Time trends of the prevalence of asthma, rhinitis and eczema in Thai children-ISAAC (International Study of Asthma and Allergies in Childhood) Phase Three

Trends of aeroallergen sensitization among children with respiratory allergy in Southern Thailand

Background

Respiratory allergy significantly impacts children's health and quality of life, with inhaled allergens serving as prevalent triggers for respiratory symptoms. Aeroallergen sensitization, confirmed through the skin prick test (SPT), naturally evolves over time and is influenced by environmental factors specific to each region.

Objective

This study aimed to review the updated 6-year trend of aeroallergen sensitization among children with asthma and allergic rhinitis in Southern Thailand.

Methods

This retrospective study involved a review of patients aged ≤15 years diagnosed with asthma and/or allergic rhinitis, who underwent the SPT using 12 standardized aeroallergens.

Results

The medical records of 1,393 children were reviewed, with 63% being male, and the mean age was 7.4 ± 3.3 years. Among them, 55.5% presented with allergic rhinitis alone, followed by 31.6% with asthma and allergic rhinitis, and 12.9% with asthma alone. Over the 6-year period, house dust mites emerged as the most common sensitized allergen, followed closely by cockroaches, maintaining a consistent trend of sensitization. Dermatophagoides pteronyssinus ranked as the predominant sensitized allergen across all diagnoses (63% in asthma with allergic rhinitis, 52.7% in allergic rhinitis, and 43.5% in asthma). Children diagnosed with both asthma and allergic rhinitis exhibited a higher prevalence of sensitization to house dust mites, cockroaches, Johnson grass, acacia, Candida albicans, and cat pelts compared with those with asthma or allergic rhinitis alone. Additionally, the prevalence of house dust mite and cockroach sensitization was notably higher in older children (≥5 years old) with respiratory allergies.

Conclusion

House dust mites and cockroaches emerge as the 2 most prevalent sensitized aeroallergens among children diagnosed with asthma and/or allergic rhinitis, exhibiting consistent trends of sensitization over the past 6 years. The persistence of these causative allergens underscores the importance of meticulous environmental control measures for children affected by respiratory allergies.

[Epidemiological profile of allergic respiratory disease in Mexican children]

OBJECTIVE

Report the prevalence and severity of the most common allergic diseases in children living in Monterrey, México.

METHODS

Cross-sectional multi-center survey on the most common allergic diseases, completed by parents of 6-7-year-old children and by 13-14- year-old adolescents in the Monterrey metropolitan area, between January 2018 and December 2019.

RESULTS

A total of 3,044 questionnaires were eligible for the analysis. Among children between 6-7 years old, 30.2% (n = 143/473) presented wheezing at any time in their life; with a higher prevalence in the male population. In the adolescent group, 26.4% reported having experienced wheezing at some point in their life, with a slight predominance in the female group (54.9%).

CONCLUSIONS

Knowing the prevalence of allergic diseases in our population gives us tools to generate strategies that allow us to provide the best quality healthcare to our patients.

Unveiling the potential: Enhancing caregiver knowledge through video education to address topical corticosteroid concerns in children with eczematous dermatitis

BACKGROUND

Concerns about the use of topical corticosteroids (TCS) in pediatric eczematous dermatitis management often hinder effective treatment. Limited data exist regarding the prevalence of these concerns and the effectiveness of interventions. This study aimed to assess the prevalence of TCS concerns among caregivers and determine the effectiveness of video education in mitigating these concerns.

METHODS

A single-center prospective study was conducted from 2022 to 2023, involving caregivers of children under 18 years with eczematous dermatitis. Baseline and post-intervention questionnaires were administered after a 4-week period. Caregivers received video education on TCS use, and the TOPICOP score was evaluated before and after viewing the video.

RESULTS

The study included 150 caregivers, 85.3% female and 74% had a child with atopic dermatitis. The prevalence of TCS concerns among Thai caregivers was 62%. Following video education, the prevalence of TCS concerns significantly decreased to 10.7%. Mean belief score decreased from 43.81 ± 13.45 to 31.85 ± 16.56, mean worry score decreased from 56.22 ± 18.27 to 40.41 ± 18.55 and mean total TOPICOP score decreased from 50.02 ± 12.65 to 36.13 ± 13.52 (p-value <.001). The intervention also resulted in reduced disease exacerbations, duration of the rash, and duration of TCS use. The optimal TOPICOP cut-off score to predict TCS concerns was identified as 43.06.

