Is chronic rhinosinusitis related to allergic rhinitis in adults and children? Applying epidemiological guidelines for causation

Abstract

The relationship between allergic rhinitis and chronic rhinosinusitis has been assessed in a number of observational and experimental studies. In this review, we attempt their synthesis and evaluation using the modified Bradford Hill guidelines for causation. Although there is no proof of causation, especially in the pediatric literature, an evaluation of underlying allergies is recommended at least as an initial measure of symptoms relief.Chronic inflammatory disorders of the upper airways are extremely prevalent and have a major impact on public health (1-5). Some review articles on chronic rhinosinusitis (CRS) have suggested that atopy predisposes to its development (6), because allergic rhinitis (AR) is a common coexisting disease in pediatric and adult patients with CRS (7).Despite the fact that acute and CRS have been shown to occur frequently in AR patients, a sound pathophysiologic mechanism has not been proven, and thus, the association between rhinosinusitis and AR remains controversial (8, 9). The hallmark of AR is an IgE-mediated (type I) hypersensitivity reaction to an inciting inhaled antigen (10) and, in some cases, an ingested food that causes a cross-reaction because of antigenic similarities between the inhalant and the food (11). On the other hand, the pathophysiology of CRS is more obscure. Although the clinical presentation and symptoms of CRSwNP and CRSsNP overlap, it appears that they are underlined by distinct pathophysiological mechanisms.For example, nasal polyps (NP) have significantly higher levels of eosinophil markers, while CRSsNP is characterized by a Th1 polarization with high levels of interferon-gamma (IFN-c) and transforming growth factor-beta (TGF-b). On the other hand, CRSwNP showed a Th2 polarization with high IL-5 and immunoglobulin (Ig) E concentration (12). One step further is to assess whether the Th2 phenotype in CRSwNP is the result of the atopic status, the presence of AR, or (allergic) asthma. We know that there are many parallels between NP and asthma (13). And even some specific gene polymorphisms present in CRS have also been found in asthma (14). Several reviews on the role of allergy in CRS, in both adults (11,15) and children (16), can be found in the recent English literature, where epidemiological and experimental studies are mentioned. However, a logical structure for investigating and defining causality in epidemiological studies, such as Bradford-Hill criteria for causation, has not been Allergy 69 (2014) 828-833

Impact of Allergy and Eosinophils on the Morbidity of Chronic Rhinosinusitis with Nasal Polyps in Northwest China

“…CRS is generally classified under the following 2 subtypes: CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP) [2]. Although CRSwNP and CRSsNP have the same clinical presentation and symptoms, it appears that they are characterized by distinct pathophysiological mechanisms [3]. CRSsNP shows Th1 polarization with high levels of interferon-γ (IFN-c) and transforming growth factor-β (TGF-b), whereas CRSwNP is characterized by Th2 polarization with high IL-5 and immunoglobulin E concentrations.…”

Aeroallergen sensitivities and development of chronic rhinosinusitis in 13 adults who initially had allergic rhinitis

“…It has been suggested that AR may be a predisposing factor for development of CRS . If this is the case, it is possible that the degree of atopy, as measured by the number of aeroallergen sensitivities, may be associated with the development of CRS in patients with AR.…”

“…Based on common comorbidity, immunologic mediators and symptomatology, there exist reported epidemiologic and pathophysiologic links between allergic rhinitis (AR) and chronic rhinosinusitis (CRS) . In addition, AR has previously been associated with individuals who develop CRS .…”

A Survey of Clinical Features of Allergic Rhinitis in Adults

“…Co-morbidities were more common in patients with moderate/severe AR, with the highest rate for conjunctivitis, which was present in 54% of subjects, defining the picture of rhinoconjunctivitis, which occurs very frequently in patients with AR [21]. According with the literature, the other 2 most common co-morbidities were asthma (~38%) and sinusitis (~14%) [22–26]. In treatment of AR, the most frequently used drugs were oral antihistamines (77%) and topical corticosteroids (61%), in accordance with the ARIA guidelines, which state the adequacy of these treatments based on the evidence from controlled trials [10,22].…”