CONCLUSIONS.
AR is a common disease in childhood in industrialized countries and it
has a major impact on quality of life and health care resources.
Improving the understanding of the pathophysiology of allergy and
relationship with its comorbidities is important to correctly develop
timed preventive measures as well as perform adequate monitoring and
treatment of children with rhinitis. The correct management of allergic
diseases can, in fact, decrease the inflammatory response and most
likely lead to better control of comorbidities.
Our qualitative analyses demonstrated that there is clear evidence from
the lab of a link between allergy and an overall impairment of
mechanical and immunological defense function of nasal mucosa against
viruses. Clinical studies support the hypothesis of a positive
association between allergy and viral acute rhinosinusitis/URTI, and
only low-quality retrospective studies reached conflicting results.
Proof of this is the existence of high-quality investigations showing
that anti-allergy treatments may significantly decrease the number and
severity of URTI including common colds. We did not find any articles
investigating specifically the link between allergy and upper airway
involvement by the new coronavirus in children.
Current experimental and clinical experience does not support an
etiological link between allergy and post viral rhinosinusitis, ABRS and
RARS. At the moment anti-allergy treatments are not advised in these
phenotypes even though well design high quality studies are required to
improve our knowledge in this field reaching firm conclusions.
Despite the growing knowledge related to allergy and chronic
rhinosinusitis in children, it is not yet clear whether AR may promote
CRS or if they only share a common pathway of pathogenesis. Even if AR
has been positively associated with CRS in several experimental and
clinical studies in children, conflicting results have also been
reported, probably because of discrepancies in definitions of the
disease processes for both CRS and AR and allergy testing methodologies.
Researchers have used a variety of techniques to document the presence
of sinusitis, such as patient surveys, radiography, CT scan, rhinoscopy,
and routine physical examination, and, therefore, the results may not
reflect homogeneous populations. In addition, experimental studies and
radiological assessment are often prevented by local ethical committees
in the pediatric population, for comprehensible reasons. Furthermore,
the evidence supports the hypothesis that CRS in children over the age
of 13 seems to be more frequently associated with eosinophilic
inflammation, whereas in younger patients with CRS neutrophilic
inflammation is observed more often(10,11). We did not
find investigations analyzing the impact of allergy on CRS based on age,
and we believe that more data from large epidemiological studies using
explicit criteria is needed.
Although there is no proof of causation, several studies suggested that
evaluation of underlying allergies in CRS children is equally
recommended, at least to exclude allergy as a concomitant disease and to
improve control of symptoms avoiding exposure to known allergens and
promoting allergy therapies. Future studies are needed to confirm that
anti-allergy treatment may improve outcomes of endoscopic sinus surgery
for CRS in children.
We summarized in a practical algorithm our conclusions per each
phenotypes of rhinosinusitis in order to elucidate when prompt accurate
diagnosis and treatment of allergy is recommended (Figure 2).