INTRODUCTION.
Allergic rhinitis (AR) in children has a significant impact on global quality of life, including school performance, sleep disorders, and emotional health(2). Furthermore, over the years many authors tried to correlate allergy with comorbidities and in particular to the onset of rhinosinusitis including common cold, even though conflicting results are frequently reached.
AR is a nasal mucosa inflammatory condition caused by environmental allergens interacting with immunoglobulin (Ig) E in sensitized subjects. Repeated exposure may lead to long-term changes in systemic and local inflammation, including up-regulation of nasal eosinophils and allergen-specific IgE, increased levels of adhesion molecules in airway mucosa and enhanced systemic response to allergen challenge(4). Consequently, it is not surprising that AR has been historically associated with comorbid upper airway diseases(5). Herein, we review clinical and laboratory evidence, linking allergy to rhinosinusitis in children. We aimed to investigate allergy not only as etiologic, but also as a worsening factor; in fact, poorly controlled AR might contribute to exacerbations and as such its adequate treatment might improve outcomes(6).