Methodological Principles of Nasal Food Challenge.

Thanks to their valuable assessment possibilities (subjective complaints and changes in nasal patency during the examination), nasal provocation tests may serve as an alternative tool for oral food challenges in the future. However, this test requires successive attempts to regulate its methodology in order to develop a standardized lyophilisate form and determine the threshold dose for a positive result. The study objective was to present the methodological foundation for nasal food allergen provocation tests induced by freeze-dried powdered chicken egg whites. A control group of 25 individuals with no history of allergy to chicken eggs or any other allergy was included in the study. Optical rhinometry and visual analog scales were used to assess the response of nasal mucosa to local allergen challenges. Minor variations in nasal flows, as measured by optical rhinometry, were observed in the provocation tests. The mean optical density measurements (as measured regardless of the allergen dose used) varied from positive to negative values and vice versa, e.g., amounting to 0.018 OD (standard deviation 0.095) at 15 min and -0.011 OD (standard deviation 0.090) at 30 min. No significant differences were observed concerning the perceived nasal discomfort using the visual analog scale. Due to the absence of nasal mucosal reactivity, nasal challenge is an excellent methodological tool for implementing food allergen tests.

Nasal IL-13 production identifies patients with late-phase allergic responses.

BACKGROUND: There is limited knowledge on how local cytokine secretion patterns after nasal allergen challenge correlate with clinical symptoms especially with regard to the "late allergic response," which occurs in approximately 40% to 50% of patients with allergy. OBJECTIVE: We sought to characterize the immunologic and clinical nasal responses to birch pollen allergen challenge with a special focus on the late allergic response. METHODS: In this randomized, double-blind, placebo-controlled trial, birch pollen-allergic participants were challenged with birch pollen extract (n = 20) or placebo (n = 10) on 3 consecutive days. On days 1 and 3, nasal secretions were collected at selected time points over a 24-hour time course for the measurement of 33 inflammatory mediators. Clinical responses were determined through subjective symptom scores and objective nasal airflow measurements. RESULTS: Provoked participants had significantly greater clinical responses and showed significant increases in tryptase and the soluble IL-33 receptor serum stimulation 2 (sST2) in nasal secretions within minutes compared with the placebo group. Eight of 20 provoked participants displayed high IL-13 levels 2 to 8 hours after allergen provocation. This group also showed significant changes in clinical parameters, with a secondary drop in nasal airflow measured by peak nasal inspiratory flow and increased symptoms of nasal obstruction, which significantly differed from IL-13 nonresponders after 6 hours. CONCLUSIONS: IL-13 response status correlates with clinical responses and type 2 cytokine responses in the late phase after allergen provocation.

Local allergic rhinitis in children: Clinical characteristics and role of basophil activation test as a diagnostic tool.

BACKGROUND: Local allergic rhinitis (LAR) is a condition involving a localized nasal allergic response in absence of systemic atopy. Most studies on LAR have been performed in adults. We aimed to describe clinical characteristics of LAR pediatric patients, its clinical evolution over a 7-year follow-up period and to study the role of basophil activation test (BAT), for its diagnosis. METHODS: Forty-four children with non-allergic rhinitis (NAR) were included (24 males, 20 females, aged under 15 years). Nasal allergen provocation test (NAPT) and BAT were performed with Dermatophagoides pteronyssinus and Phleum pratense. RESULTS: Seven patients (16%) were diagnosed of LAR. Six reacted to D pteronyssinus and one to P pratense. All LAR and 86% of NAR patients presented perennial symptoms. Fifty-seven percent of NAR and LAR patients referred persistent symptoms. Around half of NAR and LAR patients reported mild-moderate clinical manifestations. Three LAR patients associated conjunctival symptoms, proportionally more than NAR patients (19%, 7 out of 37). NAR patients presented bronchial asthma (n = 10) more frequently than LAR children (n = 1). More than half of LAR and NAR patients presented family history of atopy. BAT was negative in all LAR patients. On follow-up, 3 LAR patients and 10 of the 25 NAR patients who agreed to be retested, presented systemic sensitization. Dust mites were the most frequent allergen involved. CONCLUSIONS: LAR should be ruled out in children with NAR. Almost half of children with LAR develop systemic sensitization over time. BAT shows low sensitivity for the diagnosis of LAR in children.

