Prevalence and trends of sensitisation to aeroallergens in patients with allergic rhinitis in Guangzhou, China: a 10-year retrospective study

Alternaria Allergy and Immunotherapy

BACKGROUND

Allergen immunotherapy (AIT) is the only known causative treatment for Alternaria allergy, but the difficulty in standardizing Alternaria extracts hampers its effectiveness and safety.

SUMMARY

Alternaria, a potent airborne allergen, has a high sensitization rate and is known to trigger the onset and exacerbation of respiratory allergies, even inducing fungal food allergy syndrome in some cases. It can trigger a type 2 inflammatory response, leading to an increase in the secretion of type 2 inflammatory cytokines and eosinophils, which are the culprits behind allergic symptoms. Diagnosing Alternaria allergy is a multistep process, involving a careful examination of clinical symptoms, medical history, skin prick tests, serum-specific IgE detection, or provocation tests. Alt a1, the major component of Alternaria, is a vital player in diagnosing Alternaria allergy through component-resolved diagnosis. Interestingly, Alternaria can reduce the protein activity of other allergens like pollen and cat dander when mixed with them. In order to solve the problems of standardization, efficacy and safety of traditional Alternaria AIT, novel AIT methods targeting Alt a1 and innovative vaccines such as epitope, DNA, and mRNA vaccines seem promising in bypassing the standardization issue of Alternaria extracts. But these studies are in early stages, and most researches are still focused on animal models, calling for more evidence to validate their use in humans.

KEY MESSAGES

This review delves into the various aspects of Alternaria allergy, including characteristics, epidemiology, immune mechanisms, diagnosis, clinical manifestations, and the application and limitations of Alternaria AIT, aiming to provide a foundation for the management of patients with Alternaria allergy.

Multicenter study of seasonal and regional airborne allergens in Chinese preschoolers with allergic rhinitis

This study is nationwide multicenter epidemiological research, aimed at investigating the distribution changes and seasonal patterns of various airborne allergens among preschool children with allergic rhinitis (AR) in different regions of China, and analyzing the clinical correlation between sensitization to various airborne allergens and AR symptoms in children. Information on children was collected through standard questionnaires, and total IgE (tIgE) and specific IgE (sIgE) for 11 inhalant allergens were tested. The results showed that dust mites are the primary allergens for preschool AR children (39%). Among pollen allergens, Amb a had the highest positivity rate (8.1%), followed by Art v (7.8%). The sensitization rates for two mites peaked in May (46.9% and 40.6%). Art v peaked in August (21.5%), while Amb a had peaks in May (12.7%) and August (17.8%). The sensitization peaks for various tree pollens mainly occurred in August. In the Eastern monsoon region, the sensitization rate to mites was significantly higher than in the Northwest arid and semi-arid regions; whereas, for pollen allergens, the sensitization rates to Amb a, Pla a, Pin a, Pop d, and Bet v were significantly higher in the Northwest arid and semi-arid regions than in the Eastern monsoon region. The correlation among various tree pollens, specifically between Pla a, Pin r, Pop d, and Bet v was strong (0.63 ~ 0.79), with a cross-overlapping percentage of 53.9%. Children with multiple pollen sensitizations had higher cumulative nasal symptom scores than those negative for pollen (P < 0.01). Children with only pollen sensitization had higher cumulative rhinitis symptom scores than the all-negative group (P < 0.0001) and the mite-only sensitization group [P < 0.05], while the mite-only sensitization group also had higher scores than the all-negative group [P < 0.05], and the group sensitized to both pollen and mites had lower scores than the pollen-only group [P < 0.05]. This study indicates that sensitization to mites and grass pollens exhibits significant regional differences, with grass pollen allergies primarily occurring in autumn, sensitization to pollens in general exhibits a pronounced seasonal pattern. Moreover, pollen sensitization aggravates nasal and ocular symptoms in AR children.

Prevalence of allergen sensitization among children with allergic rhinitis in Changzhou, China: a retrospective observational study

OBJECTIVE

To determine the prevalence of sensitivity to common inhaled and food allergens among children with allergic rhinitis (AR) in Changzhou in eastern China and provide a basis for epidemiological research of pediatric allergic rhinitis and allergen avoidance in this region.

METHODS

This was a retrospective observational study, a total of 1248 children with AR were enrolled at the Third People's Hospital of Changzhou between January 2018 and December 2019. The serum-specific immunoglobulin E (sIgE) to 19 kinds of inhaled and food allergens and serum total IgE were detected with the AllergyScreen test (Mediwiss Analytic GmbH, Moers, Germany). All participants had a positive reaction to at least one allergen in the test (the sIgE concentration ≥ 0.35 IU/ml).

RESULTS

Among the patients, 818 (65.54%) were male and 430 (34.46%) were female, with 81 (6.50%) aged 1-3 year, 501 (40.14%) aged 4-7 year, and 666 (53.36%) aged 8-14 year. The positivity rate of inhaled allergens was 80.05% (n = 999), while the positivity rate of food allergens was 66.19% (n = 826). 828 patients (66.35%) were sensitized to multiple allergens. The most common inhaled allergens were Dermatophagoides pteronyssinus (65.38%), mold mix (25.56%), house dust (20.67%), and dog hair dander (13.94%), and the most common food allergens were cow's milk (30.31%), cashew nut (27.9%), egg (22.68%), and beef (12.98%). With an increase in age, the inhaled allergen positivity rate showed a significant increase (P < 0.01), while the food allergen positivity rate decreased significantly (P < 0.01). There were significant age differences in total IgE levels (P < 0.01) and the total IgE level was highest in the group aged 8-14 year.

