Prevalence of respiratory and atopic disorders in Chinese schoolchildren

Climate change from the Asia-Pacific perspective: What an allergist needs to know and do

Allergic diseases such as asthma, atopic dermatitis, and food allergies are a burgeoning health challenge in the Asia-Pacific region. Compounding this, the region has become increasingly susceptible to the impacts of climate change. The region has weathered extreme precipitation, intense heat waves, and dust storms over the recent decades. While the effects of environmental and genetic factors on allergic diseases are well understood, prevailing gaps in understanding the complex interactions between climate change and these factors remain. We aim to provide insights into the various pathways by which climate change influences allergic diseases in the Asia-Pacific population. We outline practical steps that allergists can take to reduce the carbon footprint of their practice on both a systemic and patient-specific level. We recommend that allergists optimize disease control to reduce the resources required for each patient's care, which contributes to reducing greenhouse gas emissions. We encourage the responsible prescription of metered dose inhalers by promoting the switch to dry powder inhalers for certain patients, at each clinician's discretion. We also recommend the utilization of virtual consultations to reduce patient travel while ensuring that evidence-based guidelines for rational allergy management are closely adhered to. Finally, eliminating unnecessary testing and medications will also reduce greenhouse gas emissions in many areas of medical care.

Disparities in pediatric anaphylaxis triggers and management across Asia

BACKGROUND

The epidemiology and management of anaphylaxis are not well-reported in Asia.

METHODS

A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared.

RESULTS

Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao.

CONCLUSIONS

The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific.

Time-trends for eczema prevalences among children and adults from 1985 to 2015 in China: a systematic review

Background

Several studies have reported that childhood prevalence of eczema has been increasing worldwide. However, none study quantitatively evaluated prevalence trends of eczema among children and adults in the last 30 years in China.

Methods and Findings

Via a systematic review of literature databases in English and Chinese, we summarized all studies reporting eczema prevalences from 1985 to 2015 in China as well as diagramed prevalence and eczematous population trends against year for different age groups. A total of 93 studies and 17 studies (16 for children and one for adults) were selected for qualitative and quantitative synthesis, respectively. Childhood lifetime-ever eczema prevalences ranged from 10.0% to 30.0%. Prevalences among 3-12-year-olds children showed increasing trends in most specific cities, but national lifetime-ever eczema prevalences among 13-14-year-olds children decreased from 10.6% in 2001 to 8.6% in 2009 in mainland China. We estimated that about 1.5 million children aged 13-14-year-olds in 2009 and 15.5 million children aged 3-6-year-olds in 2012 had lifetime-ever eczema in mainland China. Similar studies were too few to ascertain time-trends of eczema prevalence among adults. About 39.4, 20.0, and 11.6 million adults aged 15-86-year-olds in 2010 had contact dermatitis, seborrheic dermatitis, and atopic dermatitis in the mainland China, respectively.

Conclusions

The burden of eczema became heavier in young children, whereas perhaps had been reduced in adolescent in China. More studies for eczema prevalence in adults are warranted.

Temporal Dynamics of the Nasopharyngeal Microbiome and its Relationship with Childhood Asthma Exacerbation

Despite distinct nasopharyngeal microbiome (NPM) profiles between asthmatics and healthy subjects, little is known about the NPM dynamics and its relation to childhood asthma exacerbation (AE). We investigated NPM changes by longitudinally collecting 135 flocked nasopharyngeal swabs (FNPSs) from 33 school-age asthmatic children at six time points (2 to 4-week intervals) from September to December 2017 in Hong Kong. Subjects were categorized into AE and stable asthma (AS) groups according to whether they experienced any exacerbation during follow-up. One-off FNPSs from nine nonasthmatic children were included as controls. Microbiota profiles were analyzed using 16S rRNA gene sequencing. All 144 NPMs were classified into six microbiome profile groups (MPGs), each dominated by Moraxella, Corynebacterium 1, Dolosigranulum, Staphylococcus, Streptococcus, or Anoxybacillus. The microbial diversity and compositions of NPM in exacerbation samples were different from both baseline samples and those from healthy controls. Moraxella and Dolosigranulum-dominated NPM exhibited high temporal stability revealed by MPG transition analysis. NPM diversity decreased whereas microbial composition remained similar over time. The relative abundances of Moraxella increased while Corynebacterium 1, Anoxybacillus, and Pseudomonas decreased longitudinally. However, these temporal patterns did not differ between AE and AS groups, suggesting that short-term dynamic patterns were not sufficient to predict AE occurrence. Asthmatic NPM underwent Moraxella expansion during AE and presented a high microbiome resilience (recovery potential) after AE resolution. Microbial pathways involved in methane, ketone bodies, and vitamin B3 metabolisms were enhanced during AE and primarily contributed by Moraxella. IMPORTANCE Evidence on the dynamic changes of NPM in asthmatic patients remains limited. Here, we present that asthmatic NPMs deviating from a healthy status still showed resilience after disturbance. Our data imply from a longitudinal perspective that Moraxella increase is closely related to AE occurrence. The finding of functional dysbiosis (imbalance) during AE offers a plausible explanation for the known association between nasopharyngeal Moraxella expansion and increased AE risk. This work serves as a basis for future long-term prospective studies leveraging multiomics approaches to elucidate the temporal association between NPM and pediatric AE.

[Analysis of inhalation allergen of patients with allergic rhinitis in Shenzhen]

Objective:To analyzed allergens and screen for common airborne allergens in patients with allergic rhinitis （AR） in Shenzhen, and identified the distribution pattern of allergens in this region. We aimed to provide scientific and feasible statistical and clinical basis for prevention and treatment of allergenic rhinitis. Methods:For 3351 suspected cases of allergenic rhinitis, 18 kinds of airborne allergen serum-specific IgE were determined using a detection system of BioSciTec GmbH company, and statistical analysis was carried out according to sex, age, severity and seasonal allergen. Results:A total of 3,351 cases with allergic rhinitis were positive for airborne allergens. The top five inhalation allergens were Blomia tropicalis （2231, 66.6%）, Dermatophagoides pterronyssinus （2212, 66.0%）, Dermatophagoides farinae （1986, 59.3%）, Cockroach （967, 28.9%）, and Short ragweed （844, 25.2%）. For the severity of the allergen, Dermatophagoides pterronyssinus ≥ level 3 accounted for 41.3% （1385/3351 cases） and Dermatophagoides farinae ≥level 3 accounted for 40.6% （1360/3351 cases）. Blomia tropicalis were classified as level 2, and other allergens were mainly classified as level 1 or 2. The detection rate among different age groups and gender is significantly different. Conclusion:The main airborne allergens in Shenzhen were Blomia tropicalis, Dermatophagoides pterronyssinus, Dermatophagoides farinae, Cockroach, as well as Short ragweed. The distribution of allergens was affected by sex, age and season.

Trends in the Epidemiology of Allergic Diseases of the Airways in Children Growing Up in an Urban Agglomeration

The prevalence of asthma and allergies among children has become an increasing problem in the last few decades. Data on the population of children and adolescents, especially living in polluted cities, are limited and based on studies carried out in small groups. In our study, we analyzed the incidence of asthma and allergic rhinitis between 2014 and 2018. We analyzed data collected from nearly 30,000 children aged seven to eight and adolescents aged 16–17, which allowed us to assess the frequency of allergic diseases in the population of children and youth in Krakow. More than 40% of respondents reported allergic symptoms, and nearly 50% of them were not diagnosed and treated. In the group of seven- and eight-year-olds with a positive history of allergies, 52% had allergic rhinitis and 9.1% had asthma. In the group of 16–17-year-olds, allergic rhinitis was diagnosed in 35.8%, while asthma was found in 4.9% of cases. The results obtained over the course of 10 years has shown the reduction in the frequency of asthma (from 22% in the case of asthma in both age groups) and allergic rhinitis cases (from 63.9% in adolescents). In our opinion, this can be considered a positive effect of the preventive measures taken in Kraków after 2010. Although there is still a higher incidence of allergic diseases among children and young people living in urban areas compared to rural areas, the trend apparently has reversed for some diseases.

