INTRODUCTION
Allergic rhinitis (AR) is the most frequent chronic condition in childhood and adolescence, its prevalence varies from 1.5% up to 42%,1,2reaching 8% in 6–8-year-old children and up to 35% in 13–14 -year-old children, with a continuous increase in the developed world.3-5
Pediatric AR may have 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 the onset of the most frequent upper airway disorders in childrenand in particular of otitis media.It has been estimated that more than 75% of AR children develop concomitant conditions, including conjunctivitis, asthma, atopic dermatitis, upper respiratory tract infections (URTI), rhinosinusitis, adeno-tonsillitis, and otitis media, indicating that AR is not an isolated condition, but it is part of a systemic disease,even though conflicting results are frequently reached.6,7
AR is an inflammatory condition of the nasal mucosa provoked by environmental allergens interacting with immunoglobulin (Ig)E in sensitized subjects. Repeated exposure to allergens 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.8Consequently, it is not surprising that AR has been historically associated with comorbid upper airway diseases,among which otitis media.9
The association between AR and otitismedia isstill controversial. However, AR can cause swelling of nasal mucosa resulting in Eustachian tube (ET) dysfunction and subsequently otitis, in particular otitis media with effusion (OME) characterized by inflammation of the mucous membrane with fluid collection in the middle ear in the absence of acute infection. If untreated, OME may be complicated with hearing loss especially conductive type, poor school performance, behavioral problems, and reduced the quality of life.10
The aim of the present systematic review was toevaluate clinical and laboratory evidence,linking allergy to different phenotypes of otitis media in children. Allergy in these conditions may be evocated not only as risk, but also as a worsening factor. Poorly controlled AR might exacerbate comorbidities, whereas early diagnosis and its adequate treatment might improve these disorders having a substantial impact on the quality of life of children.8