[Component-resolved diagnosis of tree pollen allergen: identify key allergens to develop treatment plans].

With the increasing global prevalence of tree pollen allergies, there has been a significant impact on the quality of life for populations. In North and Central China, birch pollen, cypress pollen, and plane tree pollen are the most common allergens for springtime pollen allergy sufferers. The distribution of plants and patterns of pollen transmission in different geographical areas result in varying pollen exposure outcomes, further complicating the challenges in diagnosis and individualized treatment. This article delves into the research progress and clinical application of tree pollen allergies based on the "Molecular Allergology User's Guide 2.0 (MAUG 2.0) " published by the European Academy of Allergy and Clinical Immunology (EAACI). It discusses major allergen families and component proteins of tree pollen such as PR-10 proteins, profilins, polcalcins, as well as cross-reactive components that may cause pollen-food allergy syndrome. Allergen component diagnostics can distinguish true allergy sufferers from those with multiple allergen reactions, enabling more targeted selection of allergens for specific immunotherapy, thus enhancing treatment effectiveness. Bet v 1 and Cup a 1, for instance, are specific indicators for immunotherapy in birch and cypress allergy patients. Overall, this article provides cutting-edge information for professionals in the field of tree pollen allergies, offering in-depth exploration of tree pollen allergen component proteins, clinical manifestations, and treatment-related research, aiding in better understanding and addressing the challenges of tree pollen allergies.

Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study.

BACKGROUND: Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach. OBJECTIVE: To describe sensitization profiles and clinical phenotypes of pollen allergic patients in nine Southern European cities with a uniform methodological approach. METHODS: Within the @IT.2020 multicenter observational study, pediatric and adult patients suffering from SAR were recruited in nine urban study centers located in seven countries. Clinical questionnaires, skin prick tests (SPT) and specific IgE (sIgE) tests with a customized multiplex assay (Euroimmun Labordiagnostika, Lübeck, Germany) were performed. RESULTS: Three hundred forty-eight children (mean age 13.1 years, SD: 2.4 years) and 467 adults (mean age 35.7 years SD: 10.0 years) with a predominantly moderate to severe, persistent phenotype of SAR were recruited. Grass pollen major allergenic molecules (Phl p 1 and/or Phl p 5) ranged among the top three sensitizers in all study centers. Sensitization profiles were very heterogeneous, considering that patients in Rome were highly poly-sensitized (sIgE to 3.8 major allergenic molecules per patient), while mono-sensitization was prominent and heterogeneous in other cities, such as Marseille (sIgE to Cup a 1: n = 55/80, 68.8%) and Messina (sIgE to Par j 2: n = 47/82, 57.3%). Co-sensitization to perennial allergens, as well as allergic comorbidities also broadly varied between study centers. CONCLUSIONS: In Southern European countries, pollen allergy is heterogeneous in terms of sensitization profiles and clinical manifestations. Despite the complexity, a unique molecular, multiplex, and customized in-vitro IgE test detected relevant sensitization in all study centers. Nevertheless, this geographical diversity in pollen allergic patients imposes localized clinical guidelines and study protocols for clinical trials of SAR in this climatically complex region.

Identification of Pla a 7 as a novel pollen allergen group in Platanus acerifolia pollen.

BACKGROUND: Platanus acerifolia is recognized as a source of allergenic pollen worldwide. Currently, five Platanus acerifolia pollen allergens belonging to different protein families have been identified, in which profilin and enolase were characterized by our group recently. Besides, we also screened and identified a novel allergen candidate as triosephosphate isomerase, which was different from already known types of pollen allergens. However, the role of this novel allergen group in Platanus acerifolia pollen allergy was unclear. Therefore, we further investigated the allergenicity and clarify its clinical relevance in this study. METHODS: The natural triosephosphate isomerase from Platanus acerifolia pollen was purified by three steps of chromatography and identified by mass spectrometry. The cDNA sequence of this protein was matched from in-house transcripts based on internal peptide sequences, which was further confirmed by PCR cloning. The recombinant triosephosphate isomerase was expressed and purified from E. coli. Allergenicity analysis of this protein was carried out by enzyme linked immunosorbent assay, immunoblot, and basophil activation test. RESULTS: A novel allergen group belonging to triosephosphate isomerase was firstly identified in Platanus acerifolia pollen and named as Pla a 7. The cDNA of Pla a 7 contained an open reading frame of 762 bp encoding 253 amino acids. The natural Pla a 7 displayed 41.4% IgE reactivity with the patients' sera by ELISA, in which the absorbance value showed correlation to the serum sIgE against Platanus acerifolia pollen extract. Inhibition of IgE-binding to pollen extracts reached 26%-94% in different Pla a 7-positive sera. The recombinant Pla a 7 exhibited weaker IgE-reactivity in ELISA than its natural form, but showed comparable activity in immunoblot. The allergenicity was further confirmed by basophil activation test. CONCLUSIONS: Triosephosphate isomerase (Pla a 7) was first recognized as pollen allergen in Platanus acerifolia pollen, which is a completely different type of pollen allergen from those previously reported. This finding is essential to enrich information on allergen components and pave the way for molecular diagnosis or treatment strategies for Platanus acerifolia pollen allergy.