CONCLUSION

Video education effectively alleviated TCS concerns among caregivers, addressing beliefs, worries, disease exacerbations, and side effects. Integration of this intervention into the management of pediatric eczematous dermatitis can yield optimal outcomes.

Allergic rhinitis and other comorbidities associated with asthma control in Thailand

Background

Asthma and allergic rhinitis (AR) can coexist and cause disabilities. This study aimed to assess the association between AR, asthma control, asthma-related quality of life, and other comorbidities.

Methods

A cross-sectional study was conducted in adults with asthma in six hospitals in Thailand. The outcomes were association of asthma control assessed by the asthma control test (ACT), AR, and asthma comorbidities. Not-well-controlled asthma was defined as ACT scores ≤22. The severity of AR was determined by visual analog scale (VAS). Severe AR was defined as VAS ≥5. Asthma-related quality of life (AQLQ), comorbidities, and total IgE were recorded.

Results

A total of 682 asthmatic patients were included. Median (IQR) age was 58.0 (47.0-64.0) years. 69.9% were female. Not-well-controlled asthma was present in 44.7%. The prevalence of AR was 86.1%. Moderate/severe persistent AR was diagnosed in 21.7% and severe AR was diagnosed in 30.2% of the patients. Inhaled corticosteroid-containing regimens were prescribed in 97.7% of patients. Intranasal corticosteroid and antihistamine were prescribed in 65.7 and 31.7%, respectively. Patients with not-well-controlled asthma had higher body mass index, VAS scores, proportions of pollution exposure, aeroallergen sensitization, severe AR, nasal polyp, urticaria, food allergy, gastroesophageal reflux disease, depression and anxiety, peptic ulcer, and asthma exacerbations, but younger age, lower AQLQ scores, and lower FEV1. Correlation was found between AR severity and ACT (r = -0.461, p < 0.001), AQLQ (r = -0.512, p < 0.001), and total IgE (r = 0.246, p < 0.023). Multiple regression analysis revealed that ACT, AQLQ, and percentage of FEV1/FVC were significantly associated with severe AR.

Conclusion

Allergic rhinitis is prevalent in Thai asthmatic patients. AR severity is associated with asthma control, quality of life, and pulmonary function. Comprehensive care is essential for patients with uncontrolled asthma, particularly when coexisting with conditions.

The role of the environment in shaping the trends of childhood asthma - An Asian perspective

Asthma has now become one of the most common atopic disorders not only in developed countries but also in many developing countries. The etiology is likely due to a complex interaction between genetic and environmental factors. In many Asian countries, the prevalence of asthma has also been documented by validated instruments to be increasing rapidly over the past two decades. However, studies in rural areas in Asia with a traditional farming environment revealed markedly lower asthma prevalence when compared with residents in nearby cities despite having similar genetic background. Among the environmental factors implicated in the pathogenesis of asthma, air pollution, dietary patterns, viral infections, and early microbial exposure have been studied extensively around the world. Asia provides many opportunities to study these potential factors as there are many ethnic groups living in distinctly different environments. The understanding of the roles of these factors in affecting the early immune system and subsequent development of asthma will enable us to develop potential primary preventive strategies against a disease which affects millions worldwide.

Comparison of exhaled nitric oxide levels in pediatric patients with allergic rhinitis

OBJECTIVE

To determine whether the measurement of exhaled nitric oxide (eNO) can help distinguish children with allergic rhinitis (AR) from healthy controls and whether eNO in children with AR correlates with disease severity.

METHODS

From August 2015 to 2016, children aged 5-15 years of age grouped into those with allergic rhinitis (n = 40) and those classified as healthy control subjects (n = 40) had exhaled nitric oxide (eNO) levels measured. The eNO level was additionally compared to the patient's clinical disease severity according to the ARIA (Allergic Rhinitis and its Impact on Asthma) classification.

RESULTS

Mean eNO in children with AR (12.64 ± 14.67 ppb) was significantly higher than that in the healthy control group (7.00 ± 6.33 ppb) (p-value = 0.046). In the persistent AR group (17.11 ± 18.40 ppb), eNO level was significantly higher than individuals in the intermittent AR group (8.59 ± 8.88 ppb, p-value = 0.024) and the healthy control group (7.00 ± 6.33 ppb, p-value = 0.008). Among children with AR, eNo was not significantly different with relationship to gender, age, weight and passive smoking exposure.