[Evaluation of subjective scale in allergen nasal provocation test].

Objective:To compare the clinical value of visual analogue scale （VAS）, Lebel scale and total nasal symptom scores （TNSS） in evaluating nasal allergen provocation test （NAPT）. Methods:A total of 151 patients suspected of allergic rhinitis admitted to the Department of Otolaryngology-Head and Neck Surgery of our hospital from April 2020 to September 2020 were included, of which 76 were positive for house dust mites and 75 were negative for allergens. Nasal airway resistance（NAR） was measured by active anterior nasal manometry. Nasal symptoms were evaluated by VAS, Lebel and TNSS. House dust mite allergen was used for NAPT by spray method. An increase≥40% in NAR was used as the gold standard for objective evaluation of NAPT. ROC curves of VAS, Lebel and TNSS were drawn to compare the evaluation effectiveness of different subjective evaluation methods, and the optimal critical point of each ROC curve was obtained. Results:With NAR increased by ≥40% as the gold standard, the area under ROC curve of VAS was 0.884, and the sensitivity and specificity were 97.75% and 80.65%, respectively. The area under ROC curve of Lebel was 0.773, and the sensitivity and specificity were 68.54% and 75.81%, respectively. The area under ROC curve of TNSS was 0.792, and the sensitivity and specificity were 68.54% and 79.03%, respectively. There was no significant difference between Lebel and TNSS（P>0.05）. The VAS differed significantly from Lebel and TNSS（P<0.05）. The Kappa values of VAS, Lebel, TNSS and NAR were 0.803, 0.432 and 0.459, respectively. Conclusion:The VAS, Lebel, TNSS subjective scale and NAR are consistent in evaluating the efficacy of NAPT, with the VAS assessment showing highest consistency with NAR. As objective assessment instruments are not widely used in China, subjective assessment method could be adopted to evaluate the efficacy of NAPT in clinical practice, and VAS scale is recommended as a priority.

[Value of allergen nasal provocation test in assessment of the efficacy of house dust mites specific immunotherapy].

Objective:To investigate the value of nasal provocation test（NPT） in evaluating the efficacy of allergen immunotherapy（AIT） in patients with dust mite induced allergic rhinitis（AR）. Methods:A total of 83 patients with dust mite induced AR with/without asthma were included. Symptom score（SS）, daily medication score（DMS）, combined symptom and medication score（CSMS）, rhinoconjunctivitis quality of life questionnaire（RQLQ）, NPT and skin prick test（SPT） were assessed before and after 1 year AIT. Results:There were statistical differences in SS（P<0.000 1）, DMS（P<0.000 1）, CSMS（P<0.000 1）, and RQLQ（P<0.000 1） after 1 year of AIT compared with pre-treatment. The effective rate of CSMS was 73.49%, and the effective rate of NPT was 42.17%. CSMS was consistent with NPT in efficacy assessment（Kappa=0.437, P<0.001）; while in 54 patients with pre-treatment NPT concentrations other than the original concentration, CMSM and NPT showed better consistence（Kappa=0.895, P<0.001）. Among the 48 patients with ineffective NPT assessment in the first year, 25 patients completed the second-year follow-up, and 12 patients（48.00%） showed effective in NPT. However, 10 out of 12 patients（83.33%） with NPT concentration other than original solution pre-treatment showed effective NPT at the second year. Conclusion:NPT can be used as one of the indicators for efficacy evaluation for dust mite induced AR patients, especially for patients with positive NPT induced at lower concentrations before treatment.