Evaluation of the reproducibility of responses to nasal allergen challenge and effects of inhaled nasal corticosteroids.

BACKGROUND: Similar immune responses in the nasal and bronchial mucosa implies that nasal allergen challenge (NAC) is a suitable early phase experimental model for drug development targeting allergic rhinitis (AR) and asthma. We assessed NAC reproducibility and the effects of intranasal corticosteroids (INCS) on symptoms, physiology, and inflammatory mediators. METHODS: 20 participants with mild atopic asthma and AR underwent three single blinded nasal challenges each separated by three weeks (NCT03431961). Cohort A (n = 10) underwent a control saline challenge, followed by two allergen challenges. Cohort B (n = 10) underwent a NAC with no treatment intervention, followed by NAC with 14 days pre-treatment with saline nasal spray (placebo), then NAC with 14 days pre-treatment with INCS (220 µg triamcinolone acetonide twice daily). Nasosorption, nasal lavage, blood samples, forced expiratory volume 1 (FEV1), total nasal symptom score (TNSS), peak nasal inspiratory flow (PNIF) were collected up to 24 h after NAC. Total and active tryptase were measured as early-phase allergy biomarkers (≤30 min) and IL-13 and eosinophil cell counts as late-phase allergy biomarkers (3-7 h) in serum and nasal samples. Period-period reproducibility was assessed by intraclass correlation coefficients (ICC), and sample size estimates were performed using effect sizes measured after INCS. RESULTS: NAC significantly induced acute increases in nasosorption tryptase and TNSS and reduced PNIF, and induced late increases in nasosorption IL-13 with sustained reductions in PNIF. Reproducibility across NACs varied for symptoms and biomarkers, with total tryptase 5 min post NAC having the highest reproducibility (ICC = 0.91). Treatment with INCS inhibited NAC-induced IL-13 while blunting changes in TNSS and PNIF. For a similar crossover study, 7 participants per treatment arm are needed to detect treatment effects comparable to INCS for TNSS. CONCLUSION: NAC-induced biomarkers and symptoms are reproducible and responsive to INCS. NAC is suitable for assessing pharmacodynamic activity and proof of mechanism for drugs targeting allergic inflammation.

Allergic Rhinitis.

Allergic rhinitis (AR) affects more than 400 million people worldwide, making it 1 of the most prevalent chronic diseases. Childhood AR is increasing, and almost half of patients with AR develop symptoms before age 6 years. Although a diagnosis of AR is associated with higher socioeconomic status, underserved and urban populations have more indoor aeroallergen sensitizations and are likely underdiagnosed with AR, further exacerbating health-care disparities. AR negatively impacts quality of life, school performance, and overall health outcomes. Untreated AR in children increases the risk for poor asthma control, increased asthma severity, and exacerbations. Many patients believe that they have seasonal allergies only but in reality have both perennial and seasonal AR, which may change the approach to allergen avoidance measures and treatment recommendations. Pharmacotherapy of AR has expanded, with many intranasal corticosteroids, intranasal antihistamines, and second-generation oral antihistamines approved for pediatric use. Allergen immunotherapy, including both subcutaneous and sublingual forms, are approved for children and are disease modifying, potentially reducing further allergen sensitization and progression to asthma. Many of the currently available biological therapies indicated for pediatric asthma and/or atopic diseases reduce AR symptoms as well. Children with moderate to severe or refractory AR or those with comorbidities should be referred to allergists for diagnostic testing and expanded management options, including immunotherapy and potential biological treatment.

A Pilot Study to Identify Grass Species That Mediate Pollen Allergy in Thailand.