Investigation of the allergens in 2,316 children with allergic rhinitis from Guangdong, China

Allergic rhinitis (AR) is one of the popular childhood diseases, bringing physical and metal burdens to the children and their families. The study was performed to detect common allergens eliciting AR in children, to investigate the prevalence of allergens in different age and gender cohorts, and to provide a reliable basis for clinical prevention and treatment of AR during childhood. We measured serum-specific IgE and performed inhalant and ingestion allergen examinations in 2,316 children with AR, in collaboration with BioSciTec GmbH. The prevalence of different allergens was determined according to gender, age, severity, and season. Among the 2,316 AR cases, the top five inhalant allergens were Dermatophagoides pteronyssinus (1,674 cases, 72.3%), Dermatophagoides farinae (1,520 cases, 65.6%), Blomia tropicalis (1,477 cases, 63.8%), Cockroach (602 cases, 26.0%), and Dog hair (602 cases, 26.0%). The top five ingestive allergens were Milk (1,111 cases, 48.0%), Egg white (543 cases, 23.4%), Shrimp/Crab (425 cases, 18.4%), Beef/Mutton (422 cases, 18.2%), and Egg yold (329 cases, 14.2%). AR severity analyses showed that 50.9% (1,180 cases) of D. pteronyssinus allergies were above level three, 47.9% (1,109 cases) of D. farinae allergies were above level three, only 23.3% (539 cases) of B. tropicalis allergies were level three, and B. tropicalis allergies were mainly of level 2. Other AR-inducing allergens mainly produced level one or two reactions. Regarding ingestion allergens, 7.9% (183 cases) of milk allergies and 4.7% (108 cases) of Shrimp/Crab allergies were above level three, and other allergens induced AR mainly of level one or two. The study investigated the major allergens eliciting AR in children from Guangdong, China, assessed the prevalence and severity among cohorts regarding age, gender, and season, and produced essential information on childhood AR, laying important references for AR prevention and treatment in the future.

Impact of Snoring on Telomere Shortening in Adolescents with Atopic Diseases

Atopic diseases can impose a significant burden on children and adolescents. Telomere length is a cellular marker of aging reflecting the impact of cumulative stress exposure on individual health. Since elevated oxidative stress and inflammation burden induced by chronic atopy and snoring may impact telomere length, this study aimed to investigate whether snoring would moderate the relationship between atopic diseases and telomere length in early adolescence. We surveyed 354 adolescents and their parents. Parents reported the adolescents' history of atopic diseases, recent snoring history as well as other family sociodemographic characteristics. Buccal swab samples were also collected from the adolescents for telomere length determination. Independent and combined effects of atopic diseases and snoring on telomere length were examined. Among the surveyed adolescents, 174 were reported by parents to have atopic diseases (20 had asthma, 145 had allergic rhinitis, 53 had eczema, and 25 had food allergy). Shorter TL was found in participants with a history of snoring and atopic diseases (β = -0.34, p = 0.002) particularly for asthma (β = -0.21, p = 0.007) and allergic rhinitis (β = -0.22, p = 0.023). Our findings suggest that snoring in atopic patients has important implications for accelerated telomere shortening. Proper management of atopic symptoms at an early age is important for the alleviation of long-term health consequences at the cellular level.

Effects of Sublingual Duster Mite Drops on Lung Function and Exhaled Nitric Oxide in Children with Multiple and Single Allergic Respiratory Diseases

Objective

To evaluate the efficiency of sublingual immunotherapy with Dermatophagoides Farinae Drops in children with single and multiple respiratory allergic diseases.

Methods

Seventy-one children with allergic respiratory diseases who had been treated with Dermatophagoides Farinae Drops for one year or more were divided into a single allergic group (12 cases) and multiple allergic group (59 cases). The rhinitis score, daytime and night symptom score of asthma, VAS score, drug score, pulmonary function, and FeNO level before and after treatment were evaluated and compared between the two groups.

Results

The rhinitis score, night symptom score, VAS score, and drug score in the single allergic group after treatment were significantly lower than those before treatment (p < 0.05), but there was no significant difference in the daytime symptom score before and after treatment (p > 0.05). The rhinitis score, VAS score, and drug score in the multiple allergic group after treatment were significantly lower than those before treatment (p < 0.05), but there was no significant difference in the scores of daytime symptoms and nighttime symptoms before and after treatment (p > 0.05). In both the single allergic group and multiple allergic group, the pulmonary function indexes of the patients were significantly improved after treatment, and the FeNO after treatment was significantly lower than that before treatment (p < 0.05). There was no significant difference in scores, pulmonary function, and FeNO between the two groups (p > 0.05).

Conclusion

Sublingual specific immunotherapy is effective in treating multiple and single allergic respiratory diseases in children.

The Active Compounds and Therapeutic Mechanisms of Pentaherbs Formula for Oral and Topical Treatment of Atopic Dermatitis Based on Network Pharmacology

To examine the molecular targets and therapeutic mechanism of a clinically proven Chinese medicinal pentaherbs formula (PHF) in atopic dermatitis (AD), we analyzed the active compounds and core targets, performed network and molecular docking analysis, and investigated interacting pathways. Information on compounds in PHF was obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and target prediction was performed using the Drugbank database. AD-related genes were gathered using the GeneCards and Online Mendelian Inheritance in Man (OMIM) databases. Network analysis was performed by Cytoscape software and protein-protein interaction was analyzed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources were applied for the enrichment analysis of the potential biological process and pathways associated with the intersection targets between PHF and AD. Autodock software was used to perform protein compound docking analysis. We identified 43 active compounds in PHF associated with 117 targets, and 57 active compounds associated with 107 targets that form the main pathways linked to oral and topical treatment of AD, respectively. Among them, quercetin, luteolin, and kaempferol are key chemicals targeting the core genes involved in the oral use of PHF against AD, while apigenin, ursolic acid, and rosmarinic acid could be used in topical treatment of PHF against AD. The compound–target–disease network constructed in the current study reveals close interactions between multiple components and multiple targets. Enrichment analysis further supports the biological processes and signaling pathways identified, indicating the involvement of IL-17 and tumor necrosis factor signaling pathways in the action of PHF on AD. Our data demonstrated the main compounds and potential pharmacological mechanisms of oral and topical application of PHF in AD.

Children's Respiratory Infections in Tianjin Area, China: Associations with Home Environments and Lifestyles

Children spend most of their indoors time at home, which may have substantial influence on their health. We conducted a cross-sectional study in the Tianjin area, China to quantify the incidence of respiratory infections among children, and its association with home environments and lifestyles. The lifetime-ever incidences of croup, pneumonia and ear infection among children aged 0-8 in Tianjin area was 9.2%, 28.7% and 11.6%, respectively. The incidence of common cold infections more than twice per year was 31.3%. Home environments and lifestyles included strong risk factors for childhood respiratory infections. Perceived dry air had the greatest association with childhood common colds (population attributable fraction (PAF = 15.0%). Modern floor covering had the greatest association with croup (PAF = 14.7%) and ear infection (PAF = 34.5%), while infrequent bedding sun-curing had the greatest association with pneumonia (PAF = 18.7%). Condensation (a proxy of poor ventilation) accounted for 12.2% of the incidence of croup (PAF = 12.2%) and frequent common colds (PAF = 8.4%). Our findings indicate that factors related to "modern" home environments and lifestyles are risks for childhood respiratory infections. Modifying such factors might reduce the incidence of respiratory infections among children.