CONCLUSIONS

Dermatophagoides pteronyssinus was the most common sensitizing allergen in pediatric patients with AR in Changzhou. Several other inhaled and food allergens were also common. We observed that multiple allergenic factors play an important role in the occurrence and development of AR.

Novel insights into central compartment atopic disease - a literature review

INTRODUCTION

Central compartment atopic disease (CCAD) is a newly recognized variant subtype of chronic rhinosinusitis (CRS). Although CCAD has been reported to be correlated with allergy, there is still a considerable gap in our knowledge regarding CCAD.

AREAS COVERED

We have conducted a thorough analysis of the literature on CCAD. This review provides current understanding and therapeutic strategies of CCAD. In this article, we will review the clinical presentations and parameters, allergy-related etiology, endotypes, and recommended management of CCAD.

EXPERT OPINION

CCAD is considered as an aeroallergen-driven type 2/eosinophilic inflammatory pattern. Although CCAD can be diagnosed by endoscopy and radiology, as well as allergen test, pathogenesis and management strategies leave much to be desired, and further studies are needed.

Fungal Aeroallergen Sensitization Patterns among Airway-Allergic Patients in Zagazig, Egypt

BACKGROUND

Airway allergies such as asthma and allergic rhinitis, as well as their comorbidities, are increasing worldwide, causing significant socioeconomic health burdens to societies. It is estimated that between 3% and 10% of the population is allergic to fungi. The type of fungal sensitization varies from one geographical region to another. The present study aimed to identify the common fungal aeroallergen sensitization patterns among airway-allergic patients residing in the Zagazig locality, Egypt, in order to obtain a better understanding of fungal allergy, in addition to improving the awareness and management strategies for those patients.

METHODS

The present cross-sectional study included 200 allergic rhinitis and asthma patients. Sensitization to fungal aeroallergens was evaluated by skin prick testing and in vitro measurement of total and specific immunoglobulin E.

RESULTS

As determined by a skin prick test, 58% of the patients studied were allergic to mixed molds. Alternaria alternata was the predominant fungal aeroallergen among the studied patients (72.2%), which was followed by Aspergillus fumigatus (53.45%), Penicillium notatum (52.6%), Candida albicans (34.5%), and Aspergillus niger (25%).

CONCLUSION

Mixed mold sensitization ranked fourth among the most frequent aeroallergens in airway-allergic patients, and Alternaria alternata was the most frequently encountered fungal aeroallergen in the Zagazig locality.

Sensitization to Furry Animals in Patients with Suspected Allergic Disease in China: A Multicenter Study

PURPOSE

An objective of this study was to investigate the allergen sensitization characteristics of cat, dog and horse dander in patients with suspected allergic diseases in different geographical regions of Chinese mainland.

PATIENTS AND METHODS

We invited 2377 patients aged 0-86 years with suspected allergic diseases to participate in a cross-sectional survey in 11 provinces in China. Combined with the questionnaires and animal-specific IgE levels, we analyzed the epidemiological characteristics and risk factors of furry animal sensitization in different regions and populations of Chinese Mainland.

RESULTS

Among the 2377 patients with suspected allergic diseases, 14.9% were sensitized to cat dander, 9.3% to dog dander and 5.5% to horse dander. Animal allergens mainly cause low-level sensitization (class 1-3). There was a significant correlation between cat, dog and horse dander allergen sIgE, with correlation coefficients (rs) all greater than 0.750. The majority (46.5%) of sIgE-positive patients were sensitized to at least two animal allergens simultaneously. The prevalence of these animals all showed a trend of increasing first and then decreasing with age, and all reached the peak in young adolescence. As for the geographical factors, the sensitization rate of cats and dogs in Western was significantly higher than that in Eastern (cat: 18.4% vs 9.2%, dog: 11.6% vs 5.5%, all P < 0.001), however, no significant differences were found in horses. Aged ≤6 years, living in Western, and high animal allergen exposure elevated the risk of cat or dog sensitization. Living on a lower floor (aOR: 0.56) was a protective factor for horse sensitization.

CONCLUSION

In this representative sample of Chinese patients with suspected allergic diseases, there was an apparent geographic variation in sensitization to cats and dogs. Age factor and living in Western also had a significant impact on animal allergen sensitization rate.

Chinese Guideline on Allergen Immunotherapy for Allergic Rhinitis: The 2022 Update

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.

Epithelial barrier hypothesis: Effect of the external exposome on the microbiome and epithelial barriers in allergic disease

Environmental exposure plays a major role in the development of allergic diseases. The exposome can be classified into internal (e.g., aging, hormones, and metabolic processes), specific external (e.g., chemical pollutants or lifestyle factors), and general external (e.g., broader socioeconomic and psychological contexts) domains, all of which are interrelated. All the factors we are exposed to, from the moment of conception to death, are part of the external exposome. Several hundreds of thousands of new chemicals have been introduced in modern life without our having a full understanding of their toxic health effects and ways to mitigate these effects. Climate change, air pollution, microplastics, tobacco smoke, changes and loss of biodiversity, alterations in dietary habits, and the microbiome due to modernization, urbanization, and globalization constitute our surrounding environment and external exposome. Some of these factors disrupt the epithelial barriers of the skin and mucosal surfaces, and these disruptions have been linked in the last few decades to the increasing prevalence and severity of allergic and inflammatory diseases such as atopic dermatitis, food allergy, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, and asthma. The epithelial barrier hypothesis provides a mechanistic explanation of how these factors can explain the rapid increase in allergic and autoimmune diseases. In this review, we discuss factors affecting the planet's health in the context of the 'epithelial barrier hypothesis,' including climate change, pollution, changes and loss of biodiversity, and emphasize the changes in the external exposome in the last few decades and their effects on allergic diseases. In addition, the roles of increased dietary fatty acid consumption and environmental substances (detergents, airborne pollen, ozone, microplastics, nanoparticles, and tobacco) affecting epithelial barriers are discussed. Considering the emerging data from recent studies, we suggest stringent governmental regulations, global policy adjustments, patient education, and the establishment of individualized control measures to mitigate environmental threats and decrease allergic disease.