CONCLUSIONS

Exhaled nitric oxide may be elevated in children with AR that do not have concomitant asthma. This suggests exhaled nitric oxide may show utility as a parameter to monitor the severity of allergic rhinitis and to monitor the efficacy of the treatment. Physicians should consider comorbid AR when utilizing exhaled nitric oxide as a monitoring parameter in the treatment of asthma.

Skin prick test reactivity to aeroallergens in adult allergy clinic in Thailand: a 12-year retrospective study

Background

The global prevalence of allergic rhinitis, asthma, and atopic dermatitis has risen significantly over the last 2 decades. Allergic sensitization to aeroallergen is a major risk factor in developing the allergic disease. The prevalence of aeroallergen sensitization varies in different regions and countries.

Objective

To determine the prevalence of common aeroallergen sensitization and the atopic status among adult patients.

Methods

A cross-sectional, retrospective study. The data were collected from medical records and database of the result of skin prick test of patients who had the allergic symptoms or chronic urticaria in adult allergy clinic, Ramathibodi hospital from January 2004 to December 2015.

Results

A total of 1,516 of patients (female, 1,118 [73.7%]) were enrolled. The mean ages of participants were 41.34 (standard deviation, ±16.5) years. Fifty-eight percent (58%) of patients were diagnosed with allergic rhinitis, 19.7%, 3.2%, and 9.2% with asthma, atopic dermatitis, and chronic urticaria respectively. In the chronic urticaria group, 57.4% underwent the positive skin prick test to common aeroallergens. Mites were responsible for the most common inhaled allergen sensitization in this study as 50.1% of Dermatophagoides pteronyssinus, 32% of Dermatophagoides farinae, and 31.5% of house dust. Cockroach was the second most common aeroallergen sensitization as 32.3% followed by grass pollen, Bermuda (21.1%) and timothy (13.6%). The animal dander, cat and dog, occupied 12.9 and 10% respectively.

Conclusion

Mites were the most common cause of aeroallergen sensitization in all patients followed by cockroach, grass pollen, and animal dander. However, Bermuda sensitization has increased significantly in the last 6 years.

Cost-effectiveness of budesonide/formoterol maintenance and rescue therapy in Thailand

Background: The prevalence of asthma has increased significantly in Thailand. Budesonide/formoterol maintenance and reliever therapy has been available for several years. However, cost-effectiveness of such treatment has never been examined in Thailand. Objective: Design a cost-effectiveness (CE) analysis conducted from a Thai healthcare perspective as a piggyback study accompanying a recent clinical trial. Methods: The CE analysis was conducted from the healthcare provider’s perspective. Data were collected from a six-month, double-blind, multi-national study involving 3321 symptomatic asthma patients randomized to either: bud/form maintenance and reliever therapy, bud/form 320/9 μg bid plus terbutaline as needed, or salmeterol/ fluticasone (salm/flut) 25/125 μg two inhalations bid plus terbutaline as needed. Efficacy was determined as the number of exacerbations per patient during a six-month period. Thai unit costs were collected from the national sources and expert opinions, and applied to the resource use data for a deterministic economic evaluation. Results: There were significantly fewer exacerbations in the bud/form maintenance and reliever therapy (0.12 events/patient/6 months) group vs. the bud/form (0.16 events/patient/6 months, p <0.01), or salm/flut groups (0.19 events/patient/6 months, p <0.001). Total direct costs (healthcare visits and drug costs) were 27.0% and 5.9% lower in the bud/form maintenance and reliever therapy group than in the bud/form and salm/flut groups, respectively. Conclusion: Bud/form maintenance and reliever therapy was associated with significantly fewer exacerbations, compared to other fixed combination treatments in a recent multi-national clinical trial. This might result in lower direct costs if applied to the Thai healthcare system.

Thai pediatricians' current practice toward childhood asthma

BACKGROUND

Childhood asthma is a substantial health burden in Thailand. Due to a lack of pediatric respiratory specialists (pediatric pulmonologists and allergists; RS), most Thai children are cared for by general pediatricians (pediatric primary care providers (PCP)).

OBJECTIVES

We investigated whether current practices of Thai pediatricians complied with asthma guidelines and compared practices (diagnosis and treatments) provided by PCP and RS.

METHODS

A cross-sectional study was conducted using electronic surveys including four case scenarios of different asthma phenotypes distributed to Thai pediatricians. Asthma diagnosis and management were evaluated for compliance with standard guidelines. The practices of PCP and RS were compared.

