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Wise et al.

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• Aggregate Grade of Evidence: B (Level 1a: 1 study; Level 1b: 7 studies; Level 1c: 1 study; Level 2a: 1 study; Level 2b: 6 studies; Level 3a: 2 studies; Level 5: 1 study; Table VIII.F.3-1). VIII.F.4. Nasal specific IgE— AR is classically diagnosed by clinical history and with objective testing for confirmation, usually SPT or in vitro testing with serum sIgE. 301 In addition to positive systemic sIgE, AR patients have been shown to have sIgE in the nasal mucosa with evidence that class switching and antibody production occurs locally. 309-312,377,950,951 However, some patients have negative SPT or serum sIgE despite a clinical history suggestive of AR and meeting ARIA clinical criteria. 101,300 These patients are usually given the diagnoses of idiopathic rhinitis, vasomotor rhinitis, or NAR. 300 However, it has been demonstrated that many of these patients may have local allergic phenomena or LAR, a type of rhinitis characterized by the presence of a localized allergic response in the nasal tissues, with local production of sIgE and positive response to NPT without evidence of positive SPT or serum sIgE elevation. 107 LAR may affect more than 45% of patients otherwise categorized as NAR, 296,302,952 and up to 25% of patients referred to allergy clinics with suspected AR. 291 Like traditional AR patients, LAR can be classified as perennial or seasonal, and similar findings in the nasal mucosa have been reported in both of these populations. 300,301,953 It has even been suggested that some patients with occupational rhinitis may suffer from LAR. 107 Recent studies suggested a low rate of conversion of LAR to systemic AR. 296,302 The first 5 years of a long-term followup study performed in a cohort of 194 patients with LAR and 130 healthy controls found that patients with LAR of recent onset (less than 18 months from the diagnosis) had a similar conversion to systemic AR when compared to controls. 296 A small retrospective study performed in 19 patients with a long clinical history of LAR (greater than 7 years from the diagnosis) and negative SPT to a wide panel of allergens had a similar rate of development of systemic AR 302 compared with epidemiologic data of prevalence of atopy in a healthy population from that geographic area. 954 Upcoming data from the 10-year follow-up study should help to clarify the rate of a long-term conversion to systemic AR in patients with LAR. In fact, LAR can present later in life, and in elderly patients with rhinitis the incidence of LAR has been reportedly been as high as 21%. 304 grasses, pollens, and molds. 300,301,306,307,955 The production of nasal mast cells, eosinophils, and sIgE rapidly increases after allergen-specific stimulation in the nasal mucosa. 288,294,307 Different methods have been reported regarding how to best identify nasal sIgE including nasal lavage, cellulose disks, mucosal biopsy, and brushing (Table VIII.F.4). While there is no gold standard, most of these techniques appear to yield similar results in identifying nasal sIgE in LAR patients. Additionally, normative data for nasal sIgE levels and their clinical correlations have yet to be established and agreed upon, but work has begun in this area. 956 When evaluating a rhinitis patient, in the setting of negative systemic testing, the differentiation of LAR from NAR can provide important information for management. While both typically respond to pharmacologic treatment, identification of offending The diagnosis of LAR is confirmed by positive response to NPT, and evidence of sIgE in the nasal secretions. A variety of allergens have been tested in this fashion including dust mites,

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