Diagnosis and Treatment of Local Allergic Rhinitis

Some patients with chronic rhinitis have a positive nasal allergen provocation test (NAPT) without systemic IgE sensitization by skin prick tests or serum allergen-specific IgE (sIgE). This novel concept is called local allergic rhinitis (LAR) and affects children and adults worldwide, but is underdiagnosed. LAR is not just the initial state of allergic rhinitis (AR), it is a unique form of chronic rhinitis that is neither classical AR nor non-AR. Many of the features of AR and LAR are similar, such as a positive NAPT, positive type 2 inflammatory markers, including the nasal discharge of sIgE, and a high incidence of asthma. A differential diagnosis of LAR needs to be considered in patients with symptoms suggestive of AR in the absence of systemic atopy, regardless of age. The diagnostic method for LAR relies on positive responses to single or multiple allergens in NAPT, the sensitivity, specificity, and reproducibility of which are high. The basophil activation test and measurement of IgE in nasal secretions also contribute to the diagnosis of LAR. Treatment for LAR is similar to that for AR and is supported by the efficacy and safety of allergen exposure avoidance, drug therapy, and allergen immunotherapy. This review discusses current knowledge on LAR.

Synaptic transmission molecules and their role in the pathogenesis of allergic rhinitis

Immune cells and molecules, as well as synaptic transmission molecules play a regulatory role in the communication pathways of the entire body when it is necessary to engage all body resources in the fight against infections or tumor cells wherever they appear. In potential allergy, the neuroimmune network controls allergen tolerance maintenance at both local and systemic levels.The review focuses on different neurotransmitters and our understanding of a balance and imbalance between the immune system and the nervous system in allergic inflammation, including allergic rhinitis. However, the pathogenesis of the two endotypes of rhinitis (conventional allergic rhinitis and local allergic rhinitis) and the impact of the neuroimmune network on it remain unresolved.

Efficacy and Safety of Subcutaneous Immunotherapy for Local Allergic Rhinitis: A Meta-Analysis of Randomized Controlled Trials

Background Subcutaneous immunotherapy (SCIT) has been used for treating local allergic rhinitis (LAR) patients. However, the clinical efficacy and safety were still questioned. Objective This study was designed to estimate the efficacy and safety of SCIT for treating LAR patients through meta-analysis. Methods We systemically searched MEDLINE, Cochrane Library, and Embase publications. Randomized, double-blind, clinical trials for the efficacy and safety of Allergen Immunotherapy (AIT) for LAR were included. A meta-analysis of 4 clinical endpoints (combined symptom and medication scores [CSMS], symptom scores [SS], medication scores [MS] and rhinoconjunctivitis quality of life questionnaire [RQLQ]) and adverse events (AEs)) was performed after bias and heterogeneity assessments. The immunologic response results were summarized. Results Four RCTs with 134 patients were included. Four studies for analyzing primary outcomes (CSMS, SS, MS) and AEs, three for RQLQ results. The results indicated an important significant difference between SCIT and placebo groups, list as follows: CSMS (SMD = −2.42, 95% CI: −3.60 to −1.25, P < .0001), SS (SMD = −2.08, 95% CI −3.68 to −0.48, P = .01), MS (SMD = −1.43, 95% CI: −2.65 to −0.21, P = 0.02), RQLQ (SMD = −0.70, 95% CI −1.29 to −0.12, P = .02), Local AEs (RR = 4.13, 95% CI 1.08 to 15.77, P = .04). For immunologic response, significantly increased serum sIgG4 levels and improvements of allergen tolerance was observed after SCIT. Conclusions Our meta-analysis suggests that SCIT has a significant effect on improving symptoms and reducing medicine consumption for LAR patients. Larger and multicenter clinical trials are needed to clarify the safety and long-term efficacy.

Allergen-specific immunotherapy for local allergic rhinitis: a systematic review and meta-analysis

Background: Local allergic rhinitis (LAR) is a phenotype of chronic rhinitis exhibiting a local Th2-driven inflammation without positive clinical markers of atopy. Immunomodulatory effects of allergen-specific immunotherapy (AIT) induce allergen-specific tolerance. However, AIT is not well-recognized as a treatment for LAR. Methodology: Systematic search on six electronic databases and registries was performed. Experimental and observational studies of AIT for LAR patients were retrieved. The primary outcomes were symptom score, medication score, combined symptom medication score, and disease-specific quality of life. Secondary outcomes were serum specific(s) IgG4, sIgE, and adverse events. Results: Four double-blind randomized controlled trials (156 patients) from two research units assessed the effects of subcutaneous immunotherapy (SCIT). Compared with placebo, SCIT showed significant reductions in symptom score, medication score, combined symptom medication score, disease-specific quality of life, and an increase in serum sIgG4. There was no significant change in serum sIgE. Likewise, two observational studies (one using SCIT and one using sublingual immunotherapy) improved post-therapeutic symptom score. No studies assessed the effects after discontinuation of treatment. AIT was safe without serious adverse events. Conclusion: AIT has beneficial effects and safe for LAR. Its effects are restricted to studies with short-term follow-up. AIT may be considered in LAR patients.