[Research progress and clinical application of allergen nasal provocation test].

The allergen nasal provocation testing（NPT）, in which allergens are applied directly to the nasal mucosa under standard and controlled conditions to provoke the main symptoms of allergic rhinitis（AR）, reproduces the response of the upper respiratory tract to natural exposure to allergens under controlled conditions and is the only test currently available to confirm nasal reactivity to allergens. It is invaluable in studying the mechanisms of AR and in assessing the response to novel anti-allergic treatments. The test may play an increasingly important role in clinical practice, especially in the identification of local AR, the diagnosis of occupational AR, the clarification of the composition of allergens, the assessment of the efficacy of AR treatment and the selection of candidates undergoing allergen immunotherapy. This article reviewed the application of NPT in the diagnosis of allergic and non-allergic rhinitis, and also introduces the indications, contraindications, advantages and limitations of NPT in evaluating nasal response.

Local allergic rhinitis in children.

Local allergic rhinitis (LAR) is one of the endotypes of rhinitis. Despite much data about epidemiology diagnosis and treatment in adult patients with LAR, there is little information on children. Many studies indicate the need for such an assessment of the phenomenon in children, which results in one meta-analysis based on young patients selected from cohorts of patients of different ages.

Nasal allergen challenge (NAC): Practical aspects and applications from an EU/US perspective-a Work Group Report of the AAAAI Rhinitis, Rhinosinusitis and Ocular Allergy Committee.

Nasal allergen challenge (NAC) is applied in a variety of settings (research centers, specialty clinics, and hospitals) as a useful diagnostic and research tool. NAC is indicated for diagnosis of seasonal and perennial allergic rhinitis, local allergic rhinitis, and occupational rhinitis; to design the composition of allergen immunotherapy in patients who are polysensitized; and to investigate the physio-pathological mechanisms of nasal diseases. NAC is currently a safe and reproducible technique, although it is time- and resource-consuming. NAC can be performed by a variety of methods, but the lack of a uniform technique for performing and recording the outcomes represents a challenge for those considering NAC as a clinical tool in the office. The availability of standardized allergens for NAC is also different in each country. The objective of this workgroup report is to review the current information about NAC, focusing on the practical aspects and application for diagnosis of difficult rhinitis phenotypes (eg, local allergic rhinitis, occupational rhinitis), taking into account the particular context of practice in the United States and the European Union.

Nasal Provocation Challenges with Aedes aegypti Whole-Body Extract Induces Allergic Rhinitis.

BACKGROUND: Exposure to mosquitoes in the Tropics is perennial, and their somatic and saliva antigens have shown IgE binding capacity, although it is not clear whether this is due to cross-reactivity or primary sensitization. Inhalation of these allergens could trigger an allergic response. OBJECTIVE: The aim of the study was to evaluate the clinical relevance of sensitization to Aedes aegypti in a group of patients with allergic rhinitis. METHODS: A cross-sectional study with allergic rhinitis subjects and healthy controls sensitized to mosquito extract was performed. Sensitization to mosquito and house dust mites was evaluated using skin prick test (SPT) and antibody determination by ELISA. Nasal provocation test (NPT) with whole-body extract was used to determine clinical relevance. RESULTS: Allergic rhinitis patients were more sensitized to mosquito extract than controls with (+) SPT (66.6% vs. 7.6%). From these (+) SPT patients, 44.5% had (+) NPT, and just two (11%) presented mono-sensitization to mosquito. Antibody reactivity was similar between patients and controls; however, (+) NPT patients showed a tendency to had higher levels of IgE and IgG4. DISCUSSION: Mosquitoes are perennial in most tropical areas, and their body allergens could be associated with respiratory allergies.

Local Allergic Rhinitis: Lights and Shadows of a Mysterious Entity.