Chinese Central Compartment Atopic Disease: The Clinical Characteristics and Cellular Endotypes Based on Whole-Slide Imaging

Purpose

Histopathologic characterizations of central compartment atopic disease (CCAD) by whole-slide imaging remains lacking. We aim to study clinical presentations and cellular endotyping diagnosis of Chinese CCAD using artificial intelligence (AI).

Methods

A total of 72 patients diagnosed with chronic rhinosinusitis with nasal polyps (CRSwNP) were enrolled. CCAD was defined by positive result of serology specific IgE, endoscopic and radiological findings. The aeroallergen sensitization status, endoscopic results, radiological findings, and symptoms were evaluated and compared between patients with CCAD (n=14), eosinophilic CRSwNP (ENP, n=32) and non-eosinophilic CRSwNP (NENP, n=26). The cellular endotypes including eosinophils, neutrophils, lymphocytes, and plasma cells were analyzed by the AI chronic rhinosinusitis evaluation platform 2.0.

Results

CCAD was most common in male (71.43%). The positive rate of aeroallergen in patients with CCAD is 100%, which is much higher than those in patients with ENP (40.63%) and NENP (23.08%). Allergic rhinitis incidence was found to be 57.14% in Chinese CCAD subjects, which is obviously higher when compared with those in patients with ENP (21.88%) or NENP (0.00%). The presence of asthma was not significantly different between groups. Chinese CCAD population demonstrated mild symptoms and lower endoscopic and radiological scores than those in patients with ENP and NENP. For cellular endotypes in CCAD subjects, the median of eosinophils, neutrophils, lymphocytes, and plasma cells was 26.55%, 0.49%, 60.85%, and 7.33%, respectively. The proportion of eosinophils in nasal tissue and peripheral blood mononuclear cells from the CCAD group is between the proportions in those patients with ENP and NENP.

Conclusion

Chinese CCAD was associated with aeroallergen sensitivity, and displayed an eosinophil-dominant inflammatory pattern. Thus, proper management with allergy control and topical steroids could be recommended for CCAD treatment.

Environmental and sensitization variations among asthma and/or rhinitis patients between 2008 and 2018 in China

Background

Little is known about the changes in allergen sensitization in China secondary to the environmental variations over the past decade. We aimed at investigating the variations in sensitization among asthma and/or rhinitis patients in China between 2008 and 2018.

Methods

This study analyzed cross‐sectional data from national surveys conducted in China in 2008 and 2018. After finishing the questionnaire, participants underwent serum specific IgE measurements. A total of 2322 and 2798 patients were enrolled in 2008 and 2018, respectively. The significance of differences in sensitization rates among four regions of China were assessed. Correlation analysis was used to identify the associations of sensitization with climate change and planting of Artemisia desertorum between the two surveys.

Results

Compared with 2008, the general sensitization rate to mites significantly increased in 2018, which ranked highest among all tested allergens. Sensitization to pollens, especially Artemisia vulgaris, showed the greatest increase in the north. The annual mean temperature, rainfall and relative humidity in all four regions, and the Artemisia desertorum coverage in the northeastern area, increased significantly in 2018 as compared with 2008. From 2008 to 2018, an increase in Dermatophagoides pteronyssinus sensitization was significantly associated with an increase in relative humidity (r = 0.54, p = 0.037). The increase in A. vulgaris sensitization was significantly associated with the increase in the A. desertorum planting area (r = 0.67, p = 0.006) and with a decrease in rainfall (r = −0.59, p = 0.021).

Conclusions

House dust mites remain the most important allergen in Chinese individuals with asthma and/or rhinitis. Pollen sensitization dramatically increased in northern China. Increases in sensitization to dust mites and Artemisia were related to the increases in humidity and planting area of A. desertorum.

Prevalence of Sensitization to Aeroallergens in Greater Beijing Region Children With Respiratory Allergy

OBJECTIVE

To evaluate the prevalence and distribution of sensitization to aeroallergens in children with atopic diseases.

METHODS

We conducted skin prick test on 9,527 pediatric patients (aged 0-17 years) with atopic diseases in allergy department of Children's Hospital affiliated with the Capital Institute of Pediatrics. Positive rates of aeroallergens were compared among the different groups.

RESULTS

Boys (69.5%) had a higher positive rate in SPT results than girls (59.8%; χ² = 91.7, P < 0.01), and the prevalence of sensitization to aeroallergens increased from 56.1% in the 0-5 year group, to 73.0% in patients above 12 years. Japanese hop (36.2%) and D. farinae (28.1%) were the most common outdoor and indoor aeroallergens, respectively. From low to high age groups, the positive detection rates of D. farinae were 20.3, 30.6, and 33.5%, respectively, followed by D. pteronyssinus (15.7, 24.8, and 30.0%) and cat dander (8.6, 19.8, and 27.9%, respectively), while dog dander and cockroach showed the same trend. The top three positive detection rates of outdoor aeroallergens were Alternaria (30.9%), Japanese Hop (26.7%), and Artemisia (23.7%) in the preschool age group. With regard to patients aged 6 to 11 years, the three most common were Japanese hop (39.2%), Alternaria (36.4%), and Fraxinus pollen (34.4%). Japanese hop (43.8%), Sabina (41.1%), and birch pollen (39.6%) became increasingly common allergens among adolescents. There were more patients with strongly positive reactions to Alternaria in AS (χ² = 10.2, P < 0.01) and AS with AR groups (χ² =9.7, P < 0.01) than those in the AR group. Asthmatic patients had significantly higher multiple positive reactions than those with AR (P < 0.01). Asthmatic patients had a much higher prevalence of HDM, animal dander, and Alternaria than those with allergic rhinitis (P < 0.05).

