistamine is one of the top three
drugs prescribed by Asian pediatricians for the treatment of acute
rhinosinusitis.7 There is also a group who think that
antihistamine is helpful in rhinosinusitis with allergic
rhinitis.8 In some animal studies, it is also reported
that desloratadine inhibits allergic symptoms during allergen exposure
and reduces the augmented bacterial response.9
Taken together, antihistamine has a debatable effect in rhinosinusitis.
At this point, it is useful to examine the relationship between
antihistamine and the incidence of sinusitis based on large-cohort data
analysis.