INTRODUCTION: Some grass species that are either common or widely spread in Thailand have not been used for pollen allergy diagnosis. In order to improve diagnostic accuracy, the aim of this pilot study was to identify the grass species responsible for pollen allergy in Thailand. METHODS: The skin sensitization of pollen extracts from six different grass species, including rice (Oryza sativa), corn (Zea mays), sorghum (Sorghum bicolor), para grass (Urochloa mutica), ruzi grass (Urochloa eminii), and green panic grass (Megathyrsus maximus), was evaluated by skin prick test (SPT). Serum's IgE specific to each pollen extract was analyzed by Western blot (WB). The ImmunoCAPTM test for Johnson grass was also evaluated. RESULTS: Of the thirty-six volunteers who participated in this study, eighteen tested positive for at least one of the diagnostic tests, namely SPT, WB analysis, or ImmunoCAPTM. Notably, skin reactivity to para grass, corn, sorghum, and rice was more commonly observed compared to ruzi grass and green panic grass. However, in the WB analysis, individuals with pollen-specific IgE were more frequently detected in sorghum, green panic grass, corn, rice, and ruzi grass than para grass. CONCLUSION: In this pilot investigation, our findings indicate that the pollen extracts of rice, corn, sorghum, and para grass are associated with pollen allergy in Thailand. These results contribute to the current knowledge on the identification of grass species that are associated with pollen allergy in Thailand and Southeast Asia.

The "allergic nose as a pollen detector" concept: e-Diaries to predict pollen trends.

Hirst pollen traps and operator pollen recognition are worldwide used by aerobiologists, providing essential services for the diagnosis and monitoring of allergic patients. More recently, semiautomated or fully automated detector systems have been developed, which facilitate prediction of pollen exposure and risk for the individual patient. In parallel, smartphone apps consisting of short questionnaires filled in daily by the patient/user provide daily scores, time trajectories, and descriptive reports of the severity of respiratory allergies in patients with pollen allergy. The usual scientific and clinical approach to this matter is to monitor the environment (pollen concentration) in order to predict the risk of symptoms (allergic rhinitis) in a population. We discuss here the opposite, contraintuitive possibility, that is, the use of e-diaries to collect daily information of mono-sensitized pollen-allergic patients in order to predict the clinically efficient airborne exposure to a given pollen, area, and time period. In line with the "Patient as Sensor" concept, proposed in 2013 by Bernd Resch, the "allergic nose" may be used as a pollen detector in addition to existing calibrated hardware sensors, namely the pollen stations, thus contributing with individual measurements, sensations, and symptoms' perception. The target of this review is to present a novel concept of pollen monitoring based on "pollen-detector" patients to inspire future cooperative studies aimed at investigating and hopefully validating our hypothesis.

Intranasal corticosteroid and antihistamine combinations in the treatment of allergic rhinitis: the role of the novel formulation olopatadine/mometasone furoate.

INTRODUCTION: Allergic rhinitis (AR) is a common disease with an important impact on the quality of life and very high management costs. In many patients, the poor control of rhinitis symptoms often requires the use of different drugs, and polytherapy tends to reduce therapeutic adherence. According to the latest version of ARIA guidelines, the currently recommended drugs for the treatment of moderate-to-severe AR are second-generation antihistamines, intranasal corticosteroids, and their combination, even in a single nasal spray device. A single medication with a rapid onset of action, acting on breakthrough symptoms too, would be advantageous, also in terms of patient compliance. AREAS COVERED: GSP301 (olopatadine 600 µg - mometasone furoate 25 µg) is a novel intranasal formulation, combining the second-generation antihistamine olopatadine hydrochloride with mometasone furoate. Here, we review the evidence for GSP301, especially concerning the efficacy and safety profile of this intranasal combination in the treatment of AR. EXPERT OPINION: The evidence provided in the current review clearly supports the use of GSP301 as a novel intranasal corticosteroid/antihistamine combination with a well-documented efficacy and safety profile in terms of rapid symptom relief and good tolerability.

Intralymphatic immunotherapy with birch and grass pollen extracts. A randomized double-blind placebo-controlled clinical trial.