The effectiveness of sublingual immunotherapy for house dust mite-induced allergic rhinitis and its co-morbid conditions

Aim: We investigated sublingual immunotherapy for mite-induced allergic rhinitis and its comorbid allergic conditions. Patients & methods: A prospective case-controlled study of 120 patients (case = 80, control = 40) over 12 months. Results: There was 53.6% reduction in total rhinitis symptom score (p < 0.0001), but not in controls (-7.3%, p = 0.99). The total symptom scores for concurrent asthma decreased from 17.79 to 8.8 (p < 0.0001); for allergic conjunctivitis from 20.89 to 10.0 (p = 0.0002); for atopic dermatitis from 46.40 to 29.38 (p = 0.0004) and 74.6% of patients weaned off nasal topical steroids. The treatment-related adverse reactions were mild and self-limiting. Conclusion: Though sublingual immunotherapy may be more expensive than conventional treatments, it was an adjunctive therapy that improved not only the outcomes for allergic rhinitis, but also its comorbid allergic conditions.

Efficacy and safety of sublingual immunotherapy with Dermatophagoides farinae drops in pre-school and school-age children with allergic rhinitis

BACKGROUND

The safety and efficacy of sublingual immunotherapy (SLIT) have been confirmed by many studies. However, in China, the research on efficacy and safety in young and older children with allergic rhinitis (AR) is still rare.

OBJECTIVE

The aim of this retrospective study is to evaluate the efficacy and safety of SLIT with Dermatophagoides farinae drops in pre-school and school-age children with AR.

METHODS

A total of 282 subjects aged 2-13 years with AR received a two-year course of sublingual immunotherapy along with pharmacotherapy. According to the age, patients were defined as the pre-school group (2-6 years old, n=116) and school-age group (7-13 years old, n=166). Total nasal rhinitis symptom scores (TNSS), visual analogue score (VAS) and total medication scores (TMS) were evaluated at four time points: baseline, after SLIT for half a year, one year and two years. The adverse events (AEs) were evaluated at each visit.

RESULTS

After two-year SLIT, the four rhinitis symptom scores, TNSS, VAS and TMS scores were significantly lower than baseline (all P<0.05). The comparison of efficacy between one and two-year duration showed no significant difference in global clinical outcomes (all P>0.05). In addition, there were no significant differences between the pre-school and school-age group in TNSS (all P>0.05), VAS (all P>0.05) and TMS scores (P>0.05) after SLIT for half a year, one year and two years. No severe systemic AEs were reported.

CONCLUSION

SLIT with D. farinae drops is clinically effective and safe in pre-school and school-age patients with house dust mites (HDMs)-induced AR.

Pediatric allergy and immunology in China

Over the past 30 years, China has enjoyed rapid economic development along with urbanization at a massive scale that the world has not experienced before. Such development has also been associated with a rapid rise in the prevalence of allergic disorders. Because of the large childhood population in the country, the burden of childhood allergic disorders has become one of the major challenges in the healthcare system. Among the Chinese centers participating in the International Study of Asthma and Allergies in Childhood, the data clearly showed a continuing rise in the prevalence of asthma, allergic rhinitis, and atopic eczema. However, the discipline of pediatric allergy in mainland China is still in its infancy due to the lack of formal training program and subspecialty certification. Clinicians and researchers are increasingly interested in providing better care for patients with allergies by establishing pediatric allergy centers in different regions of the country. Many of them have also participated in national or international collaborative projects hoping to answer the various research questions related to the discipline of pediatric allergy and immunology. It is our hope that the research findings from China will not only improve the quality of care of affected children within this country but also the millions of patients with allergies worldwide.

Migrant status and childhood hospitalizations for asthma and other wheezing disorders

BACKGROUND

In developed Western settings, asthma is more prevalent among second-generation compared to first-generation migrants. However, these studies are difficult to interpret as they include migrants of various ethnicities and countries of origin.

OBJECTIVE

We assessed the association of parental migrant status with wheezing disorders among children born in Hong Kong, a developed non-Western setting, where many children have migrant parents from mainland China of the same ethnicity.

METHODS

We used Cox regression to examine the adjusted associations of parental migrant status with time to first public hospital admission for asthma, bronchitis and bronchiolitis (International Classification of Diseases, Ninth Version Clinical Modification 466, 490 and 493) from 9 days to 12 years in a population-representative birth cohort of 8327 Chinese children in Hong Kong.

RESULTS

Having both parents as migrants was associated with higher risk of hospitalization for asthma and other wheezing disorders, compared to both parents being Hong Kong born (hazard ratio 1.30, 95% confidence interval 1.05-1.60 from 9 days to 6 years), adjusted for type of hospital at birth, parental history of allergies, mother's age at birth, father's age at birth and highest parental education.

CONCLUSIONS AND CLINICAL RELEVANCE

In the unique, non-Western context of Hong Kong, second-generation migrants had higher risk of hospitalization for childhood wheezing disorders compared to the native population, particularly before 6 years of age. Further study is required to clarify the underlying mechanisms involved.

Anti-Inflammatory Activities of Pentaherbs Formula, Berberine, Gallic Acid and Chlorogenic Acid in Atopic Dermatitis-Like Skin Inflammation

Atopic dermatitis (AD) is a common allergic skin disease, characterized by dryness, itchiness, thickening and inflammation of the skin. Infiltration of eosinophils into the dermal layer and presence of edema are typical characteristics in the skin biopsy of AD patients. Previous in vitro and clinical studies showed that the Pentaherbs formula (PHF) consisting of five traditional Chinese herbal medicines, Flos Lonicerae, Herba Menthae, Cortex Phellodendri, Cortex Moutan and Rhizoma Atractylodis at w/w ratio of 2:1:2:2:2 exhibited therapeutic potential in treating AD. In this study, an in vivo murine model with oxazolone (OXA)-mediated dermatitis was used to elucidate the efficacy of PHF. Active ingredients of PHF water extract were also identified and quantified, and their in vitro anti-inflammatory activities on pruritogenic cytokine IL-31- and alarmin IL-33-activated human eosinophils and dermal fibroblasts were evaluated. Ear swelling, epidermis thickening and eosinophils infiltration in epidermal and dermal layers, and the release of serum IL-12 of the murine OXA-mediated dermatitis were significantly reduced upon oral or topical treatment with PHF (all p < 0.05). Gallic acid, chlorogenic acid and berberine contents (w/w) in PHF were found to be 0.479%, 1.201% and 0.022%, respectively. Gallic acid and chlorogenic acid could suppress the release of pro-inflammatory cytokine IL-6 and chemokine CCL7 and CXCL8, respectively, in IL-31- and IL-33-treated eosinophils-dermal fibroblasts co-culture; while berberine could suppress the release of IL-6, CXCL8, CCL2 and CCL7 in the eosinophil culture and eosinophils-dermal fibroblasts co-culture (all p < 0.05). These findings suggest that PHF can ameliorate allergic inflammation and attenuate the activation of eosinophils.

Gestational Age, Birthweight for Gestational Age, and Childhood Hospitalisations for Asthma and Other Wheezing Disorders

BACKGROUND

Preterm birth, early term birth, and low birthweight are associated with childhood wheezing disorders in developed Western settings, but observed associations could be confounded by socio-economic position. This study aims to clarify such associations in a developed non-Western setting with a different confounding structure.

METHODS

Using Cox regression, we examined the adjusted associations of gestational age and birthweight for gestational age with time to first public hospital admission for asthma, bronchitis, and bronchiolitis (International Classification of Diseases, Ninth Version Clinical Modification 466, 490, and 493) from 9 days to 12 years in a population-representative birth cohort of 8327 Chinese children in Hong Kong, a developed setting with less clear social patterning of prematurity or birthweight. Analyses were adjusted for infant and parental characteristics and socio-economic position.