RESULTS

From 800 surveys distributed, there were 405 respondents (51%). Most respondents (81%) were PCP, who preferred to use clinical diagnosis rather than laboratory investigations to diagnose asthma. For acute asthmatic attacks, 58% of the pediatricians prescribed a systemic corticosteroid. For uncontrolled asthma, 89% of the pediatricians prescribed at least one controller. For exercise-induced bronchospasm, 55% of the pediatricians chose an inhaled bronchodilator, while 38% chose a leukotriene receptor antagonist (LTRA). For virus-induced wheeze, 40% of the respondents chose an LTRA, while 15% chose inhaled corticosteroids (ICS). PCP prescribed more oral bronchodilators (31% vs. 18%, p = 0.02), antibiotics (20% vs. 6%, p < 0.001), and antihistamines (13% vs. 0%, p = 0.02) than RS for the management of an acute asthmatic attack.

CONCLUSIONS

Most of the Thai pediatricians' practices toward diagnosis and treatment of acute asthmatic attack and uncontrolled asthma conform to the guidelines. PCP prescribed more oral bronchodilators, antibiotics, and antihistamines than RS.

Prevalence of food allergies in South Asia

OBJECTIVE

To evaluate the published medical literature on the prevalence and types of food allergies in South Asia.

DATA SOURCES

A PubMed search was performed using the keywords India and food allergy, Asia and food allergy, and South Asia and food allergy for any period. Articles cited in selected studies were reviewed for their appropriateness of inclusion into this review.

STUDY SELECTIONS

Publications were included that were original research and fit the topic of food allergy and South Asia. South Asia is defined as region inclusive of India, Pakistan, Bangladesh, and Sri Lanka.

RESULTS

A total of 169 articles were initially identified, and 47 were reviewed in detail for inclusion in this review. The primary focus was placed on 10 studies that consisted of case reports of newly reported or documented food allergy, survey studies that investigated food allergy prevalence in specific demographics, and prospective and cross-sectional studies with case controls, all of which investigated food allergy prevalence by allergy testing in a selected population.

CONCLUSION

The medical literature on the prevalence and types of food allergy in South Asia indicates that there is a variety of unusual and unique allergens and an overall low incidence of food allergy. There is also an association of increased food allergy prevalence in individuals who live in metropolitan regions or who migrate to communities that have adopted westernization.

Burden of respiratory disease in Thailand: Results from the APBORD observational study

Asia-Pacific Burden of Respiratory Diseases (APBORD) was a cross-sectional, observational study examining the burden of respiratory disease in adults across 6 Asia-Pacific countries.This article reports symptoms, healthcare resource utilization (HCRU), work impairment and cost burden associated with allergic rhinitis (AR), asthma, chronic obstructive pulmonary disease (COPD), and rhinosinusitis in Thailand.Consecutive participants aged ≥18 years with a primary diagnosis of AR, asthma, COPD, or rhinosinusitis were enrolled at 4 hospitals in Thailand during October 2012 and October 2013. Participants completed a survey detailing respiratory symptoms, HCRU, work productivity, and activity impairment. Locally sourced unit costs were used in the calculation of total costs.The study enrolled 1000 patients. The most frequent primary diagnosis was AR (44.2%), followed by rhinosinusitis (24.1%), asthma (23.7%), and COPD (8.0%). Overall, 316 (31.6%) of patients were diagnosed with some combination of the 4 diseases. Blocked nose or congestion (17%) and cough or coughing up phlegm (16%) were the main reasons for the current medical visit. The mean annual cost for patients with a respiratory disease was US$1495 (SD 3133) per patient. Costs associated with work productivity loss were the principal contributor for AR and rhinosinusitis patients while medication costs were the highest contributor for asthma and COPD patients.The study findings highlight the burden associated with 4 prevalent respiratory diseases in Thailand. Thorough investigation of concomitant conditions and improved disease management may help to reduce the burden of these respiratory diseases.

Sinusitis, Rhinitis, Asthma, and the Single Airway Hypothesis

The one airway, one disease hypothesis proposes that the upper and lower airways share the same physiology and histomorphology. Epidemiological clinical studies support a link between rhinosinusitis and asthma. The relationship can occur in both directions, with nasal allergen challenge leading to inflammatory changes in the lower airway and bronchoprovocation studies of the lower airway leading to inflammatory changes in the upper airway. In addition, both similarities and differences exist in the pathogenesis of nasal polyps and asthma. The mechanism for the connection between the upper and lower airways is a matter of great debate. It has been proposed that inflammatory changes in the lower airway may lead to systemic inflammatory effects that play a role in increased bronchial hyperresponsiveness. Similarly, lower airway inflammatory changes may affect nasal airway patency via systemic effects. Moreover, nasopharyngeal-bronchial reflexes may play a non-immunologic role in the interaction between the lower and upper airways. An example of the connection between the upper and lower airways is found in aspirin-exacerbated respiratory disease whereby leukotrienes play a role in the pathology of chronic rhinosinusitis with polyps and asthma. It is also been observed that the treatment of asthma is hindered by untreated rhinosinusitis.