Local allergic rhinitis (LAR) is, to date, a debated and complex entity, still orphan of global consideration and a multicentric approach. LAR does not seem to find a proper positioning in the classic classifications and phenotypes of chronic rhinitis, and its pathophysiology relies specifically on the presence of local IgE. These patients in fact have a suggestive clinical history of allergic rhinitis in the presence of negative skin prick tests and serum IgE tests for the suspect allergen. Nasal allergen challenge, assessment of local IgE, basophil activation test (BAT), and nasal cytology are, at the moment, the most used tests in the diagnostic approach to the disease, despite their limitations. Considering that the correct interpretation of diagnostic tests and their clinical relevance is fundamental in the assessment of the right diagnosis and the subsequent therapy, we propose a new diagnostic approach that encompasses all of these methodologies and suggest that several pragmatic randomized control trials as well as prospective, multicentric studies directed at the long-term follow-up of LAR be carried out to further investigate this debated entity.

Value of allergen nasal provocation test in assessment of the efficacy of house dust mites specific immunotherapy / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the value of nasal provocation test（NPT） in evaluating the efficacy of allergen immunotherapy（AIT） in patients with dust mite induced allergic rhinitis（AR）. Methods:A total of 83 patients with dust mite induced AR with/without asthma were included. Symptom score（SS）, daily medication score（DMS）, combined symptom and medication score（CSMS）, rhinoconjunctivitis quality of life questionnaire（RQLQ）, NPT and skin prick test（SPT） were assessed before and after 1 year AIT. Results:There were statistical differences in SS（P<0.000 1）, DMS（P<0.000 1）, CSMS（P<0.000 1）, and RQLQ（P<0.000 1） after 1 year of AIT compared with pre-treatment. The effective rate of CSMS was 73.49%, and the effective rate of NPT was 42.17%. CSMS was consistent with NPT in efficacy assessment（Kappa=0.437, P<0.001）; while in 54 patients with pre-treatment NPT concentrations other than the original concentration, CMSM and NPT showed better consistence（Kappa=0.895, P<0.001）. Among the 48 patients with ineffective NPT assessment in the first year, 25 patients completed the second-year follow-up, and 12 patients（48.00%） showed effective in NPT. However, 10 out of 12 patients（83.33%） with NPT concentration other than original solution pre-treatment showed effective NPT at the second year. Conclusion:NPT can be used as one of the indicators for efficacy evaluation for dust mite induced AR patients, especially for patients with positive NPT induced at lower concentrations before treatment.

Evaluation of subjective scale in allergen nasal provocation test / 临床耳鼻咽喉头颈外科杂志

Objective:To compare the clinical value of visual analogue scale （VAS）, Lebel scale and total nasal symptom scores （TNSS） in evaluating nasal allergen provocation test （NAPT）. Methods:A total of 151 patients suspected of allergic rhinitis admitted to the Department of Otolaryngology-Head and Neck Surgery of our hospital from April 2020 to September 2020 were included, of which 76 were positive for house dust mites and 75 were negative for allergens. Nasal airway resistance（NAR） was measured by active anterior nasal manometry. Nasal symptoms were evaluated by VAS, Lebel and TNSS. House dust mite allergen was used for NAPT by spray method. An increase≥40% in NAR was used as the gold standard for objective evaluation of NAPT. ROC curves of VAS, Lebel and TNSS were drawn to compare the evaluation effectiveness of different subjective evaluation methods, and the optimal critical point of each ROC curve was obtained. Results:With NAR increased by ≥40% as the gold standard, the area under ROC curve of VAS was 0.884, and the sensitivity and specificity were 97.75% and 80.65%, respectively. The area under ROC curve of Lebel was 0.773, and the sensitivity and specificity were 68.54% and 75.81%, respectively. The area under ROC curve of TNSS was 0.792, and the sensitivity and specificity were 68.54% and 79.03%, respectively. There was no significant difference between Lebel and TNSS（P>0.05）. The VAS differed significantly from Lebel and TNSS（P<0.05）. The Kappa values of VAS, Lebel, TNSS and NAR were 0.803, 0.432 and 0.459, respectively. Conclusion:The VAS, Lebel, TNSS subjective scale and NAR are consistent in evaluating the efficacy of NAPT, with the VAS assessment showing highest consistency with NAR. As objective assessment instruments are not widely used in China, subjective assessment method could be adopted to evaluate the efficacy of NAPT in clinical practice, and VAS scale is recommended as a priority.