RESULTS

Children born late preterm (34 to <37 weeks) had higher risk of hospitalisation for asthma and other wheezing disorders [hazard ratio (HR) 1.99, 95% confidence interval (CI) 1.48, 2.67] than children born full term (39 to <41 weeks). Early term births (37 to <39 weeks) had HR 1.01 (95% CI 0.84, 1.22), late term births (41 to <42 weeks) had HR 0.77 (95% 0.59, 1.01), and post-term births (≥42 weeks) had HR 0.56 (95% CI 0.32, 0.98). Large for gestational age was associated with lower risk of hospitalisation (HR 0.76, 95% CI 0.57, 0.99).

CONCLUSION

The association of preterm birth with childhood wheezing could be biologically mediated. We cannot rule out an association for early term births.

Breastfeeding and childhood hospitalizations for asthma and other wheezing disorders

PURPOSE

Observationally in Western settings, breastfeeding is associated with less childhood wheezing disorders but may be confounded by socioeconomic position. We examined the association of breastfeeding with asthma and other wheezing disorders in a developed non-Western setting with unique social patterning of breastfeeding.

METHODS

Using Cox regression, we examined the adjusted associations of breastfeeding with public hospital admissions for asthma, bronchitis, and bronchiolitis (International Classification of Diseases, Ninth Version. Clinical Modification: 466, 490, and 493) from 3 months to 12 years in a population-representative birth cohort of 8327 Hong Kong Chinese children.

RESULTS

We did not find an association of exclusive breastfeeding for 3 months or more, compared with never breastfeeding, with hospitalization for asthma, bronchitis, and bronchiolitis to 12 years (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.63-1.25) nor for partial breastfeeding for any length of time or exclusive breastfeeding for less than 3 months (HR, 1.02; 95% CI, 0.86-1.21), adjusted for infant and parental characteristics and socioeconomic position. We also did not find an association of exclusive breastfeeding for 3 months or more with hospitalization for asthma only (International Classification of Diseases, Ninth Version. Clinical Modification: 493) (HR, 1.27; 95% CI, 0.82-1.98).

CONCLUSIONS

In a large population-representative Chinese birth cohort, we did not find an association of breastfeeding with childhood hospitalizations for asthma and other wheezing disorders.

Prevalence of allergic rhinitis among elementary and middle school students in Changsha city and its impact on quality of life

OBJECTIVES

To investigate the prevalence of allergic rhinitis among elementary and middle school students and examine its impact on their quality of life.

METHODS

Stratified sampling and cluster sampling surveys were performed among 10-17-year-old students in Changsha city from June 2011 to April 2012.

RESULTS

In the stratified sampling survey, the self-reported allergic rhinitis rate was 42.5 per cent. Further examination demonstrated that the average prevalence of allergic rhinitis was 19.4 per cent. The cluster sampling survey demonstrated that 214 of 814 students appeared to be atopic (26.3 per cent). The prevalence of allergic rhinitis and asthma was 17.2 and 2.1 per cent, respectively. In total, 71 atopic individuals (8.7 per cent) were without any symptoms of allergic disease. Further analysis showed that allergic rhinitis influenced the students' sleep, emotions and memory (p < 0.001).

CONCLUSION

The prevalence of allergic rhinitis was 15.8 -19.4 per cent, showing an increase with age. Allergic rhinitis affected students' sleep, emotions and memory.

The rural-urban enigma of allergy: what can we learn from studies around the world?

Childhood asthma and related allergic conditions have become the most common chronic disorders in the Western world. Many studies from around the world have demonstrated an increasing trend of asthma prevalence over the last few decades (Lancet, 368, 2004, 733). A few recent reports also suggested that childhood asthma prevalence may be showing a plateau or even a decline in few developed countries. Given the rapid changes in the prevalence over a short period of time, environmental factors are the more likely candidates explaining such trend. One of the most consistent epidemiological findings was that subjects living in the rural areas had lower prevalence of allergies when compared to those from urban areas (Clin Exp Allergy 30, 2000, 187; Pediatr Pulmonol 44, 2009, 793). Clear understanding of the mechanisms of how the environmental determinants in the rural environment may affect the early immune system resulting in lower risk of allergies and asthma will facilitate the development of future primary preventive strategies. In this study, we review recent data from around the world and explore the epidemiology and mechanistic studies that may explain the rural-urban difference of allergies.

A hospital-based survey on the prevalence of bronchial asthma in patients with allergic rhinitis in southern China

BACKGROUND

The prevalence of bronchial asthma (BA) and the underlying risk factors in patients with allergic rhinitis (AR) in China are largely unknown. Thus, this study is designed to assess the BA comorbidity in AR patients in two cities (Guangzhou and Zhuhai) of southern China and to determine the risk factors of BA in these AR patients.

METHODS

We performed a cross-sectional, hospital-based survey in two modernized cities in southern China. The BA prevalence was evaluated in 1931 AR patients. Participants were asked to complete a questionnaire containing specific items for AR and BA. A logistic regression analysis was used to assess the risk factors of BA comorbidity in AR patients.

RESULTS

The prevalence of concomitant BA in AR patients is 5.33% (103/1931). Most of the participants (98.4%) were sensitized to more than one allergen, and the most common sensitization was to house-dust mites. The strongest risk factor of BA determined by a multiple logistic regression analysis was a duration of AR of >5 years (adjusted odds ratio [OR], 8.67; 95% confidence interval [CI], 3.74-20.06), followed by smoking (adjusted OR, 7.21; 95% CI, 1.86-8.23) and self-medication with antibiotics (adjusted OR, 6.35; 95% CI, 3.43-11.78).

CONCLUSION

Our findings suggested the risk factors of concomitant BA in AR patients may be helpful to establish preventive strategies.

Asthma research in China: a five-year review

Asthma is one of the most common chronic diseases worldwide with increasing morbidity. China has the largest asthmatic population and is one of the countries with the highest asthma mortality. Fortunately, asthma research in China, both clinical and scientific, has developed markedly over the past few years. This has resulted in significant increases in our understanding of Chinese asthma prevalence, risk factors, control status, pathogenesis, and new prevention or treatment strategies. In this review, the major achievements of asthma research in China from 2008 to 2012 are summarized.

Efficacy and safety of sublingual immunotherapy in children aged 3-13 years with allergic rhinitis

BACKGROUND

Sublingual immunotherapy (SLIT) is recommended for allergic diseases. However, clinical studies containing evidence-based data of this treatment in young children, which is rarely reported in the literature, are needed. This study was designed to assess the efficacy and safety of SLIT in children, including very young children.

METHODS

Two hundred sixty-four children aged 3-13 years old (133 children, 3-5 years old) with Dermatophagoides farinae-induced allergic rhinitis with or without asthma treated by standard pharmacotherapy had randomly received either SLIT (SLIT group) or no SLIT (control group) for 12 months. Symptoms, medications, visual analog scale (VAS) and presence of adverse events (AEs) were assessed at monthly visits. Skin-prick test and Dermatophagoides farinae-specific IgE and IgG4 were measured before and after treatment.

RESULTS

Both treatments were effective in the global clinical scores during the first seven visits when compared with baseline (all, p < 0.01), and SLIT showed lower symptoms scores and VAS scores throughout this period (all, p < 0.01). These improvements continued until the later visits only in the SLIT group. Also, the asthma medication consumption was decreased by SLIT treatment only at the end of study (p < 0.01). The specific IgG4 was significantly increased after SLIT treatment when compared with the control group, but no significant change of specific IgE was observed in either groups. In the SLIT group, there was no significant difference between children less than or more than 5 years old in terms of clinical efficacy, onset of action, immunologic parameters, and safety. No severe systemic AEs were reported.

