Nasal hyperreactivity in rhinitis: A diagnostic and therapeutic challenge.

Although nasal hyperreactivity (NHR) is a common feature in patients suffering from allergic and nonallergic rhinitis, it is widely neglected during history taking, underdiagnosed in the majority of patients with rhinitis and rhinosinusitis, not considered as an outcome parameter in clinical trials on novel treatments for rhinitis and rhinosinusitis, and no target for routine treatment. In contrast to the simple nature of diagnosing NHR by a history of nasal symptoms induced by nonspecific exogenous and/or endogenous triggers, quantification is hardly performed in routine clinic given the lack of a simple tool for its diagnosis. So far, limited efforts have been invested into gaining better insight in the underlying pathophysiology of NHR, helping us to explain why some patients with inflammation develop NHR and others not. Of note, environmental and microbial factors have been reported to influence NHR, contributing to the complex nature of understanding the development of NHR. As a consequence of the neglect of NHR as a key clinical feature of rhinitis and chronic rhinosinusitis (CRS), patients with NHR might be suboptimally controlled and/or dissatisfied with current treatment. We here aim to provide a comprehensive overview of current knowledge on the pathophysiology, and the available tools to diagnose and treat NHR.

Nasal hyper-reactivity is a common feature in both allergic and nonallergic rhinitis.

BACKGROUND: Nasal hyper-reactivity is an increased sensitivity of the nasal mucosa to various nonspecific stimuli. Both allergic rhinitis (AR) and nonallergic rhinitis (NAR) patients can elicit nasal hyper-reactivity symptoms. Differences in the prevalence or type of nasal hyper-reactivity in AR and NAR patients are largely unknown. In this study, we quantitatively and qualitatively assessed nasal hyper-reactivity in AR and NAR. METHODS: In the first part, an analysis of a prospectively collected database was performed to reveal patient-reported symptoms of hyper-reactivity. In the second part, cold dry air provocation (CDA) was performed as a hyper-reactivity measure in AR and NAR patients and healthy controls, and symptoms scores, nasal secretions and peak nasal inspiratory flow were measured. Comparisons were made between AR and NAR patients in both studies. RESULTS: The database analysis revealed high hyper-reactivity prevalence in AR (63.4%) and NAR (66.9%). There were no differences between AR and NAR in terms of the number or type of hyper-reactivity stimuli. Hyper-reactivity to physical stimuli did not exclude a response to chemical stimuli, or vice versa. CDA provocation resulted in a significant increase in rhinitis symptoms and the amount of nasal secretions in AR and NAR patients, but not in controls. CONCLUSIONS: We found no quantitative or qualitative differences in nasal hyper-reactivity between AR and NAR patients. It is not possible to differentiate NAR subpopulations based on physical or chemical stimuli.

Application of a Cold Dry Air Provocation Test in Pediatric Patients with Asthma.

Asthma is a chronic inflammatory airway disease characterized by reversible airway obstruction and airway hyperreactivity. We proposed a cold dry air (CDA) provocation test and investigated its application in pediatric patients with asthma. We enrolled 72 children and adolescents older than 5 years who presented to our hospital with chronic cough, shortness of breath, and wheezing. We analyzed the results of allergy, pulmonary function, methacholine provocation, and CDA provocation tests. The FEV1 change 5 min after the provocation was recorded as CDA5 dFEV1; that after 15 min was recorded as CDA15 dFEV1. PT10 was the provocation time causing a 10% decrease in FEV1; a decrease of >10% in dFEV1 was considered a positive CDA test. Among the 72 subjects, 51 were diagnosed with asthma. A positive CDA test in patients with asthma correlated with non-eosinophilic asthma. In patients with asthma, sputum eosinophils and eosinophil cationic protein (ECP) levels of the patients with a positive CDA test were significantly lower than those of patients with a negative test. CDA5 dFEV1 correlated with PC20 and total immunoglobulin E. CDA15 dFEV1 correlated with PC20, sputum eosinophils, and ECP. PT10 became shorter as the peripheral blood eosinophil, FVC, FEV1, FEV1/FVC, and FEF25-75 decreased. The CDA provocation test showed airway hyperreactivity to non-specific stimuli, a high correlation with non-eosinophilic asthma, and the possibility of assessing asthma severity via PT10.

Diagnosis and treatment of non-allergic rhinitis: focus on immunologic mechanisms.

INTRODUCTION: Non-allergic rhinitis (NAR) is a heterogeneous nasal disease with high global prevalence. NAR can be subclassified as nonallergic rhinitis with eosinophilia syndrome (NARES), vasomotor rhinitis (VMR), and local allergic rhinitis (LAR). Although the precise factors involved in the etiology of NAR are not clear, there is evidence that immunological factors play an important role in the pathogenesis of NAR. This review provides a comprehensive overview of the immunological and neurogenic mechanisms involved in the diagnosis and treatment of NAR. AREAS COVERED: This review provides a comprehensive overview of the immunological basis of diagnostic and treatment strategies for NARES, VMR, and LAR. In particular, recently documented molecular and immunological mechanisms of NAR are discussed, which may help to better understand the mechanisms underlying the pathologies of the different endotypes of NAR. EXPERT OPINION: An increasing number of studies investigating the pathogenesis of NAR suggest that the immunological mechanisms underlying the different subtypes of NAR vary greatly, and are still not fully understood to accurately diagnose these subtypes. Thus, further studies should focus on making diagnosis and treatment of NAR more precise, safe, and effective. A better understanding of the immunological mechanisms involved in NAR should help in the discovery of new diagnostic and treatment strategies.

[Study on the diagnosis of idiopathic rhinitis by cold dry air provocation].

Objective:This study aimed to compare the nasal response of cold dry air（CDA） provocation in patients with idiopathic rhinitis（IR） and healthy individuals, and further assess its ability in diagnosing IR. Method:CDA provocation was performed among 15 healthy volunteers and 17 IR patients from Beijing Tongren Hospital Outpatient Department. Nasal symptom scores, total nasal volume（TNV）, total nasal resistance（TNR） and minimal cross-sectional area（MCA） were checked before and after the provocation. Logistic regression analysis and Receiver Operating Characteristic（ROC） curves were used in data evaluation. Result:Subjects in the IR group showed significantly larger changes after CDA provocation in total nasal symptom score（TNSS）, total nasal resistance（TNR）, minimal cross-sectional area（MCA） and total nasal volume（TNV）, compared with healthy volunteers. We built a predictive model for IR, Y=0.394×ΔTNSS-0.061 ×ΔTNV（%）+0.014×ΔTNV（%） -2.318, whose area under curve was 0.919 based on multi-factor logistic regression and ROC curve. According to the Youden index, the cut-off criteria was set to be Y >0.49, when its sensitivity and specificity were 82.4% and 84.6%, respectively. Conclusion:Aggravated nasal symptoms and decreased nasal ventilation could be seen after CDA provocation in the IR population. The CDA provocation provides a possible method for assisting the diagnosis of IR, and we'll expand the sample size in future research to verify its clinical application value.