CONCLUSION

The prevalence of sensitization to aeroallergens increased with age in children with atopic diseases in Greater Beijing Region. Alternaria was the predominant allergen before 5 years of age, and tree pollen had delayed sensitization in adolescents. Sensitization to perennial allergens such as HDM, cats, and Alternaria was more strongly associated with asthma risk. Sensitization to more than one allergen significantly affected asthmatic patients.

Cockroach exposure and its allergy sensitization in asthma patients

Asthma is a heterogeneous disease with distinct phenotypes. Serum tIgE, SSIgE and SPT are the methods of evaluating allergen sensitization. The present study evaluates the exposure and sensitization to cockroach (Periplaneta americana) antigens in asthma patients in a metropolitan city of India. The study enrolled 200 consecutive bronchial asthma patients, diagnosed as per GINA guidelines. As per history of exposure to cockroaches, the patients are divided in two groups as exposed and non-exposed asthmatic. All the enrolled subjects underwent SPT against common aeroallergens including cockroach, spirometry and estimation of tIgE level and SSIgE against cockroach. Out of 200 asthma patients, a total of 114 (57%) asthmatic were found SPT positive against one of the common aeroallergens, of which 68 (34%) showed SPT sensitivity against cockroach. A total of 103 (51.5%) patients were found exposed to cockroaches. In the cockroach exposed group, the mean serum tIgE was found significantly higher than the non-exposed group (569.31±224.64 vs 479.29±237 IU/ml; p=0.007). The mean SSIgE against cockroach in exposed groups was found not significant than non-expose group (4.87±11.19 vs 4.11±8.39 KUA/L; p=0.589). The mean tIgE was also not significant in atopic compared to non-atopic asthmatic (553.25±218.12 IU/ml vs 489.1±251.16 IU/ml; p=0.056). The mean SSIgE against cockroach was 5.66±10.45 KUA/L for atopic and 2.96±8.98 KUA/L for non-atopic (p=0.054). The airway obstruction was almost the same in both groups.  Asthmatic patients who were exposed to cockroach and atopic had high tIgE, SSIgE levels and SPT positivity against cockroach antigen compared to non-exposed patients.

Using the Internet Big Data to Investigate the Epidemiological Characteristics of Allergic Rhinitis and Allergic Conjunctivitis

Background

To explore the epidemiological characteristics of allergic rhinitis (AR) and allergic conjunctivitis (AC) based on the Internet big data.

Methods

The Baidu index (BDI) of keywords “allergic rhinitis” and “allergic conjunctivitis” in Mandarin, the daily pollen concentration (PC) released by the Beijing Meteorological Bureau and the volumes of outpatient visits (OV) of the Beijing Tongren Hospital (Beijing) and the Third Affiliated Hospital of Sun Yat-sen University (Guangzhou) from 2017 to 2020 were obtained. The temporal and spatial changes of AR and AC were discussed. The correlations between BDI and PC/OV were analyzed by Spearman correlation analysis.

Results

The trends of BDI of “AR”/“AC” in Beijing showed obvious seasonal variations, but not in Guangzhou. The BDI of “AR” and “AC” was consistent with the OV in both cities (r_1AR-BJ=0.580, P<0.001; r_1AR-GZ=0.360, P=0.031; r_1AC-BJ=0.885, P<0.001; r_1AC-GZ=0.694, P<0.001). The BDI of “AR” and “AC” was highly consistent with the change of the PC in Beijing (r _AR-Pollen=0.826, P<0.001; r _AC-Pollen=0.564, P<0.001). The OV of AR in Beijing and Guangzhou decreased significantly in the first half of 2020, but there was no significant change in AC. In the first half of 2020, the OV of AC in Beijing was significantly higher than that of AR, while that of AC in Guangzhou was slightly higher than that of AR.

Conclusion

The BDI could reflect the real-world situation to some extent and has the potential to predict the epidemiological characteristics of AR and AC. The BDI and OV of AR decreased significantly, but those of AC were still at a high level, during the COVID-19 pandemic, in the environment where most people in Beijing and Guangzhou wore masks without eye protection.

Developing nomograms for identifying allergic rhinitis among chronic rhinitis: A real-world study

Background

It is difficult to discriminate allergic rhinitis (AR) and nonallergic rhinitis (NAR) in clinical practice due to the similar clinical manifestations. The study was to assess both the demographical and clinical features of AR and NAR in the real-world data of outpatients in China.

Methods

It was a cross-sectional real-world study. AR and NAR were defined based on both subjective symptoms and objective specific serum IgE test. General demographic characteristics as well as clinical information were documented. Patients were further classified according the seasons of initial visiting hospital (during pollen seasons or not). A scoring system presented as nomograms for presence of AR was performed.

Results

In the pollen season group, age distribution, the duration of rhinitis, comorbidity of asthma, food allergies, and score of coughing were found significantly associated with AR. Additionally, in the non-pollen season group, we found that ethnicity, age distributions, duration of rhinitis, comorbidity of asthma, food allergies, and family history of allergy, together with scores of gritty eyes were associated factors of AR. Based on multivariate logistic model, we built two nomograms which included previously identified significant risk factors that could be acquired easily during clinical practice with predictive variables to assess their roles in predicting the risk of AR among outpatients with rhinitis.