Research progress and clinical application of allergen nasal provocation test / 临床耳鼻咽喉头颈外科杂志

The allergen nasal provocation testing（NPT）, in which allergens are applied directly to the nasal mucosa under standard and controlled conditions to provoke the main symptoms of allergic rhinitis（AR）, reproduces the response of the upper respiratory tract to natural exposure to allergens under controlled conditions and is the only test currently available to confirm nasal reactivity to allergens. It is invaluable in studying the mechanisms of AR and in assessing the response to novel anti-allergic treatments. The test may play an increasingly important role in clinical practice, especially in the identification of local AR, the diagnosis of occupational AR, the clarification of the composition of allergens, the assessment of the efficacy of AR treatment and the selection of candidates undergoing allergen immunotherapy. This article reviewed the application of NPT in the diagnosis of allergic and non-allergic rhinitis, and also introduces the indications, contraindications, advantages and limitations of NPT in evaluating nasal response.

Rinite alérgica persistente com elevada sensibilização a pólen de gramíneas: a medicina personalizada pode identificar os verdadeiros alérgicos a polens na imunoterapia / Persistent allergic rhinitis with high sensitization to grass pollen: personalized medicine can identify immunotherapy patients who are truly allergic to pollen

Este trabalho teve como objetivo avaliar pacientes com rinite alérgica persistente, sensibilizados a ácaros domésticos, associado à elevada sensibilização por pólen de gramíneas, sem sintomatologia estacional. Usou-se como método o diagnóstico molecular por componentes para selecionar os verdadeiramente alérgicos ao pólen de gramíneas. Foi realizado um estudo retrospectivo com análise de prontuários de pacientes em áreas de Caxias do Sul e municípios próximos no estado do RS, nos anos de 2016 e 2017, com as mesmas características climáticas. Foram selecionados 50 pacientes com alergia a ácaros, através de teste de punctura (pápula > 5 mm) associado ao pólen de gramíneas (pápula de > 7 mm) sem sintomatologia na primavera. Um total de 52% era do sexo feminino, a idade variou entre 4 e 56 anos, com uma média de 26,6 anos. Pesquisou-se a dosagem de IgE específica no soro para antígenos moleculares de pólen de gramíneas como estes: Phl p1, Phl p5, Cyn d1, em todos os pacientes. Houve 13 pacientes (26%) com diagnóstico, pelo menos, a um dos antígenos moleculares estudados. A amostra restringida apresentou 5 (10%) deles que possuíam Phl p5 > Phl p1, ou seja, eram verdadeiramente alérgicos à subfamília Poideae, enquanto 2 (4%) apresentaram Cyn d1 (subfamília Chloridoideae) > Phl p1. O estudo mostra que, em pacientes com rinite alérgica persistente, polissensibilizados a ácaros associados a pólen de gramíneas, sem sintomas estacionais característicos, os testes moleculares podem diagnosticar os verdadeiros alérgicos ao pólen.