CONCLUSION

SLIT is effective and well-tolerated in children with allergic rhinitis 3-13 years old.

Vitamin D deficiency is associated with diagnosis and severity of childhood atopic dermatitis

BACKGROUND

Recent studies implicated the importance of vitamin D in innate immune defense and pathogenesis of allergic diseases. However, the impact of vitamin D deficiency on atopic dermatitis (AD) diagnosis and severity remains unclear. This case-control study investigated such relationship in Hong Kong Chinese children.

METHODS

Serum 25-hydroxyvitamin D [25(OH)D] levels of 498 AD children and 328 non-allergic controls were measured by immunoassay. Subjects were categorized into deficient (< 25 nm), insufficient (25-49.9 nm), and sufficient (≥ 50 nm) groups. Short-term and long-term AD severity was evaluated by physician-diagnosed SCORing Atopic Dermatitis (SCORAD) and Nottingham Eczema Severity Score (NESS), respectively. Atopy biomarkers were also measured for analysis.

RESULTS

The mean (s.d.) serum 25(OH)D levels in AD patients and controls were 28.9 (15.3) and 34.2 (14.5) nm, respectively (p < 0.001). More patients had serum 25(OH)D levels <25 nm than controls (47.8% vs. 26.6%). AD severity as indicated by both SCORAD and NESS showed inverse associations with serum 25(OH)D levels (respective p = 3.6 × 10(-4) and 0.004 when adjusted for age, sex, month of assessment, and immunoassay batch as covariates). Vitamin D-deficient patients (3.08 ± 0.76) had higher logarithm-transformed total IgE than those with insufficient (2.74 ± 0.69) and sufficient (2.72 ± 0.72) serum 25(OH)D levels (p < 0.001). The proportion of subjects with elevated IgE was higher in vitamin D-deficient (43.2%) than vitamin D-sufficient (20.0%) groups.

CONCLUSIONS

Vitamin D deficiency and insufficiency are prevalent in Hong Kong Chinese children. Vitamin D deficiency is associated with childhood AD and high total IgE. Serum 25(OH)D levels correlate inversely with both long- and short-term AD severity.

Prevalence, severity and risk factors of asthma, rhinitis and eczema in a large group of Chinese schoolchildren

BACKGROUND

There is a lack of information on the prevalence, severity and risk factors of asthma, rhinitis and eczema in Chinese children.

OBJECTIVE

To establish baseline data for a major longitudinal study of factors affecting asthma, rhinitis and eczema in a large group of children from the industrialized city of Shijiazhuang, China.

METHODS

We used the International Study of Asthma and Allergies in Childhood questionnaire and studied 10 338 children, ages 6-18, from Shijiazhuang.

RESULTS

The prevalence of childhood asthma, rhinitis and eczema is 1.2%, 13.5% and 11.8%, respectively. Boys had higher prevalence of these conditions than girls and younger children had higher prevalence of asthma and eczema but lower prevalence of rhinitis than older children. Breastfed children had lower prevalence of asthma and rhinitis, but not eczema, than non-breastfed children. Overweight children had higher prevalence of asthma and rhinitis than those who were not overweight. Children exposed to paternal smoking had higher prevalence of rhinitis and eczema than those not exposed; children exposed to pets had higher prevalence of asthma and rhinitis than those not exposed.

CONCLUSIONS

The prevalence of asthma in this study group is low, but the prevalence of rhinitis is high, and could be considered a major public health problem. The prevalence of asthma, rhinitis and eczema is generally higher in boys and younger children generally have higher prevalence of asthma and eczema but lower prevalence of rhinitis. Exposure to pets is a risk factor for rhinitis, being overweight is a risk factor for asthma and rhinitis, and exposure to parental smoking is a risk factor for asthma, rhinitis and eczema in these children.

Prevalence of allergic rhinitis in china

Allergic rhinitis (AR) is a serious systemic allergic disease, which together with comorbid asthma causes major illness and disability worldwide. Recent epidemiological studies have revealed wide variations in the increasing prevalence of AR and allergies globally, including in China. Despite a markedly higher population than western countries, and a landmass close to Europe in area, little epidemiological data is available on AR in China. Thus, the present study reviewed the prevalence, comorbid allergic diseases, trends and pattern of sensitizing allergens in adults and children suffering from AR in China. Available data indicated that despite variations in the prevalence of AR in different regions of the country, the prevalence of AR has increased in both adults and children over the last 2 decades. Similarly, there has been an increase in a "western"-type lifestyle, industrialization and air pollution over this period, which may have contributed to the increased prevalence of AR observed in China.

Use of acid-suppressive drugs in pregnancy and the risk of childhood asthma: bidirectional crossover study using the general practice research database

BACKGROUND

Recent studies have reported an association between maternal use of gastric acid-suppressive drugs during pregnancy and asthma in the offspring, but the association could have been confounded by unmeasured risk factors.

OBJECTIVE

We assessed the association between the use of acid-suppressive drugs during pregnancy and the risk of developing childhood asthma using a bidirectional crossover design.

METHODS

Mother-infant matched sets in the UK General Practitioners Research Database were used to identify children with a drug-treated asthma diagnosis during the years 2006-2010 who were matched to a sibling without asthma as controls. Primary exposure was use of any anti-suppressive drug during pregnancy, and subgroup analyses were conducted according to drug class (e.g. proton pump inhibitors or histamine 2 receptor antagonists) and trimester. Conditional logistic regression was used to estimate odds ratios (OR) with their corresponding 95 % confidence intervals (CIs).

RESULTS

A total of 1,874 children with asthma and 1,874 control siblings were included in the analysis. The exposure rate among case and control pregnancies was 22 and 20 %, respectively. After adjustments for gender, birth order, mother's age and general practice visits, the exposure to any gastric-acid suppressive drug during pregnancy slightly increased the risk for developing asthma (OR 1.23, 95 % CI 1.01-1.51; p = 0.042). A trend towards increased risks was observed for those who used proton pump inhibitors and/or histamine 2 receptor antagonists (adjusted OR 1.72, 95 % CI 1.00-2.98; p = 0.048).

CONCLUSIONS

These findings lend support to the emerging evidence that exposure to acid-suppressive drugs during pregnancy is associated with childhood asthma. More basic research is now warranted to investigate the mechanisms.

Cross-sectional epidemiological survey of asthma in Jinan, China

BACKGROUND AND OBJECTIVE

The prevalence and control of asthma in all ages are seldom known in Jinan, China. This study aims to determine the prevalence, related factors and control of asthma in populations of all ages in Jinan, China.

METHODS

A cross-sectional epidemiological questionnaire survey was performed with all members from approximately 4500 randomly selected families from 60 communities in the urban area and in 40 villages in the rural area. The completed questionnaires were focused on asthma, asthma-like respiratory symptoms and asthma control.

RESULTS

A total of 13,645 individuals were interviewed in the survey, and the number of effective questionnaires reached 13,419. The asthma prevalence of all ages in Jinan was 1.1%. Atopy, asthma family history, household size and age were independent factors related to asthma. The control of asthma in Jinan was suboptimal in a high proportion of patients and even worse in the rural area.

CONCLUSIONS

The asthma prevalence for all ages in Jinan was relatively low compared with that in western countries; however, local asthma control fell markedly short from the goals of the Global Initiative for Asthma (GINA) criteria for asthma management, which may be attributed to the poor adherence to GINA guidelines, especially the underuse of preventative medication of inhaled corticosteroids.