INTRODUCTION: There is a need to evaluate the safety and efficacy of intralymphatic immunotherapy (ILIT) for inducing tolerance in patients with allergic rhinitis. METHODS: Thirty-seven patients with seasonal allergic symptoms to birch and grass pollen and skin prick test >3 mm and/or IgE to birch and timothy >0.35 kU/L were randomized to either ILIT, with three doses of 0.1 mL of birch pollen and 5-grass pollen allergen extracts on aluminium hydroxide (10,000 SQ-U/ml; ALK-Abelló) or placebo using ultrasound-guided intralymphatic injections at monthly intervals. Daily combined symptom medical score and rhinoconjunctivitis total symptom score were recorded during the peak pollen seasons the year before and after treatment. Rhinoconjunctivitis total symptom score, medication score and rhinoconjunctivitis quality of life questionnaire were recorded annually starting 2 years after treatment. Circulating proportions of T helper cell subsets and allergen-induced cytokine and chemokine production were analysed using flow cytometry and ELISA. RESULTS: There were no differences between the groups related to daily combined symptom medical score the year before and after treatment. Two years after ILIT (after unblinding), the actively treated group reported significantly fewer symptoms, lower medication use and improved quality of life than did the placebo group. After the pollen seasons the year after ILIT, T regulatory cell frequencies and grass-induced IFN-γ levels increased only in the actively treated group. CONCLUSION: In this randomized controlled trial, ILIT with birch and grass pollen extract was safe and accompanied by immunological changes. Further studies are required to confirm or refute the efficacy of the treatment.

[Research progress of oral allergy syndrome].

Oral allergy syndrome (OAS) is an IgE-mediated hypersensitivity. Patients with pollen allergy will experience oropharyngeal allergy after eating fresh fruits or vegetables containing homologous pathogenesis-related allergen, occasionally accompanied by systemic symptoms, it is a special type of food hypersensitivity in which respiratory allergens and food allergens are similar structurally and lead to the cross-reactivity. At present, there is little research and attention to it in China. To master the definition, epidemiological characteristics, pathological mechanism, diagnosis, prevention and treatment of OAS is very important to the prevention and control of OAS. This article reviews the research progress of OAS, providing reference and prevention basis for clinicians to improve the diagnosis and differential diagnosis of OAS.

Skin Physiology, Mucosal Functions, and Symptoms Are Modulated by Grass Pollen and Ozone Double Exposure in Allergic Patients.

INTRODUCTION: Along with climate changes, we see an increase in allergic symptoms and the number of pollen-allergic patients in many countries. Increased allergic symptoms are associated with an elevated ozone exposure which may be linked by impaired epithelial barrier function. This study aimed to quantify the clinical effect of ozone and pollen double exposure (DE). We tested whether ozone impairs barrier-related skin physiology and mucosal functions under DE with pollen in grass pollen-allergic patients versus healthy controls. METHODS: This case-control study included 8 grass pollen-allergic patients and 8 non-allergic healthy subjects exposed to grass pollen and ozone in the GA2LEN pollen chamber, comparing shorter and longer DE duration. Non-invasive skin physiological parameters were assessed, including stratum corneum hydration, skin redness, surface pH, and basal transepidermal water loss as a parameter for epidermal barrier function. The subjects' general well-being, bronchial, nasal, and ocular symptoms were documented. RESULTS: Skin physiology tests revealed that DE in allergic patients deteriorates the epidermal barrier function and increases the surface pH and skin redness. DE significantly induced nasal secretion in pollen-allergic versus healthy subjects, which was more pronounced with longer DE. The general well-being was significantly impaired under DE versus pollen or ozone alone, with a negative influence of DE duration. No relevant bronchial symptoms were recorded. CONCLUSION: Skin physiology and nasal mucosal symptoms are negatively affected by ozone and grass pollen DE in allergic patients. The negative effects showed, in some parameters, a dose (time)-response relationship. The pH can be regarded as a possible modulatory mechanism.

A comparison of experience sampled hay fever symptom severity across rural and urban areas of the UK.

Hay fever affects people differently and can change over a lifetime, but data is lacking on how environmental factors may influence this. This study is the first to combine atmospheric sensor data with real-time, geo-positioned hay fever symptom reports to examine the relationship between symptom severity and air quality, weather and land use. We study 36145 symptom reports submitted over 5 years by over 700 UK residents using a mobile application. Scores were recorded for nose, eyes and breathing. Symptom reports are labelled as urban or rural using land-use data from the UK's Office for National Statistics. Reports are compared with AURN network pollution measurements and pollen and meteorological data taken from the UK Met Office. Our analysis suggests urban areas record significantly higher symptom severity for all years except 2017. Rural areas do not record significantly higher symptom severity in any year. Additionally, symptom severity correlates with more air quality markers in urban areas than rural areas, indicating that differences in allergy symptoms may be due to variations in the levels of pollutants, pollen counts and seasonality across land-use types. The results suggest that a relationship exists between urban surroundings and hay fever symptoms.