This study aimed to evaluate patients with persistent allergic rhinitis who are sensitized to house mites and have high sensitization to grass pollen without seasonal symptoms. Molecular diagnosis was used to determine patients truly allergic to grass pollen. This retrospective study analyzed the medical records of patients from areas of Caxias do Sul and nearby municipalities (all with the same climatic characteristics) in the state of Rio Grande do Sul, Brazil between 2016 and 2017. Fifty patients allergic to dust mites were selected through a prick test (papule > 5 mm) and grass pollen (papule > 7 mm), but were asymptomatic in the spring. A total of 52% were female, and their ages ranged from 4 to 56 (mean 26.6) years. Specific serum IgE levels for grass pollen antigens, such as Phl p1, Phl p5, and Cyn d1, were investigated in all patients. Thirteen patients (26%) were diagnosed with at least one studied molecular antigen. The restricted sample included 5 (10%) patients with Phl p5 > Phl p1, ie, truly allergic to the Pooideae subfamily, while 2 (4%) had Cyn d1 (Chloridoideae subfamily) > Phl p1. The results indicate that among patients with persistent allergic rhinitis polysensitized to mites and grass pollen but without characteristic seasonal symptoms, molecular tests can diagnose those who are truly allergic to pollen.

Improvement of inattentive and hyperactive symptoms after real-life rhinitis treatment in school-aged children.

OBJECTIVES: Rhinitis treatment may improve attention-deficit/hyperactivity symptoms in children. The current study evaluated changes in inattentive and hyperactive symptoms after treatment in children with chronic rhinitis. METHODS: Children aged 5-18 years with chronic rhinitis were enrolled in a 3-month prospective study. The nasal provocation test for house dust mites (HDM) and evaluation of allergen sensitization, including the skin prick test and the Phadiatop test, were performed. The severity of rhinitis was assessed according to the ARIA guideline. The total nasal symptom score and the Vanderbilt ADHD Diagnostic Rating Scale (VADRS) score for assessing inattentive and hyperactive symptoms were recorded at baseline and at 1 and 3 months after rhinitis treatment. Children with rhinitis were classified into the following two groups: HDM-induced allergic rhinitis (AR group) and non-allergic rhinitis to HDM (NAR group) based on the NPT. RESULTS: Overall, 83 children completed the 3-month prospective study, and they had a mean age of 9.12 ± 2.89 years and 44.6% were boys. After rhinitis treatment, VADRS scores assessed by the parents and teachers were significantly decreased compared with those at baseline (p = 0.005). In subgroup analysis, 61 (73.49%) children had AR, and 22 (26.5%) children had NAR. No significant difference in the baseline VADRS score was found between the AR and NAR groups. After treatment, VADRS scores assessed by the parents and teachers were significantly decreased only in the AR group (p < 0.001). Forty-five (54.2%) children had moderate persistent rhinitis, 29 (34.9%) had mild persistent rhinitis, and 9 (10.8%) had mild intermittent symptoms. There were no differences in baseline VADRS scores assessed by the parents and teachers among children with mild intermittent, mild persistent, or moderate persistent symptoms. The total nasal symptom score and VADRS score were significantly decreased after treatment for all severities of rhinitis compared with those at baseline. A greater baseline VADRS score was associated with substantial improvement of inattentive and hyperactive symptoms after treatment. CONCLUSION: Early treatment for rhinitis may improve inattentive and hyperactive symptoms in school-aged children.

Sequential class switch recombination to IgE and allergen-induced accumulation of IgE+ plasmablasts occur in the nasal mucosa of local allergic rhinitis patients.