Changing prevalence of allergic diseases in the Asia-pacific region

Asia-Pacific is one of the most densely populated regions of the world and is experiencing rapid economic changes and urbanization. Environmental pollution is a significant problem associated with the rapid modernization of many cities in South Asia. It is not surprising that the prevalences of asthma and allergies are increasing rapidly, although the underlying reasons remain largely unknown. Many studies from this region have documented the changing prevalence of allergic diseases in various parts of the world. However, the methodologies used were neither standardized nor validated, making the results difficult to evaluate. The International Study of Asthma and Allergies in Childhood (ISAAC) has provided a global epidemiology map of asthma and allergic diseases, as well as the trend of changes in the prevalence of these diseases. Allergic sensitization is extremely common in many Asian communities. However, the prevalence of allergic diseases remains relatively rare. The rapid urbanization in the region, which increases environmental pollution and can affect the rural environment, will likely increase the prevalence of asthma and allergies in Asia.

Association between obesity and atopic disorders in Chinese adults: an individually matched case-control study

BACKGROUND

Obesity is regarded as a potential risk factor for atopy. The aim of this study was to assess the associations of obesity with atopic dermatitis, rhinitis, asthma and food allergy in Chinese adults.

METHODS

Two hundred and sixty six (266) atopic cases in Harbin, China, were identified according to the current Chinese guidelines for the diagnosis of atopic diseases. All cases had a previous diagnosis of atopic disorders (atopic dermatitis, rhinitis, asthma or food allergy) and were positive in one or more allergen specific IgE tests to 16 common allergens in the region. Each case was individually matched to two healthy controls based on their age, sex, and residential regions. All 532 healthy controls were negative in allergen specific IgE tests. The associations of obesity with four atopic disorders were assessed using a conditional logistic regression method.

RESULTS

Obesity was significantly associated with the presence of atopic diseases (OR = 3.2, 95% CI: 1.8, 5.7). Males and females had a similar association (OR = 3.1 for males and 3.2 for females). The associations of obesity with atopic dermatitis (OR = 2.7, 95% CI: 1.2, 6.3) and atopic rhinitis (OR = 3.1, 95% CI: 1.1, 8.7) were statistically significant. Although obesity was positively associated with atopic asthma, this association was not statistically significant (OR = 3.4, 95% CI: 0.6, 19.9). The association between obesity and food allergy was weak and not significant (OR = 1.1, 95% CI: 0.4, 3.7).

CONCLUSIONS

Obesity is positively associated with the presence of atopic diseases in Chinese adults. Specifically, obesity is significantly associated with atopic dermatitis and rhinitis. Our findings warrant further investigation on the causal nature between obesity and atopic diseases and the effect of weight reduction on preventing atopic diseases.

The prevalence of childhood asthma in China: a systematic review

BACKGROUND

It is well known that the prevalence of asthma has been reported to increase in many places around the world during the last decades. Therefore, the aim of this study was to identify and review studies of asthma prevalence among children in China and address time trends and regional variation in asthma.

METHODS

A systematic literature search was performed using PubMed and China National Knowledge Infrastructure (CNKI) databases. Selected articles had to describe an original study that showed the prevalence of asthma among children aged 0-14 years.

RESULTS

A total of 74 articles met the inclusion criteria. The lifetime prevalence of asthma varied between 1.1% in Lhasa (Tibet) and 11.0% in Hong Kong in studies following the International Study of Asthma and Allergies in Childhood (ISAAC) protocol. The prevalence was 3% or lower in most articles following Chinese diagnostic criteria. One article reported the results from two national surveys and showed that the current average prevalence of asthma for the total study population had increased from 1990 to 2000 (0.9% to 1.5%). The lowest current prevalence was found in Lhasa (0.1% in 1990, 0.5% in 2000).

CONCLUSIONS

The prevalence of childhood asthma was generally low, both in studies following the ISAAC and Chinese diagnostic criteria. Assessment of time trends and regional variations in asthma prevalence was difficult due to insufficient data, variation in diagnostic criteria, difference in data collection methods, and uncertainty in prevalence measures. However, the findings from one large study of children from 27 different cities support an increase in current prevalence of childhood asthma from 1990 to 2000. The lowest current prevalence of childhood asthma was found in Tibet.

Comparison of total suspended particulate concentration-response relationships for respiratory symptoms between Chinese children with a different susceptibility status

Few studies have explored concentration-response (C-R) relationships between levels of particulate matter (PM) and respiratory morbidity in terms of the susceptibility of children to respiratory diseases. We sought to determine whether the shapes of C-R curves for comparing total suspended particle (TSP) concentration versus the adjusted prevalence of bronchitis (persistent cough or phlegm) and asthma (current wheeze or asthma) symptoms between children with a different susceptibility status. We used the restricted cubic spline (RCS) function to characterize the C-R relationships between TSP and the adjusted prevalence rates of four respiratory symptoms, after controlling for possible confounding by SO(2) and NO(2) levels, in 11,860 children selected from 18 districts of six cities in Liaoning province. Susceptible children exhibited a 2- to 3-fold elevation in the prevalence of all four respiratory symptoms across the entire TSP range (188-689μg/m(3)). Significant differences in the shapes of C-R curves were evident in children with symptoms of bronchitis (ballistic "S"-shaped curves) and asthma (flattened "U"-shaped curves), as well as between the low and high TSP ranges of such curves, when children were grouped by susceptibility status. A significant linear association between TSP levels and current asthma prevalence was found only among susceptible children exposed to high levels of TSP. The shapes and properties of the TSP-morbidity C-R curves differed significantly by type of respiratory symptom, susceptibility status, and TSP range. More work is required to characterize CR relationships in terms of susceptibility status in countries with different PM levels.

Importance of allergy in asthma: an epidemiologic perspective

There has been a global epidemic of asthma during the past half-century. More recently, the prevalence has leveled off or declined in many Western countries, whereas the prevalence in less affluent nations is still increasing. The reasons for this and the different geographical patterns of asthma prevalence remain unclear. This paper provides an epidemiologic perspective on whether allergen exposure and allergies can explain these trends. In particular, the paper discusses 1) geographical and temporal trends in asthma and the role of allergens and allergy, 2) the importance of nonallergic mechanisms, 3) nonallergenic exposures that may modify the risk of allergies and asthma, and 4) new and emerging risk and protective factors. Although allergy and asthma are closely related, allergen exposure and allergy alone cannot explain current time trends and geographical patterns of asthma. Population-based studies focusing on recently identified risk and protective factors may provide further insight.

Gestational medication use, birth conditions, and early postnatal exposures for childhood asthma

Our aim is to explore (1) whether gestational medication use, mode of delivery, and early postnatal exposure correlate with childhood asthma, (2) the dose responsiveness of such exposure, and (3) their links to early- and late-onset asthma. We conducted a matched case-control study based on the Taiwan Children Health Study, which was a nationwide survey that recruited 12-to-14-year-old school children in 14 communities. 579 mothers of the participants were interviewed by telephone. Exclusive breastfeeding protected children from asthma. Notably, childhood asthma was significantly associated with maternal medication use during pregnancy, vacuum use during vaginal delivery, recurrent respiratory tract infections, hospitalization, main caregiver cared for other children, and early daycare attendance. Exposure to these factors led to dose responsiveness in relationships to asthma. Most of the exposures revealed a greater impact on early-onset asthma, except for vacuum use and daycare attendance.