Individual multidisciplinary clinical phenotypes of nasal and ocular symptoms in hay fever: Crowdsourced cross-sectional study using AllerSearch.

BACKGROUND: Multidisciplinary efforts to prospectively collect and analyze symptoms of hay fever are limited. We aimed to identify the characteristics of nasal and ocular symptoms of hay fever, using the AllerSearch smartphone application. METHODS: This mobile health-based prospective observational study using the AllerSearch smartphone application was conducted between February 1, 2018, and May 1, 2020. Individuals who downloaded AllerSearch from Japan and provided comprehensive self-assessments (including 17 items related to quality of life [QoL]-related items) were included. The characteristics and risk factors for allergic rhinitis (AR) and allergic conjunctivitis (AC) were identified using hierarchical heat maps and multivariate logistic regression. RESULTS: Of the 9041 participants with hay fever, 58.8% had AR and AC, 22.2% had AR, and 5.7% had AC. The AR-AC comorbid cohort showed worse symptoms of hay fever and QoL scores than the other cohorts. Factors (odds ratio, 95% confidence interval) associated with AR-AC included a lower age (0.98, 0.97-0.98), female sex (1.31, 1.19-1.45), liver disease (1.58, 1.26-2.35), dry eye disease (1.45, 1.30-1.63), unknown dry eye disease status (1.46, 1.31-1.62), contact lens use discontinuation during the hay fever season (1.69, 1.28-2.23), and bedroom flooring material other than hardwood, carpet, tatami, or vinyl (1.91, 1.16-3.14). CONCLUSIONS: Analysis of medical big data for hay fever performed using a mobile health app helped identify risk factors and characteristics of AC, AR, and AR-AC. Phenotyping of highly variable symptoms of hay fever, such as nasal and ocular symptoms, can facilitate better-quality clinical care.

Molecular Aspects of Allergen-Specific Immunotherapy in Patients with Seasonal Allergic Rhinitis.

A systematic review and narrative synthesis of publications was undertaken to analyze the role of component-resolved diagnosis technology in identifying polysensitization for the provision of allergen-specific immunotherapy to patients with seasonal allergic rhinitis. A search of publications was carried out in electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search helped to identify 568 publications, 12 of which were included in this review. Overall, 3302 patients were enrolled. The major finding was that component-resolved diagnostics change the choice of relevant allergens for allergen-specific immunotherapy in at least 50% of cases. Sensitization to allergen components differs with age, type of disease, and overall disease duration. Patients who had both bronchial asthma and allergic rhinitis were sensitized to a larger number of allergens than patients who had bronchial asthma alone.

Prevalence and clinical features of pollen-food allergy syndrome in adults with seasonal allergic rhinitis.

OBJECTIVE: Pollen-food allergy syndrome (PFAS) is an IgE-mediated allergic reaction to certain foods due to prior sensitization to pollen allergens. The data about the prevalence of PFAS in adults in Turkey is not sufficiently reported. Our objective was to investigate the frequency and clinical features of PFAS in adult patients with seasonal allergic rhinitis (SAR). PATIENTS AND METHODS: A total of 222 patients with SAR were enrolled in our outpatient allergy clinic at Hacettepe University, during a ten-month period. A questionnaire was used to evaluate patients and to categorize those who experienced obvious allergy symptoms consistent with PFAS. Atopy was assessed by a standard skin prick test panel including common aeroallergen extracts. RESULTS: Among 222 patients with a diagnosis of SAR, 31 had patient reported PFAS (31/222, 14%). Among them, 23 (74.2%) were females, and their mean age was 32.29±9.24 years. The most common symptoms were isolated oropharyngeal symptoms (58.1%), followed by urticaria (51.6%) after culprit food ingestion. The most frequent culprit foods were eggplant, walnut, kiwi, peach, and melon. The predominant sensitizing aeroallergen was grass pollen. CONCLUSIONS: PFAS can be frequently observed in adults who are followed up for SAR. The most frequently involved foods are eggplant, walnut, kiwi, peach, and melon in Ankara Province. The symptoms of PFAS are usually localized in the oropharyngeal area and are self-limited.

Extract-Shaped Immune Repertoires as Source for Nanobody-Based Human IgE in Grass Pollen Allergy.