BACKGROUND: The involvement of allergen-specific (s)IgE in local allergic rhinitis (LAR) has been debated. Here, we investigate the effect of nasal allergen challenge with Dermatophagoides pteronyssinus (NAC-DP) in mucosal and peripheral B-cell subpopulations in LAR patients. METHODS: Nine LAR, 5 allergic rhinitis (AR), and 5 non-atopic healthy control (HC) individuals were subjected to a 3-day NAC-DP protocol, and nasal biopsies and blood samples were collected before and after provocation. Nasal biopsies were used for immunohistochemistry and gene expression studies, whereas the frequency of lymphocyte subsets and basophil activation test (BAT) were analyzed in blood samples by flow cytometry. sIgG was measured in sera. RESULTS: NAC-DP induced an increase in IgE+ CD38+ plasmablasts in the nasal mucosa of LAR patients, but not in AR or HC individuals. Markers of sequential recombination to IgE (εCSR) (from IgG) were observed in 33% of LAR, 20% of AR, and 0% of HC subjects. NAC-DP increased the proportion of peripheral CD19+ CD20+ CD38+ plasmablasts in AR and LAR patients, but not in HC. Expression of the mucosal homing receptor CXCR3 in peripheral CD19+ CD20+ CD38+ plasmablasts from LAR, AR, and HC individuals was 7%, 5%, and 0.5%, respectively. In vitro DP stimulation increased proliferating CD19+ CD20+ CD38+ plasmablasts in LAR and AR patients, but not in HC. Serum DP-sIgG was higher in LAR and AR patients as compared to HC. BAT was positive in 33%, 100%, and 0% of LAR, AR, and HC subjects, respectively. CONCLUSION: These results suggest that allergen exposure induces the sequential εCSR of IgG+ CD19+ CD20+ CD38+ plasmablasts in the nasal mucosa of LAR patients.

Local allergic rhinitis in children: A systematic review.

BACKGROUND: Local allergic rhinitis (LAR) is a well-defined and reported phenotype in adults, but data is scarce for children and adolescents, and it is probably an undiagnosed and highly underestimated condition in childhood. OBJECTIVES: The objectives of this systematic review were to identify original observational studies published on LAR in children and adolescents and to describe the prevalence and characteristics of this phenotype in the pediatric age group. METHODS: A systematic search was performed in PubMed and EMBASE databases. The search was limited to publications on humans, written in English, published between January 1, 2000 and September 20, 2021. Participants had to be under 18 years old and with a diagnosis of LAR confirmed by nasal allergen provocation test (NAPT). RESULTS: Ten articles were identified. Despite the wide variability of protocols, prevalence rates ranged from 3.7 to 83.3% among children previously diagnosed as having nonallergic rhinitis, being markedly lower in Eastern countries (3.7-16.6%) when compared to Western countries (22.3-83.3%). To date, no relevant clinical characteristics capable of differentiating LAR patients from other childhood rhinitis phenotypes have been identified. CONCLUSIONS: LAR is an allergic rhinitis phenotype also found in children. Population and regional differences and differences in NAPT protocols may explain the heterogeneity in LAR prevalence rates observed in different parts of the world. In addition to clarifying this large discrepancy, longitudinal studies are also needed to assess the clinical characteristics of the LAR phenotype in the pediatric age group, and its stability into adulthood must be confirmed.

Local allergic rhinitis in children: A systematic review

Background Local allergic rhinitis (LAR) is a well-defined and reported phenotype in adults, but data is scarce for children and adolescents, and it is probably an undiagnosed and highly underestimated condition in childhood.Objectives The objectives of this systematic review were to identify original observational studies published on LAR in children and adolescents and to describe the prevalence and characteristics of this phenotype in the pediatric age group.Methods A systematic search was performed in PubMed and EMBASE databases. The search was limited to publications on humans, written in English, published between January 1, 2000 and September 20, 2021. Participants had to be under 18 years old and with a diagnosis of LAR confirmed by nasal allergen provocation test (NAPT).Results Ten articles were identified. Despite the wide variability of protocols, prevalence rates ranged from 3.7 to 83.3% among children previously diagnosed as having nonallergic rhinitis, being markedly lower in Eastern countries (3.7–16.6%) when compared to Western countries (22.3–83.3%). To date, no relevant clinical characteristics capable of differentiating LAR patients from other childhood rhinitis phenotypes have been identified.Conclusions LAR is an allergic rhinitis phenotype also found in children. Population and regional differences and differences in NAPT protocols may explain the heterogeneity in LAR prevalence rates observed in different parts of the world. In addition to clarifying this large discrepancy, longitudinal studies are also needed to assess the clinical characteristics of the LAR phenotype in the pediatric age group, and its stability into adulthood must be confirmed (AU)

Airway Nitric Oxide in Children with HDM-Induced Allergic Rhinitis.

