xRead - Nasal Obstruction (September 2024) Full Articles

20426984, 2021, 3, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/alr.22741 by Stanford University, Wiley Online Library on [01/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

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International consensus statement on rhinosinusitis

indicates that the heterogeneous pattern in CRSsNP may be geographically dependent. 54 US-based studies show a higher frequency of type 2 inflammation than type 1 in CRSsNP 61,565,566 consistent with findings in Europe. 54 In contrast CRSsNP patient from China were found to be type 1 predominant 54 while in Korea a mixed type 1/type 3 pat tern was found with the type 3 response appearing to be the dominant inflammatory pattern. 567 Overall this sug gests that CRSsNP may be a spectrum of disease mecha nisms with genetic, immunologic and environmental fac tors likely playing a role. Although allergic inflammation is characteristic of type 2 inflammation, there are no controlled studies on the role of allergy in the pathophysiology of CRSsNP. A pos tulated mechanism by which allergy predisposes individ uals to CRS is allergen-induced inflammation of the nasal mucosa leading to ostial obstruction and creating an envi ronment of persistent inflammation. While many studies have investigated the relationship between allergy and RS, few have done so in a pure CRSsNP population. Further more, there is a paucity of controlled studies examining the role of allergy in the pathophysiology of CRSsNP and existing epidemiologic studies use varying definitions of atopy/allergy with some using evidence of sensitization only (via skin testing or specific IgE) and others using sen sitization with concomitant clinical symptoms to define allergic patients. Associations based on these epidemio logic studies are conflicting and difficult to interpret. In 2014, Wilson et al. reviewed the role of allergy in CRSwNP and CRSsNP. 568 They considered only studies that delineated CRS into CRSsNP or CRSwNP subtypes. In both CRSsNP and CRSwNP, they found the aggregate LOE linking allergy to these forms of CRS to be level D due to conflicting prevalence data, complemented by expert opin ion and reasoning from first principles. In CRSsNP specif ically, they found 9 epidemiologic studies that addressed the role of allergy. Four of these studies supported an asso ciation, while 5 did not. They concluded that allergy testing should be considered an option in CRSwNP and CRSsNP patients, inasmuch as there was a theoretical benefit of finding inflammatory triggers, there is little harm, and the low aggregate level of evidence did not support a strong recommendation either for or against this practice. Since then Benjamin et al. found the presence of AR in CRSsNP correlated to more severe sinus disease radiographically compared to nonatopic CRSsNP patients. 185 A cross sec tional case control study in Europe found higher rates of allergy as assessed by medical history and confirmed by skin testing in patients with CRSsNP compared with ref erence controls though no significant differences in rates of self reported AR or asthma was found. 195 Despite the association of AR and CRS, the role of IT in CRS remains unclear. A review of CRS patients under

going IT by DeYoung included 7 studies which suggested IT improved sinus related outcomes. 569 However. given the small quantity and quality of the studies it was concluded there was weak evidence to support the use of IT an adjunc tive treatment in CRS and no studies to date have examined its role specifically in CRSsNP.

Allergy as a Contributing Factor for CRSsNP Aggregate Grade of Evidence: D (Level 1: 2 stud ies; level 2: 6 studies; level 4: 1 study. Conflicting evidence; Table IX-3). Benefit: Management theoretically reduces trig gers and could potentially modify symptoms of AR associated with CRS. Robust data on benefits are lacking. Harm: Mild local irritation associated with testing and immunotherapy and mild sedation seen with some antihistamine drugs. Severe complications are rare (see Table II-1). Cost: Moderate direct costs for testing and treat ment; some tests and therapies require significant patient time (eg, office-administered skin testing and subcutaneous immunotherapy). Benefits-Harm Assessment: Preponderance of benefit over harm has not been demonstrated for avoidance or immunotherapy. Benefits are largely theoretical and should be balanced against the significant cost of testing for allergies and instituting avoidance measures. Value Judgments: None. Policy Level: Option. Intervention: Allergy testing and treatment are an option in CRSsNP. IX.C.2 Contributing Factors for CRSsNP: Biofilms Many organisms in the sinonasal tract have the ability to form a biofilm, which is a community of bacteria or fungi that surrounds itself with a protective extracellu lar matrix. 570 Using “quorum sensing” molecules, bac teria communicate density status and begin to form a biofilm once an appropriate microbe concentration has been reached. 571 The protection of the biofilm renders the bacteria or fungus more resistant to external insults, including host defenses. The organisms themselves also undergo a phenotypic change 572 to require less oxygen and