Conclusions

The characteristics of patients with different phenotypes of chronic rhinitis are distinctive in different seasons and the developed nomogram in this study might be beneficial for clinical practice.

[Sensitization pattern of cat and dog dander allergen in 16 426 patients with allergic diseases]

Objective:To explore the sensitization feature of cat and dog dander and time trend in northern region. Methods:During year 2017 to year 2019, subjects with self-reported allergic diseases received skin prick test for cat and dog dander allergen. Skin index（SI） ≥2+ was considered as positive SPT. SI2+ was defined as mild sensitization, SI3+ was defined as moderate sensitization while SI4+ was defined as severe sensitization. The age and gender difference of sensitization rate between cat and dog dander allergen was analyzed. Meanwhile, the trend of cat and dog dander sensitization rate was analyzed. Results:Overall, 16 426 subjects were enrolled in this study. ① The sensitization rate of cat dander was significantly higher than dog dander（11.8% vs 6.0%, P<0.001）. Severe sensitization rate of cat dander was significantly higher than dog dander（5.9% vs 1.7%, P<0.001） while there was no significant difference of mild sensitization rate. ②Sensitization age of cat dander was younger than dog dander（P<0.001）. Sensitization rate of cat and dog dander was higher in subjects ≤18y compared with those >18y（20.2% vs 10.9%, P<0.001; 8.1% vs 5.7%, P<0, 001）. The highest sensitization rate was presented in 13-18y age group（27.3% vs 9.9%, P<0.001）, following by 7-12y age group（26.0% vs 9.2%, P<0.001）. Sensitization rate of cat dander was higher in male than in female（13.7% vs 10.7%, P<0.001） while no gender difference was observed in dog dander sensitization（6.2% vs 5.8%, P=0.411）. ③595 subjects（3.6%） were both sensitized to cat and dog dander while 1733 subjects（10.6%） were sensitized either to cat or dog dander. Single sensitization rate of cat dander was higher than single sensitization rate of dog dander（8.2% vs 2.3%, P<0.001）. There was a positive correlation between the cat and dog dander sensitization rate（r=0.386, P<0.001）. ④During 2017-2019, the sensitization rate of cat dander increased but without significantly statistic difference while dog dander sensitization rate was descending from 7.4% to 4.6% significantly（χ²=38.298, P<0.001）. Conclusion:Cat dander sensitization rate was higher than dog dander with a peak age in adolescence. A trend of rising for cat dander allergy and descending for dog dander allergy was observed during the past three years.

Asthma and allergic rhinitis among young parents in China in relation to outdoor air pollution, climate and home environment

We estimated associations between ambient air pollution, home environment and asthma as well as rhinitis among adults across China. A total of 40,279 young adults from eight Chinese cities participated in a questionnaire survey (participation rate 75%). There were questions on health and home environment. Information on city level gross domestic product (GDP) per capita, ambient temperature and PM₁₀ and NO₂ were collected from registers. Two-level logistic regression models were used to study health associations. Totally 1.6% reported asthma and 6.6% reported allergic rhinitis (AR). Higher temperature was associated with more asthma but less AR. Higher GDP was associated with less asthma but more AR. Higher degree of urbanization, higher level of NO₂ and living near heavily trafficked road were risk factors for asthma and AR. Participants in older buildings reported more asthma. Redecoration and buying new furniture were related to more asthma and AR (OR = 1.15-1.91). Using natural gas (OR = 1.34) and biomass (OR = 1.35) for cooking were risk factors for AR. Burning mosquito coils and incense increased the risk of asthma and AR. Cat keeping (OR = 2.88), dog keeping (OR = 2.04), cockroaches (OR = 1.54) and rats or mice (OR = 1.46) were associated with asthma. Cockroaches increased the risk of AR (OR = 1.22). Air humidifier and air cleaner were linked to asthma and AR. Frequent cleaning and exposing bedding to sunshine were protective. In conclusion, urbanization, NO₂ and traffic exhaust can increase the risk of adult asthma and AR. Higher ambient temperature was related to more asthma but less AR. Indoor animals such as cats, dogs, rats/mice and presence of cockroaches were associated with asthma or AR. Indoor chemical sources such as redecoration and new furniture were other risk factors. Cooking with natural gas or biomass and burning mosquito coils and incense were associated with asthma or AR. Frequent cleaning and exposing bedding to sunshine were protective.

China Consensus Document on Allergy Diagnostics

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.

Prevalence of Aeroallergens in Allergic Rhinitis in a Tertiary Care Hospital

INTRODUCTION

The prevalence of allergic rhinitis has increased significantly globally over the last two decades. Detection of sensitizing aeroallergens plays a crucial role in the diagnosis and management of this troublesome disease. This study aims to investigate the spectrum of aeroallergens sensitization in patients with allergic rhinitis in a tertiary care hospital.

METHODS

A descriptive cross-sectional study conducted in the Department of Otorhinolaryngology of our hospital between January 2016 to December 2019. Ethical approval was taken from the Institutional Review Committee (No: 210/19). Patients diagnosed with allergic rhinitis were enrolled using the convenience sampling technique. Data entry and analysis was done using IBM Statistical Package for Social Sciences version 20.0.

RESULTS

Among 170 patients, altogether 103 (60.6%) patients yielded positive responses on the skin prick test. The most prevalent aeroallergens were Lepidoglyphus 86 (50.60%), Dermatophagoides pteronyssinus 85 (50%), Dermatophagoides farina 82 (48.20%), Thyrophagus 50 (29.40%), Blomia 46 (27.10%), Acarus 43 (25.30%), cat dander 26 (15.30%), dog dander 24 (14.10%), cow and buffalo dander 20 (11.8%), ragweed 20 (11.8%), grass pollen 18 (10.60%) and mugwort 17 (10%).