BACKGROUND: Rhinitis is a common problem in children. Airway nitric oxide (NO) was proposed to represent eosinophilic inflammation. OBJECTIVES: To evaluate airway NO level in children with house dust mite (HDM)-induced allergic rhinitis. METHODS: Children aged 5 to 18 years old with moderate-severe persistent rhinitis and positive result for the HDM nasal provocation test (NPT) was enrolled. The nasal symptoms evaluated by total nasal symptom score (TNSS) and visual analog scale (VAS) were recorded. Skin prick test (SPT) to common aeroallergens, fractional exhaled nitric oxide (FeNO), nasal nitric oxide (nNO), and blood test for specific IgE (sIgE) to HDM was measured. Rhinitis severity was categorized as severe if the VAS score > 7. RESULTS: Forty-eight children with HDM-induced allergic rhinitis with the mean age of 9.3 ± 2.4 years were enrolled. nNO levels and VAS score were significantly correlated (R = 0.398, P = .005). Children with severe rhinitis had significantly higher nNO levels than moderate rhinitis (1652.05 vs 941.30 parts per billion [ppb], P = .002), while there was no difference in FeNO level. ROC curve analysis demonstrated the cut-off value of nNO at 1350 ppb (AUC 0.764, 95% CI: 0.616-0.911, P = .002) for detecting severe HDM-induced allergic rhinitis with the sensitivity of 78% and the specificity of 71%. The level of FeNO in children who had HDM mean wheal diameter (MWD) > 8 mm was significantly higher than those with HDM MWD of 3 to 8 mm and those with a negative test (39.7 vs 14.3 vs 14.4 ppb; P = .006, respectively). Children who had sIgE to HDM < 0.35 KUA/L had significantly lower FeNO than those with sIgE to HDM 0.35 to 50 KUA/L and >50 KUA/L (9.5 vs 19.7 vs 40.4 ppb; P = .029, respectively). CONCLUSIONS: Cut-off value for the diagnosis of severe HDM-induced chronic rhinitis was proposed. Rhinitis children who had a higher degree of HDM sensitization had a higher level of FeNO.

The Importance of Nasal Provocation Testing in the Diagnosis of Dermatophagoides pteronyssinus-Induced Allergic Rhinitis.

BACKGROUND: Allergen identification is the first step for allergen-specific immunotherapy (AIT) of allergic rhinitis (AR). Currently, the diagnosis of AR is based mainly on the positive results of the skin prick test (SPT) and/or serum specific immunoglobulin E (sIgE) measurement. However, the results of these two tests may not always directly correlate with AR. OBJECTIVE: To investigate the importance of nasal provocation testing (NPT) in the diagnosis of Dermatophagoides pteronyssinus (Der p)-induced AR. METHODS: Rhinitis patients willing to undergo AIT (n = 171) were enrolled. The correlations of Der p SPT, sIgE, NPT, and clinical symptom severity were assessed. RESULTS: NPT-positive responses were more common in patients with higher SPT and sIgE levels. The optimal cut-off value for a NPT-positive response for SPT was 5.5 mm and for sIgE was 2.77 kUA/L, based on the respective receiver operating characteristic (ROC) curves. The area under the curve (AUC) of the ROCs was 0.814 (SPT only) and 0.794 (sIgE only) and increased to 0.828 with the combination of SPT and sIgE. The Der p-NPT concentration was inversely correlated with SPT and sIgE levels (r = -0.477, P < .001, and r = -0.461, P < .001, respectively), but none was correlated with the total nasal symptom score. CONCLUSION: For patients who are willing to receive Der p AIT, NPT is a useful and safe test to confirm diagnosis prior to treatment initiation, especially in patients with lower levels of Der p SPT (< 5.5 mm) or sIgE (< 2.77 kUA/L).