Life style and home environment are associated with racial disparities of asthma and allergy in Northeast Texas children

A high prevalence and racial disparities in asthma and allergy have been observed in American children. This study aimed to identify risk factors for asthma and allergy among children, and their contribution to racial disparities in allergy prevalence. A population-based cross-sectional study was carried out among children aged 1-8 years in Northeast Texas 2008-2009. The health conditions, life style and home environment of 3766 children were surveyed by parental questionnaires through e.g. daycares, elementary school, and medical clinics. Among participants who indicated their ethnicity, 255 were Mexican-Americans, 178 Afro-Americans and 969 Caucasians. Afro-American children had a significantly higher prevalence of asthma and eczema. Caucasian had the highest prevalence of rhinitis. Compared to Mexican-American children, Afro-American and Caucasian children were breast fed shorter time, more often went to day care center, had pets and environmental tobacco smoke exposure at home more often. For all children, being at a day care center, being exposed to dampness and environmental tobacco smoke at home were strong risk factors for asthma and allergy. Central air conditioning system was associated with an increased prevalence of wheeze among Mexican-American children, while pets were associated with an increased risk of rhinitis among Afro-American and Caucasian children. Caucasian children were generally not healthier than relatively poor Mexican-American children. Differences in the prevalence of asthma and allergy between races cannot be explained by socioeconomic status only. Life style and home environmental exposures are important risk factors for asthma and allergy in Northeast Texas children.

Lessons for primary prevention of asthma: foreign-born children have less association of SES and pests with asthma diagnosis

There are no proven interventions for primary prevention of asthma. As asthma prevalence varies globally, comparing asthma in native and foreign-born children might provide insights. We pooled data from five cross sectional asthma surveys (N = 962). Place of birth was associated with asthma (OR = 3.4, P < 0.001). In children not born in the US, lower socio-economic status had no significant effect on asthma (OR = 0.71, P = 0.53), while for children born in the US, the effect was significant (OR = 2.1, P = 0.001). The odds ratio for exposure to household pests was significant (OR = 1.6, P < 0.008) for children born in the US but was non-significant for children born outside the US (OR = 0.29, P = 0.11). Our findings are consistent with foreign-born children experiencing protective factors or US born children experiencing detrimental environmental exposures.

Prevalence of non-communicable diseases in Brazilian children: follow-up at school age of two Brazilian birth cohorts of the 1990's

Background

Few cohort studies have been conducted in low and middle-income countries to investigate non-communicable diseases among school-aged children. This article aims to describe the methodology of two birth cohorts, started in 1994 in Ribeirão Preto (RP), a more developed city, and in 1997/98 in São Luís (SL), a less developed town.

Methods

Prevalences of some non-communicable diseases during the first follow-up of these cohorts were estimated and compared. Data on singleton live births were obtained at birth (2858 in RP and 2443 in SL). The follow-up at school age was conducted in RP in 2004/05, when the children were 9-11 years old and in SL in 2005/06, when the children were 7-9 years old. Follow-up rates were 68.7% in RP (790 included) and 72.7% in SL (673 participants). The groups of low (<2500 g) and high (≥ 4250 g) birthweight were oversampled and estimates were corrected by weighting.

Results

In the more developed city there was a higher percentage of non-nutritive sucking habits (69.1% vs 47.9%), lifetime bottle use (89.6% vs 68.3%), higher prevalence of primary headache in the last 15 days (27.9% vs 13.0%), higher positive skin tests for allergens (44.3% vs 25.3%) and higher prevalence of overweight (18.2% vs 3.6%), obesity (9.5% vs 1.8%) and hypertension (10.9% vs 4.6%). In the less developed city there was a larger percentage of children with below average cognitive function (28.9% vs 12.2%), mental health problems (47.4% vs 38.4%), depression (21.6% vs 6.0%) and underweight (5.8% vs 3.6%). There was no difference in the prevalence of bruxism, recurrent abdominal pain, asthma and bronchial hyperresponsiveness between cities.

Conclusions

Some non-communicable diseases were highly prevalent, especially in the more developed city. Some high rates suggest that the burden of non-communicable diseases will be high in the future, especially mental health problems.

Self-reported prevalence of childhood allergic diseases in three cities of China: a multicenter study

BACKGROUND

Several studies conducted during the 1990s indicated that childhood allergic diseases were increasing worldwide, but more recent investigations in some Western countries have suggested that the trend is stabilizing or may even be reversing. However, few data are available on the current status of allergic disease prevalence in Chinese children. The aim of the present study was to investigate the prevalence rates of asthma, allergic rhinitis, and eczema in children of three major cities of China, to determine the status of allergic diseases among Chinese children generally, and to evaluate the prevalence of allergic diseases in children of different ages.

METHODS

We conducted a cross-sectional survey between October 2008 and May 2009 in three major cities of China (Beijing, Chongqing, and Guangzhou) to evaluate the prevalence rates of childhood allergic diseases including asthma, allergic rhinitis, and eczema, using a questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC) group. A total of 24,290 children aged 0-14 years were interviewed, using a multi-stage sampling method. To acquire data on children aged 3-14 years, we visited schools and kindergartens. To access children too young to attend school or kindergarten, we extended our survey to community health service centers. Each questionnaire was completed by a parent or guardian of a child after an informed consent form was signed.

RESULTS

Of the 24,290 children in our study, 12,908 (53.14%) were males and 11,382 (46.86%) females; 10,372 (42.70%) were from Beijing, 9,846 (40.53%) from Chongqing, and 4,072 (16.77%) from Guangzhou. Our survey indicated that in Beijing, Chongqing, and Guangzhou, the prevalence rates of asthma were 3.15%, 7.45%, and 2.09%, respectively; the rates of allergic rhinitis were 14.46%, 20.42%, and 7.83%; and the rates of eczema were 20.64%, 10.02%, and 7.22%. The prevalence of allergic diseases varied with age. Asthma was relatively less common both in children aged under 2 years, and in those aged 9 years or more, in each of the three cities. The prevalence of allergic rhinitis was also lower in children younger than 2 years. The prevalence of eczema fell with age.

CONCLUSIONS

A marked increase in the prevalence rates of allergic diseases in China (compared with earlier data) was evident. Further studies exploring the precise causes of this increase are warranted.

Serum levels of heavy metals in childhood eczema and skin diseases: friends or foes

The incidence of eczema has been increasing in developed countries. Environmental and hygiene factors have been incriminated. Although air and food pollution with heavy metals have been considered as possible culprits, these factors have never been investigated in Hong Kong. To evaluate if quality of life and eczema severity are associated with abnormal serum levels of six common heavy metals, namely, cadmium, lead, mercury, selenium, copper and zinc. Serum or whole blood was taken for measurement of six heavy metals from patients referred to the pediatric dermatology clinic. Eczema severity (SCORAD and NESS) and quality of life (CDLQI) were recorded. A total of 110 patients with eczema and 41 patients with miscellaneous skin conditions were recruited. Serum levels of the six heavy metals were generally within the upper limits of local reference ranges. Zinc levels were below the lower reference limit of 9.4 mum in 66 patients with eczema (60%) and 22 non-eczema patients (53%). Forty-four patients with eczema (40%) and 24 (58%) in non-eczema group had low copper levels. In eczema patients, lead levels were generally within normal limits but their levels were positively correlated with poor quality of life (CDLQI: r = 0.22 and p < 0.05), disease severity (objective SCORAD: r = 0.33 and p < 0.005; NESS: 0.20, p < 0.05), eosinophil count and log-transformed IgE. Copper/zinc ratio also correlated with NESS and CDLQI and was generally higher than non-eczema skin diseases. Our findings help reassure parents that levels of heavy metals generally do not exceed the local reference ranges for toxicity. However, lead levels have significant correlations with disease severity, quality of life and atopy. Low zinc and copper levels are commonly found in pediatric skin diseases and their significance needs to be determined.