CONCLUSIONS

This study highlights that the frequency of aeroallergens based on skin prick test in patients presenting to a tertiary care hospital which showed the dominance of house dust mites, dog and cat hair, pollen, and grasses. Reduced exposure and training of patients about protection against these agents will possibly help in controlling the severity of allergic rhinitis in this region.

Major Pollen Allergen Components and CCD Detection in Bermuda Grass Sensitized Patients in Guangzhou, China

Objective

Bermuda grass pollen is a common inhaled allergen. The aim of this study was to investigate the molecular sensitization patterns to major pollen allergens (Bermuda grass, Mugwort and Timothy grass) and cross-reactive carbohydrate determinants (CCD) in Bermuda grass sensitized patients in southern China.

Methods

Serum specific IgE (sIgE) levels of Bermuda grass allergen components (Cyn d 1 and Cyn d 12), Timothy grass allergen components (Phl p 1, Phl p 4, Phl p 5, Phl p 7 and Phl p 12), Mugwort allergen components (Art v 1, Art v 3 and Art v 4) and CCD were detected in 78 patients sensitized to Bermuda grass via EUROBlotMaster system.

Results

Compared with CCD-positive patients, those with negative CCD results had significant higher positive rates of Cyn d 1 (47.8% vs 14.5%), Phl p 1 (26.1% vs 7.3%), Phl p 12 (21.7% vs 3.6%) and Art v 4 (26.1% vs 3.6%) (all p < 0.05). Patients <18 years old had the highest positive rate of Cyn d 1 (40.7%). Additionally, rhinitis patients had the highest positive rate of Cyn d 1 (60.0%), and all patients with Cyn d 12 sensitization (17.2%) were asthmatic patients. Optimal scale analysis showed that Phl p 1 and Cyn d 1 were closely related (Cronbach’s alpha = 85.1%).

Conclusion

The highest positive rate of pollen allergen components was Cyn d 1 in Bermuda grass sensitized patients in southern China. Most patients were sensitized to CCD alone, and CCD may have less interference in the detection of Cyn d 1, Art v 4, Phl p 1 and Phl p 12. The sensitization patterns of pollen allergen components varied in different ages and diseases, and the diagnostic strategy of pollen allergen needs to be considered in the future.

Sensitization to Furry Animals and Clinical Relevance of House Dust Mite-Induced Allergic Rhinitis in Guangzhou, China

INTRODUCTION

The impact of furry animal allergens on house dust mite (HDM)-induced allergic rhinitis (AR) is unclear.

OBJECTIVE

We aimed to investigate the co-sensitization and cross-sensitization of furry animal allergens and assess their clinical relevance with HDM-induced AR.

METHODS

We enrolled 268 patients with HDM-induced AR who were diagnosed with skin prick tests positive for dogs and/or cats. Specific immunoglobulin E (sIgE) for dogs (e1) and cats (e2), their components (Can f 1-5 and Fel d 1-2), and other uncommon furry animal extracts were measured. Symptoms and quality of life were assessed with a visual analog scale (VAS).

RESULTS

The VAS scores for the AR and asthma (AS; n = 166), moderate-to-severe persistent-AR (n = 132), and e1P (positive)-e2P (n = 89) groups were higher than those for single AR (n = 102), other AR classifications, and other AR sensitization profiles, respectively. The IgE positivity rates for components such as Can f 1-3 and Fel d 2 and those for rats, sheep, mice, cows, and horses were highest in e1P-e2P patients. Can f 1-4, Fel d 1, Fel d 2, or the combined allergens were positively correlated with VAS scores. AR combined with AS and sensitization to Can f 4, Fel d 1, or mice were risk factors for HDM-induced AR with VAS scores ≥5.

CONCLUSIONS

Extensive cross-sensitization or co-sensitization was found between Can f 1-3, Fel d 2, or rat, sheep, mouse, cow, and horse extracts. Higher sIgE levels for Can f 1-4 and Fel d 1-2 or a higher number of furry animal allergens lead to more severe symptoms and a reduced quality of life. Combined with AS, sensitization to Can f 4, Fel d 1, or mice were risk factors for moderate-to-severe HDM-induced AR.

Does Air Filtration Work for Cat Allergen Exposure?

PURPOSE OF REVIEW

The goal of this review is to compress all important information and results of the research in reducing cat allergen exposure using air filtration. Fel d 1 is the major allergen responsible for IgE responses in 90 to 95% of patients with cat allergy.

RECENT FINDINGS

Reduction of cat allergen in indoor air with different air filtration systems and portable devices has been demonstrated in the majority of the studies. Recently, early and late asthmatic responses were significantly reduced using portable HEPA air cleaners in an environmental exposure chamber. This review provides a comprehensive overview of the current state of airborne Fel d 1 air filtration targeting the most efficient devices in cat allergen reduction. Novel emerging HEPA filters are targeting reduction of cat indoor asthma trigger so patient can might benefit from efficient solution.

