Antihistamines
Antihistamines are available as oral, intranasal, and ocular
preparations. Oral first generation, sedating antihistamines are no
longer recommended for the treatment of pediatric rhinitis due to their
impaired safety profile often associated with cardiac arrhythmias,
drowsiness, confusion, vision, and mental disorders etc. Of importance,
a recent report using data from the World Health Organization (WHO)
database, showed that the use of certain antihistamines has been
strongly associated with severe and unexpected reactions, more so in
preschoolers, where off-label use is frequent [98].
Second generation antihistamines
present a significantly improved safety profile due to their high
H1-receptor selectivity, low brain permeability and longer duration of
action [99]. Recently, cardiac rhythm safety was documented for
certain 2nd generation antihistamines, such as
bilastine, cetirizine, levocetirizine, ebastine, fexofenadine,
loratadine, desloratadine, mizolastine and rupatadine, even in the case
of quadrupling the recommended standard dose [100]. Antihistamines,
act predominantly on neutrally mediated symptoms such as sneeze,
rhinorrhea, and nasal itch. They should be used continuously, rather
than no-demand in persistent rhinitis patients [93]. Topical/nasal
antihistamines have rapid onset of action and minimum side effects
[101]. In addition, azelastine has been shown to have mast
cell-stabilizing, anti-leukotriene, anti-inflammatory and
immunomodulatory effects [102].
Intranasal corticosteroids
(INCs)
INSc are the mainstay, particularly for moderate-to-severe allergic
rhinitis, due to their anti-inflammatory properties and significant
attenuation of late phase allergic reaction, thus acting on nasal
congestion [59, 103]. In respect to non-allergic rhinitis, a recent
Cochrane review showed that INCs use has only short term beneficial
effects on symptom severity, potentially depending on individual
phenotypic characteristics [104]. INCs have a rapid onset of action,
while the newer preparations such as mometasone furoate, fluticasone
furoate (FP) and fluticasone propionate present negligible systemic
absorption, thus they are mostly suitable for children [105].
On-demand use can be an efficacious alternative in children with
seasonal AR symptoms, especially in families with safety concerns on
daily CS use, in order to increase adherence [106]. Recently, an
ARIA-EAACI statement suggested that, based on current evidence, patients
with COVID-19 infection should not discontinue their INCS prescribed for
AR symptoms [107].
The recently formulated combination of azelastine and fluticasone
propionate (FP) has shown short and long term efficacy, with superiority
over FP both in speed of action and symptom relief, in children with AR
[108, 109]. Safety and tolerability have been documented in children
over 4-years of age, with minimal local adverse reactions such as
dysgeusia [110]. The combination has been granted approval for use
in children over 6 years of age by the U.S. Food and Drug Administration
[111].
Antagonists of leukotriene receptors (LTRA) block cysteinyl
leukotrienes receptors, which are important mediators of the
inflammatory response in both AR and asthma [112]. Several studies
have shown inferiority of LTRA compared to INCS and SGHA as therapeutic
choices in AR, while as of 03/04/2020 FDA required a boxed warning,
based on limited data reporting serious mental health side effects, thus
restricting montelukast use for AR [113].