Mechanism of asthmatic exacerbation by ambient air pollution particles

In the previous two to three decades, the prevalence of asthma has risen in numerous countries of the world. Correlating with this elevated prevalence of asthma, societies have observed increased air pollution from specific sources. Studies have implicated certain pollutants in asthmatic exacerbation. Particulate matter (PM) is the pollutant most frequently identified with worsening of this airway disease. PM is a temporally and spatially shifting suspension of solids and liquids originating from both natural and anthropogenic sources. Exposures to elevated levels of PM have been associated with asthmatic exacerbations by employing a diverse array of end points, including respiratory symptoms, use of medication, medical visits, emergency room visits, hospital admissions and pulmonary function decrements. Pertinent to worsening of asthma by ambient air PM, there are other particle-associated exposures that similarly precipitate asthmatic exacerbations. These include traffic-associated pollutants, diesel exhaust, emissions from gas and wood stoves, burning of biomass and environmental tobacco smoke. It is widely accepted that the biological effects exerted by all particle exposures result from oxidative stress. This stimulates cell signaling, transcription factor activation and mediator release in the respiratory tract, culminating in inflammation. Other postulated mechanisms for asthmatic exacerbation following PM exposure include an impact on the incidence of infections and adjuvant effects.

Allergies in Asia: differences in prevalence and management compared with western populations

There is wide variability in the epidemiology and management of childhood asthma and related atopic diseases globally. Urbanized, affluent Western countries tend to have a higher prevalence of these diseases compared with Asian nations. However, recent studies have shown that the prevalence in Asia is increasing, although the rate of increase has slowed in the more developed Asian cities. Some possible causes for these differences are socioeconomic status, degree of urbanization, rates of infection, healthcare practices and genetic factors. Importantly, there are significant differences in the way asthma and allergic diseases are managed within Asia. This is of great concern because of the health implications, as these diseases are some of the most common chronic conditions that affect both adults and children. This review compares the differences in prevalence and management between Asia and the West, and discusses some of the possible reasons behind these variations.

Multiplex molecular detection of respiratory pathogens in children with asthma exacerbation

BACKGROUND

Up to 80% of asthma exacerbations in white children are associated with viral upper respiratory infections. The relative importance of different respiratory pathogens and relevant microbiological data in Asian children are unclear. This study elucidated the epidemiology of respiratory infections in Hong Kong children with asthma exacerbation.

METHODS

A total of 209 children aged 3-18 years with asthma exacerbations and 77 controls with stable asthma were recruited. The severity of asthma exacerbations was assessed according to Global Initiative for Asthma guideline, and subjects aged 6 years or older performed exhaled nitric oxide and spirometric measurements. Nested multiplex polymerase chain reaction was used to detect 20 different respiratory pathogens.

RESULTS

Respiratory pathogens were detected in 105 (51.0%) subjects. The presence of any respiratory pathogen was associated with asthma exacerbation (odds ratio [OR], 2.77; 95% CI, 1.51-5.11; P < .001). Specifically, human rhinovirus (HRV) infection was more common among children with asthma exacerbation (OR, 2.38; 95% CI, 1.09-5.32; P = .018). All other pathogens or coinfections were not associated with asthmatic attacks. None of these respiratory infections was associated with the severity of asthma exacerbation (P > .15 for all). During peak HRV season in the winter of 2007 to 2008, this virus was detected in 46.4% of children with asthma exacerbations.

CONCLUSIONS

Respiratory viral infections are commonly found in children with asthma exacerbation, with HRV being the most important pathogen in our patients. Respiratory viral infection is a triggering factor for asthma exacerbation but does not correlate with its severity.

Very low prevalence of asthma and allergies in schoolchildren from rural Beijing, China

BACKGROUND

The prevalence of asthma is relatively low in the Chinese population. There is consistent evidence that growing up on a farm is associated with protection against the subsequent development of asthma.

OBJECTIVE

To compare the prevalence of asthma in schoolchildren from urban and rural China and to assess the possible protection associated with agricultural and livestock farming.

METHODS

Random samples of schoolchildren aged 13-14 years from urban Beijing and rural area around Beijing were studied using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase III protocol. Subjects were studied by questionnaires (n = 7,077) and skin-prick tests (n = 2,126).

RESULTS

The prevalence rates of wheeze in the past year and physicians' diagnosis of asthma were 1.0% and 1.1% in the rural area, and these were significantly lower than 7.2% and 6.3% found in the urban children (P < 0.0001). For the video questionnaire, only 0.3% of rural children reported wheeze in the past year compared with 3.1% in urban children (P < 0.0001). Atopy was 3.22 times higher in urban children compared with rural children (P < 0.0001). For rural schoolchildren, 1,453 (41%) have always been living on agricultural farms since birth and the prevalence rates of their asthma symptoms and atopic sensitization were not significantly different from those who have exposed to livestock farming.

CONCLUSION

Using the same validated ISAAC questionnaire and objective skin-prick tests, the prevalence rates of asthma and atopic sensitization in rural Chinese children were significantly lower than urban children. Exposure to agricultural farming conferred the same protection as livestock farming.

What have we learnt from ISAAC phase III in the Asia-Pacific rim?

PURPOSE OF REVIEW

International Study of Asthma and Allergies in Childhood (ISAAC) phase III had provided a worldwide map of epidemiology of asthma and allergic diseases, as well as the changes in prevalence rate of these diseases when compared to data obtained in phase I. The wide variations of environmental factors and ethnic background in Asia provide excellent opportunities for research into the environmental and genetic determinants of asthma and allergies. This review summarizes important lessons learnt from ISAAC phase III results from Asia on asthma and allergy.

RECENT FINDINGS

ISAAC phase III provided epidemiological evidence of the wide variation and increasing prevalence of asthma and allergy in many Asian countries. When compared to other regions of the world, Asia has a relatively lower prevalence of asthma and allergic diseases. Comparative studies of populations of the same ethnic group living in different environments reveal striking disparity in prevalence of asthma and allergic diseases. The established risk factors could not explain the secular trend and variations of asthma prevalence in different Asian countries. Further research is needed in this rapidly changing region of Asia in order to identify the protective or risk factors associated with the development of asthma.

SUMMARY

ISAAC phase III provides standardized data on the prevalence and burden of asthma and allergy in the Asia-Pacific region. Further research is needed to reveal the underlying factors responsible for the wide variations in disease manifestations in the region.

Dental arch widths of Southern Chinese

OBJECTIVE

To investigate the dental arch width of the Southern Chinese across buccal cusps, central fossae, or lingual cusps and compare these values with study findings in different populations and using different definitions.

MATERIALS AND METHODS

The dental arch dimensions of study casts of an unselected sample from a 12-year-old Hong Kong Oral Health Survey of 12-year-old children (n = 358; 210 boys and 148 girls) were measured.

RESULTS

When compared with Caucasians, the Southern Chinese were characterized by a wider dental arch width. However, variations were great. All maxillary and mandibular male arch widths were significantly larger than female arch widths, except at the incisor regions.

CONCLUSION

This study yielded a database about dental arch widths by which different studies on these widths can be compared.

The Asian side of asthma and allergy

PURPOSE OF REVIEW

There is wide variation in the global epidemiology of allergic diseases, and the prevalence rates of asthma and allergy differ significantly among different Asian populations. The diversity of environment and ethnic background in Asia provide excellent opportunities for research into the environmental and genetic determinants of asthma and allergies. This review summarizes important lessons learnt from research findings from Asia on asthma and allergy.

RECENT FINDINGS

Recent epidemiologic studies revealed wide variation and increasing prevalence of asthma and allergy in many Asian countries. Comparative studies of population of the same ethnic background living in different environments revealed important environmental risk factors for asthma. Ambient air pollution plays an important role in the morbidity of patients with asthma but does not seem to affect the prevalence of asthma. There were many genetic association studies for allergic diseases from Asia. These studies identified novel gene targets, such as CD40, DCNP1 and PTGS2, for asthma and allergen sensitization whereas many others replicated the genetic associations on known candidate genes for asthma and atopic dermatitis.

SUMMARY

Epidemiologic and genetic researches in Asia advance our knowledge on the disease prevalence, healthcare burden and pathogenesis of asthma and allergy.