Principles of Allergen Immunotherapy and Its Clinical Application in China: Contrasts and Comparisons with the USA

Allergen immunotherapy (AIT) for allergic rhinitis (AR), asthma, and other allergic diseases has developed quickly. House dust mite (HDM), Artemisia (wormwood), Humulus japonicus (Japanese hop), Alternaria alternata, and Cladosporium herbarum are the five most common inhalant allergens in China. AIT has been performed in China for over 60 years. With the support of the Chinese Medical Association (CMA) and the Chinese Medical Doctors Association (CMDA), the Chinese College of Allergy and Asthma (CCAA) was established in 2016 as a specialized branch of CDMA and is the main certification authority for AIT. Chinese allergists and scientists have made tremendous progress in the development of AIT. There have been many publications by Chinese allergists and scientists worldwide encompassing original research studies, systematic reviews, case studies, and clinical trials. Currently, conventional subcutaneous immunotherapy (SCIT) is the preferred AIT in China, but sublingual immunotherapy (SLIT) is beginning to gain recognition. An increasing number of clinical trials have been conducted to investigate the clinical efficacy and side effects of SLIT and SCIT. In China, HDM is the only commercial standardized allergen extracts in clinical use, whereas the others are crude allergen extracts. Besides standardized allergen extracts, other forms of hypoallergenic extracts are still being investigated and developed in China. Immunotherapy in China is similar to that in the USA in which allergen extracts can be mixed for SCIT. However, allergen extracts cannot be mixed for SCIT in Europe.

Distribution and Determinants of Dermatophagoides Mites Sensitization ofAllergic Rhinitis and Allergic Asthma in China

BACKGROUND

The implementation of allergen immunotherapy (AIT) requires extensive knowledge of allergen distribution in the region to identify high-risk regions for AIT utilization. However, the geographical distribution patterns of the major Dermatophagoides allergens in China remain unclear despite the increasing prevalence of these allergens.

METHODS

We performed comprehensive database searches of articles demonstrating the distribution patterns of Dermatophagoides-sensitized allergic rhinitis (AR) and allergic asthma (AA) in China, published between 1990 and 2017.

RESULTS

We retrieved 163 articles encompassing 114,302 allergen-positive cases to generate the distribution maps. The rate of sensitization to Dermatophagoides pteronyssinus(D. pteronyssinus)and Dermatophagoides farinae (D. farinae) was similar in patients with AR (75.1 vs. 75.2%, p > 0.05) but not in those with AA (78.5 vs. 77.7%, p = 0.041). Patients with AR and AA shared similar regional distribution patterns of both D. pteronyssinus and D. farinae sensitization, which were highest in the southern and central parts of China and lowest in the northern regions, especially in the Northwest. The overall rate of sensitization to D. pteronyssinus and D. farinae was significantly higher in patients with AA (p < 0.001). Additionally, the annual mean temperature and humidity were the 2 major determinants of D. pteronyssinus and D. farinae sensitization in AR and of D. pteronyssinus sensitization in AA, whereas the annual mean temperature was the sole determinant for D. farinae sensitization in AA.

CONCLUSION

These findings may inform clinicians of the strategies for the prevention of Dermatophagoides sensitization and may be of benefit to the future clinical management of allergic diseasesassociated with sensitization to Dermatophagoides mites.

House Dust Mite Allergy Under Changing Environments

Environmental variations induced by industrialization and climate change partially explain the increase in prevalence and severity of allergic disease. One possible mechanism is the increase in allergen production leading to more exposure and sensitization in susceptible individuals. House dust mites (HDMs) are important sources of allergens inducing asthma and rhinitis, and experimentally they have been demonstrated to be very sensitive to microenvironment modifications; therefore, global or regional changes in temperature, humidity, air pollution or other environmental conditions could modify natural HDM growth, survival and allergen production. There is evidence that sensitization to HDMs has increased in some regions of the world, especially in the subtropical and tropical areas; however, the relationship of this increase with environmental changes is not so clear as has reported for pollen allergens. In this review, we address this point and explore the effects of current and predicted environmental changes on HDM growth, survival and allergen production, which could lead to immunoglobulin E (IgE) sensitization and allergic disease prevalence. We also assess the role of adjuvants of IgE responses, such as air pollution and helminth infections, and discuss the genetic and epigenetic aspects that could influence the adaptive process of humans to drastic and relatively recent environmental changes we are experiencing.

Increasing Prevalence of Allergic Rhinitis in China

Allergic rhinitis (AR) is a critical public health, medical and economic problem in China. AR is also an important risk factor which will cause many diseases or disorders, especially in children. The trend of AR incidence is still on the rise in recent years and has had a significant effect on the general public. This significant increase is alarming, which highlights an urgent need for better understanding of the prevalence status and characteristics, sensitization patterns, and the associated risk factors of AR in order to improve treatment and develop effective prevention strategies.

Effect of Cellulose Powder on Human Nasal Epithelial Cell Activity and Ciliary Beat Frequency

BACKGROUND

Cellulose powder (CP) has been reported as a safe and effective complementary treatment for allergic rhinitis (AR). Currently, CP has gained increasing application for clinical management worldwide, particularly in China. However, studies focusing on the effect of CP on normal human nasal epithelial cells (hNECs) and ciliary function are lacking. Here, we aimed to explore the adverse effects of CP on the activity and ciliary function of hNECs.

METHODS

We biopsied ethmoid sinus or middle turbinate tissues during surgical resection from control subjects who underwent endoscopic sinus surgery for diseases other than AR. Cells were isolated and passaged, followed by differentiation in an air-liquid interface (ALI). Flow cytometry and cell viability test (cell counting kit-8) were performed to detect the cytotoxicity of CP (effects on cell proliferation) on normal hNECs. By using the ALI culture model, we investigated the effects of CP on ciliary beat frequency (CBF).

RESULTS

There was a significant reduction in hNEC count at high concentrations of CP (2.5 mg/mL) at days 3 and 7 (both p < 0.05). As the concentration increased, cell death increased progressively from day 3 to day 7. However, these effects were not evident at low concentrations (0.25 mg/mL, p > 0.05). High-dose CP (2.5 mg) significantly reduced the CBF (p < 0.05). At lower concentrations (0.25-2.5 mg/mL), CP initially increased but subsequently reduced the CBF of hNECs compared with control group.

