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Wise et al.

Page 151

Allergic rhinitis and chronic rhinosinusitis with nasal polyposis— The pathogenesis of CRSwNP is strongly associated with Th2-mediated inflammation. 1 Additionally, nasal polyps in CRSwNP have high levels of tissue eosinophilia, as well as mast cells and basophils. 1 AR follows a similar inflammatory pathway and this suggests there may be a pathophysiologic similarity between CRSwNP and AR. Wilson et al. 1854 examined the association between allergic disease and CRSwNP. Again, the evidence was conflicting. Ten studies supported an association while 7 did not. One study had equivocal findings. 1854 Since this review, Li et al. 1855 examined the association between atopy and CRSwNP and concluded that there was no correlation between atopic status and disease severity. They did note that atopy-positive patients were younger than atopy-negative patients. 1855 Despite some overlapping pathophysiologic features between allergic disease and CRSwNP, conflicting evidence exists and there is no clear association between AR and CRSwNP. Allergy testing is once again an option in CRSwNP patients based on the theoretical benefit of identifying and treating comorbid allergic disease 1,1854 (Table X.B-4). • Aggregate Grade of Evidence: D (Level 2b: 1 study; Level 3a: 1 study; Level 3b: 15 studies; Level 4: 4 studies; conflicting evidence; Table X.B-4). Adapted from Wilson et al. 1854 In summary, AR has a moderate level of evidence supporting an association with ARS (Level C). Regarding RARS, CRSsNP and CRSwNP, the preponderance of evidence does not support an association, though the evidence is highly conflicting. The available literature is also limited as it often assumes patients who test positive on allergy testing have nasal allergic disease and may not differentiate between systemic allergy and nasal allergy. Further study is needed to determine the association between AR and rhinosinusitis, as well as the impact treating 1 process has on the progression of the other. However, the diagnosis and treatment of comorbid allergic disease is an option in rhinosinusitis patients balancing the cost and low evidence with the low risk of allergic rhinosinusitis treatment and the theoretical benefits of reducing allergic sinonasal inflammation. 1 Although the burden of illness (impaired QOL) associated with allergic conjunctivitis (AC) is well established, this condition is often under recognized and consequently undertreated except when it is most severe. 1882 Its frequent association with AR contributes to the substantial burden associated with AR. Although this association is well recognized clinically, its extent remains poorly defined due to methodologic differences and deficiencies of the studies which have examined this association in the literature. Further compounding this problem is the phenotypic diversity of both AR and AC, and the observation that very few studies have adequately characterized the phenotypes of their study populations. Additionally, many epidemiologic studies are limited by being based solely on questionnaire results rather than on objective clinical evidence of allergic sensitization. The largest data source regarding the AR-AC association derives from the ISAAC study, a worldwide study established in 1991 with the aim of investigating the epidemiology and etiology of asthma, rhinitis, and atopic dermatitis in each country, using standard methodology including questionnaire and SPT. ISAAC has reported the prevalence of AC

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X.C. Conjunctivitis

Int Forum Allergy Rhinol . Author manuscript; available in PMC 2020 June 10.