1.2 Allergy and post-viral acute rhinosinusitis and acute bacterial rhinosinusitis (ABRS) in children.
In the articles reviewed we did not find manuscript in which authors distinguished between post viral ARS and ABRS. Authors focused the attention in the particular on the risks of bacterial superinfection. Recent evidence suggests in fact that damage or disruption of mucociliary function due to viral infection is probably a major cause of super- or secondary bacterial infection. Allergy is a condition that potentially can exacerbate an inflammatory sino-nasal response, although very limited data are available to confirm this hypothesis.(28) Based on paucity and heterogeneity of the studies it was not possible to perform a qualitative analysis linking allergy to ABRS or to post viral ARS(7) for this reason we report by a narrative description available data.
Lin et al.(29) demonstrated that the prevalence of colonization by methicillin-resistant S. aureus was higher in atopic children than healthy ones and that atopic children were more likely to develop ARS than nonatopic ones. Interestingly, other authors(30) observed that AR was highly prevalent in orbital ARS complications in children and, specifically, it was found in 64.3% of children with pre-septal cellulitis, in 25% with periostitis, and in 76.5% with subperiosteal abscess. Furthermore, the prevalence of AR was significantly higher in patients presenting in pollen season from February to August than in patients presenting between September and January. The authors suggested that allergy may be a cofactor in the pathogenesis of orbital complication of ARS. In addition, Alho et al.(31) observed that subjects with allergic IgE-mediated rhinitis had more severe paranasal sinus changes in CT scans than non-allergic subjects during viral colds. The authors suggested that these changes were signs of more severely impaired sinus function, increasing the risk of bacterial sinusitis.
Shi-Wei Lin et al.(32) recently evaluated the risk of incident acute rhinosinusitis among children with allergic rhinitis, using a nationwide, population-based health claims research database and including a large number of patients. The authors observed that the risk of acute rhinosinusitis was significantly higher in pediatric patients with allergic rhinitis compared to those without the condition (adjusted hazard ratio = 3.03, 95% confidence interval = 2.89–3.18). Caution is advised when interpreting the findings of the authors due to limitations of the study: retrospective design, diagnosis of ARS based on clinical history (authors could not confirm bacterial etiology of sinusitis).
On the other hand, Leo et al.(33) demonstrated that children with grass pollen induced rhinitis during exposure to pollen had an incidence of endoscopically confirmed ARS comparable to non-allergic children; they consequently suggested that AR was a negligible risk factor for ARS and that the most common risk factor was instead a previous acute viral infection. Accordingly, EPOS 2020 concluded that there appears to be small evidence to support the presence of AR as a risk factor for developing ARS in children, recognizing a central role for previous viral infection.