CONCLUSIONS

Cytotoxicity and the suppression of ciliary beat at high concentrations justify more prudent use of CP for the management of AR.

Effect of continuous positive airway pressure on allergic rhinitis in patients with obstructive sleep apnea-hypopnea syndrome

BACKGROUND

The effect of continuous positive airway pressure (CPAP) on nasal symptoms in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) remains controversial. In addition, possible mechanism(s) remains unclear.

OBJECTIVE

To examine whether CPAP contributes to the onset and exacerbation of allergic rhinitis (AR) in OSAHS patients based on patient-reported changes in nasal symptoms with and without CPAP therapy and the detection of house dust mites (HDMs) in CPAP filters and household environments.

MATERIALS AND METHODS

In a cohort of OSAHS patients, 350 patients who were undergoing CPAP therapy and 100 patients who declined CPAP therapy were retrospectively analyzed. These patients were contacted by telephone and asked to compare their nasal symptoms before and after CPAP therapy. HDMs in air conditioner and CPAP device filters and in household dust samples were detected using enzyme-linked immunosorbent assays.

RESULTS

The prevalence of AR was higher in the CPAP group vs the non-CPAP group (15.8% vs 7.0%, respectively; P = 0.025). The onset of AR among the OSAHS patients with no previous history of AR significantly increased within the first year of CPAP therapy compared with the control group (5.7% vs 0%, respectively; P = 0.031). Meanwhile, the patients with a history of AR were more likely to experience exacerbated rhinitis symptoms within the second year of treatment compared with the control group (7.5% vs 0%, respectively; P = 0.005). There was no significant difference in HDM concentrations between the CPAP and air conditioner filters, yet the concentrations in both the filters were higher than the concentrations in the bedroom dust samples (all P < 0.05).

CONCLUSION

CPAP is associated with the onset and exacerbation of AR in OSAHS patients. Long-term exposure to high concentrations of HDM allergens may be a significant factor.

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

A 10-year retrospective study of alterative aeroallergens sensitization spectrum in urban children with allergic rhinitis

Objective

To investigate the alterative spectrum and trends of aeroallergens sensitization in children with allergic rhinitis (AR) in Guangzhou, China in the past 10 years.

Participants and methods

In this retrospective study, 4,111 children with complaints of nasal hyper-reactivity who visited the Pediatric Department and/or Otolaryngology Department from January 2007 to November 2016 were enrolled. Serum specific immunoglobulin E was measured and positive detection was made in 3,328 patients, who were, therefore, diagnosed with AR. Positive rates and trends of different aeroallergens sensitization were assessed. The tendency of positive rates changing over the years, and the difference and trends in positive rate of aeroallergen sensitization that occurred in subgroups of gender, age, and season were determined and analyzed with logistic regression.

Results

The percentage of detected common aeroallergens in AR children was (from high to low) 81.07%, 34.44%, 14.72%, 11.81%, 6.04%, and 3.70% for house dust mites (HDMs), cat-dog dander, cockroach, mold mixture, tree pollen mixture, and herb pollen mixture, respectively. An ascending trend of aeroallergens sensitization or AR (odds ratio [OR] =1.116, 95% CI: 1.086-1.146) was found. Interestingly, an increasing trend of cat-dog dander and mold sensitization was found in AR children (OR =1.164, 95% CI: 1.133-1.196; OR =1.169, 95% CI: 1.120-1.223) in this retrospective study, while HDMs sensitization held a steady trend (OR =0.983, 95% CI: 0.961-1.007).

Conclusion

In the increasing trend of aeroallergens sensitization or AR, HDMs sensitization still held the majority. But emphasis should be made on pet allergy for young children with AR in the context of ascending trend of sensitization to cat-dog dander.

Eight Aeroallergen Skin Extracts May Be the Optimal Panel for Allergic Rhinitis Patients in Central China

BACKGROUND

The prevalence of allergic rhinitis (AR) is increasing rapidly in Central China. The skin prick test (SPT) is the standard tool with which to determine the allergen sensitization status in AR patients. Changes in allergen sensitization patterns have been observed within countries and regions due to geographical and seasonal variations.

OBJECTIVE

The aim of this study was to evaluate the profile of SPT reactivity to different aeroallergens in AR patients and to suggest a minimal panel of allergens to detect sensitized patients in Central China.

METHODS

From January 2015 to December 2016, patients who presented to Tongji Hospital with suspected AR were tested with the same panel of 19 aeroallergens. The results of SPT were analyzed to determine the minimum test battery panel necessary to cover 99% of the cases of SPT sensitization in different age subgroups.

RESULTS

A total of 2,416 patients (male:female ratio 1.2:1) were enrolled in our study with an average age of 22.0 years. The overall rate of sensitization to any allergen was 79.0%, and 64.3% of the subjects were monosensitized. The highest sensitized rate was found in the subgroup aged 14-18 years (92.0%), followed by the subgroups of 6-14 years (86.4%), >18 years (75.6%), and ≤6 years (74.9%). The most common sensitization was to Dermatophagoides farinae (71.1%). Testing with 8 allergens (D. pteronyssinus, D. farinae, Platanus, Artemisia, Cryptomeria, Blatella germanica, Humulus, and Alternaria) was sufficient to identify over 99% of the sensitized patients.

CONCLUSION

An SPT panel covering 8 allergen extracts was able to detect almost all sensitized patients suffering from AR symptoms in Central China.