The presence of allergen-specific IgE in serum is a biomarker for allergic disease. Specific IgE antibodies for research and diagnostics, however, remain scarce. In contrast to prototypic antibodies, camelid species have evolved single domains as moiety for antigen recognition. These so-called nanobodies represent a versatile platform for the development of diagnostic and therapeutic approaches. In this study, we aimed for generating nanobodies and derived IgE formats from an extract-shaped immune repertoire. Timothy grass pollen represents a complex, but well-defined mixture of individual allergens. Therefore, a repertoire library from a timothy grass pollen extract immunised llama was established. The selection by phage display yielded 3 nanobodies with immunoreactivity to the extract. IgE-like nanobody-based human IgE (nb-hIgE) antibodies were produced in mammalian cells and assessed in different immunoassays and commercial platforms. Immunoblotting and diagnostic ImmunoCap analysis of single timothy grass pollen allergens identified the major allergens Phl p 6 and Phl p 4 as targets. Assessment of immunoreactivity further documented significant molecular cross-reactivity with pollen extract of different grass species and variant presence of allergens within extracts of Pooideae grasses. In summary, our study shows that extract-based immunisation enables the generation of allergen-specific nanobodies and derived nb-hIgE formats linking nanobody technologies with allergological applications.

Pre-seasonal immunotherapy is effective in both monosensitized and polysensitized patients with allergic rhinitis.

Summary: Background. The effectiveness of pre-seasonal allergoid immunotherapy in polysensitized patients are not well-known. The aim of the present study was to compare the clinical efficacy and immunological changes of pre-seasonal allergoid immunotherapy in mono and polysensitized patients with grass pollen allergy. Methods. Fourty six patients with seasonal allergic rhinitis undergoing pre-seasonal grass pollen immunotherapy and 28 cases followed by conventional drug treatment were included. These groups were divided into monosensitized and polysensitized ones. All patients were followed between March-September with symptom-medication scores, and visual analogue scale (VAS). The quality of life was assessed using the Mini-RQLQ questionnaire. Phleum pratense (Phl p) specific IgE and IgG4 (UNI-CAP 100, Phadia) measurements were performed before and after 7 weeks of immunotherapy. Results. In the immunotherapy group, 15th weekly symptom-medication scores and VAS scores between May and August were found to be significantly lower than those in the control group (p < 0.05). Phl p specific IgE and IgG4 levels were significantly higher after immunotherapy compared to those before immunotherapy (p = 0.001). Furthermore, Phl p specific IgG4 levels after immunotherapy were also significantly higher than in the control group (p = 0.001). Improvements in activities-practical problems and non-nose/eye symptoms quality of life scores were significantly different between two groups (p < 0.05). There was no difference in terms of clinical and immunological parameters in mono- and polysensitized patients (p > 0.05). Conclusions. This study indicates that clinical improvement with pre-seasonal grass pollen immunotherapy is accompanied by important increase in specific IgG4 blocking antibodies. Furthermore, a single-allergen immunotherapy can lead to similar clinical efficacy and immunological changes in polysensitized as well as monosensitized patients with grass pollen allergy.

Regional differences in the prevalence of oral allergy syndrome among Japanese children: A questionnaire-based survey.

BACKGROUND: Oral allergy syndrome (OAS) is characterized by an immediate allergic reaction that mainly or partially affects the oral mucosa, pharynx, or lips, and it is usually caused by ingesting fresh fruits or vegetables. Most patients with OAS also have allergic rhinitis due to pollen. As allergic rhinitis is increasingly prevalent in the Japanese population and the age at disease development is decreasing, morbidity associated with OAS among the younger population is likely to increase. However, there is little information about the prevalence of this disease among Japanese children, specifically the influences of residency in regions with different environments. OBJECTIVE: To investigate the prevalence of OAS and seasonal allergic rhinitis (SAR) among Japanese children and evaluate the relationship between OAS and SAR. METHODS: We administered a questionnaire-based survey among children aged 7-15 years, living in 4 cities in central Japan. RESULTS: The questionnaires were administered to 4103 children and completed by 3365 (82.0%). Overall, 524 children (15.6%) reported OAS-like symptoms after ingesting fruits or vegetables. The prevalence of seasonal SAR and oral symptoms significantly differed among the 4 cities. The total prevalence of oral symptoms co-occurring with SAR was 24.4%, which was significantly higher than the prevalence of symptoms occurring without SAR (10.2%, p < 0.001). CONCLUSIONS: Herein, oral symptoms were more likely to occur in patients with SAR than in those without SAR. The prevalence of SAR and food-induced oral symptoms significantly differed among the regions, suggesting they might be affected by regional differences in lifestyles and flora.