Diagnostic Tools in Allergic Rhinitis

Allergic mechanisms account for most cases of chronic rhinitis. This condition is associated with significant impairment of quality of life and high indirect costs. The identification of the allergic triggers of rhinitis has been historically based on the performance of atopy test [skin prick test (SPT) and serum allergen-specific (s)IgE]. Nevertheless, these tests only denote sensitization, and atopy and allergy represent two different phenomena. It is now clear that allergic phenotypes of rhinitis can exist in both atopic (allergic rhinitis, AR) and non-atopic (local allergic rhinitis, LAR) individuals. Moreover, both allergic phenotypes can coexist in the same rhinitis patient (dual allergic rhinitis, DAR). Therefore, a diagnostic approach merely based on atopy tests is associated with a significant rate of misdiagnosis. The confirmation of the allergic etiology of rhinitis requires the performance of in vivo test like the nasal allergen challenge (NAC). NAC is mandatory for the diagnosis of LAR and DAR, and helps decide the best management approach in difficult cases of AR. Nevertheless, NAC is a laborious technique requiring human and technical resources. The basophil activation test (BAT) is a patient-friendly technique that has shown promising results for LAR and DAR diagnosis. In this review, the diagnostic usefulness for chronic rhinitis of SPT, NAC, olfactory tests, serum sIgE, BAT and the quantification of inflammatory mediators in nasal samples will be discussed. The accurate performance of an etiologic diagnosis of rhinitis patients will favor the prescription of specific therapies with disease-modifying potential like allergen immunotherapy.

Current Update of Local Allergic Rhinitis

Local allergic rhinitis (LAR) is a localized nasal allergic response in the absence of systemic atopy. The symptoms, duration, severity, and comorbidities of LAR are similar to those of allergic rhinitis. Although pathophysiology of LAR is not fully understood, in some patients specific IgE can be demonstrated in the nasal secretions. The diagnosis currently relies on the positive results of nasal provocation test. Nasal provocation test has shown high sensitivity and specificity with safety, and is considered as the gold standard. LAR patients benefit from the same therapeutic strategies as allergic rhinitis patients, including the avoidance of allergen exposure and the pharmacotherapy. Effectiveness and safety of allergen immunotherapy open a window of treatment opportunity in LAR. This review provides a current update on LAR.

Differentiating the endotypes in allergic rhinitis

Aim. The aim of the study was to differentiate the endotypes in allergic rhinitis by key allergy markers in a mixed group of patients.Material and Methods. The study comprised a total of 48 patients, men and women, aged 18-60 years suffering from three endotypes of allergic rhinitis including the classic, local, and dual allergic rhinitis. The standard diagnostics of allergic rhinitis included taking a history of allergies, family history of allergic disease, video rhinoscopy, serum total IgE level assessment, allergy skin tests to house dust mite and pollen allergens, and study of eosinophilic inflammation parameters (eosinophil cationic protein, interleukin-5 (IL5), and eosinophil counts in blood and nasal secretion).Results. Based on total IgE level, the general group of patients was divided to two subgroups: subgroup 1 comprised patients with high IgE level (n = 22); subgroup 2 comprised patients with low IgE level (n = 26). Most of patients in these groups had contradictory results of allergy skin tests i.e. positive allergy skin test results in case of high IgE level (group 1) and vice versa. Cluster analysis-based exminations of general group allowed to categorize three subgroups of patients: patients with classic allergic rhinitis (n = 22), local allergic rhinitis (n = 22), and dual allergic rhinitis (n = 4). Besides, an increased rate of anxiety disorder was found in patients with local allergic rhinitis (p < 0.001).Conclusion. The obtained data showed promise for a new research trend in studying allergic rhinitis endotypes, namely: investigation of neuroimmune relationships in allergic tolerance disruption in the presence of this pathology.

Local Respiratory Allergy: From Rhinitis Phenotype to Disease Spectrum

Local respiratory allergy (LRA) is defined by the negativity of atopy tests, a clinical history suggestive of airway allergy and a positive response to the nasal and/or bronchial allergen challenge. The clinical spectrum of LRA is comprised of three conditions: local allergic rhinitis (LAR) and local allergic asthma in non-atopic patients, and dual allergic rhinitis (coexistence of allergic rhinitis and LAR) in atopic individuals. LRA is an independent disease phenotype not progressing to atopy over time, but naturally evolving to the clinical worsening and the onset of comorbidities. Published data suggests that LRA is mediated through the mucosal synthesis of allergen-specific (s)IgE, which binds to FcϵRI on resident mast cells, and in &gt;50% of cases traffics to the blood stream to sensitize circulating basophils. To date, 4 clinical trials have demonstrated the capacity of allergen immunotherapy (AIT) to decrease nasal, conjunctival and bronchial symptoms, to improve quality of life, to increase the threshold dose of allergen eliciting respiratory symptoms, and to induce serum sIgG4 in LRA individuals. Collectively, these data indicate that local allergy is a relevant disease mechanisms in both atopic and non-atopic patients with airway diseases.