A global survey of changing patterns of food allergy burden in children

While food allergies and eczema are among the most common chronic non-communicable diseases in children in many countries worldwide, quality data on the burden of these diseases is lacking, particularly in developing countries. This 2012 survey was performed to collect information on existing data on the global patterns and prevalence of food allergy by surveying all the national member societies of the World Allergy Organization, and some of their neighbouring countries. Data were collected from 89 countries, including published data, and changes in the health care burden of food allergy. More than half of the countries surveyed (52/89) did not have any data on food allergy prevalence. Only 10% (9/89) of countries had accurate food allergy prevalence data, based on oral food challenges (OFC). The remaining countries (23/89) had data largely based on parent-reporting of a food allergy diagnosis or symptoms, which is recognised to overestimate the prevalence of food allergy. Based on more accurate measures, the prevalence of clinical (OFC proven) food allergy in preschool children in developed countries is now as high as 10%. In large and rapidly emerging societies of Asia, such as China, where there are documented increases in food allergy, the prevalence of OFC-proven food allergy is now around 7% in pre-schoolers, comparable to the reported prevalence in European regions. While food allergy appears to be increasing in both developed and developing countries in the last 10-15 years, there is a lack of quality comparative data. This survey also highlights inequities in paediatric allergy services, availability of adrenaline auto-injectors and standardised National Anaphylaxis Action plans. In conclusion, there remains a need to gather more accurate data on the prevalence of food allergy in many developed and developing countries to better anticipate and address the rising community and health service burden of food allergy.

The effect of vitamin d status on pediatric asthma at a university hospital, Thailand

Purpose

In the USA and Europe, hypovitaminosis D is associated with increased asthma severity, emergency department (ED) visit, and impaired pulmonary function in asthmatic patients. However, in tropical countries, data on the effect of vitamin D status on asthma is limited. This study evaluates the relationship between vitamin D status and the level of asthma control as well as other asthmatic parameters.

Methods

Asthmatic children were evaluated for serum 25-hydroxyvitamin D, pulmonary function tests, a skin prick test, and the level of asthma control.

Results

A total of 125 asthmatic children were recruited (boys, 66.4%). Their mean age±SD was 10.8±3.0 years. Vitamin D statuses were: deficiency (<20 ng/mL) in 19.2% of the patients, insufficiency (20-30 ng/mL) in 44.8%, and sufficiency (>30 ng/mL) in 36%. The vitamin D levels were 25.9±9.4 ng/mL in uncontrolled patients, 29.2±8.6 ng/mL in partly controlled patients, and 27.9±8.0 ng/mL in controlled patients (P>0.05). There were no significant differences in pulmonary function, asthma exacerbation, inhaled-corticosteroid (ICS) dose, anti-inflammatory drugs, or ED visit or hospitalization between different vitamin D statuses. Vitamin D deficiency patients were older and had a delayed onset of asthma than insufficiency or sufficiency patients. There was no significant correlation between serum vitamin D and pulmonary function/doses of ICS.

Conclusions

High prevalences of vitamin D deficiency and insufficiency were found in asthmatic children in Thailand; however, there was no significant relationship between vitamin D status and the level of asthma control or other asthma parameters.

The development of allergic rhinitis in children previously diagnosed as nonallergic rhinitis

BACKGROUND

Nonallergic rhinitis (NAR) is characterized by nasal symptoms similar to allergic rhinitis (AR) without an IgE-mediated immune response. Limited data are available on the natural history of NAR in its progression toward AR, particularly in children. This study evaluates the development of AR in children who were previously diagnosed with NAR.

METHODS

Children with the diagnosis of NAR during the period of 2005-2007 were reevaluated in 2010. Nasal symptoms, disease severity, comorbidities, rescue medication scores (RMSs), and skin-prick test to aeroallergens were assessed.

RESULTS

We recruited 175 children with an early diagnosis of NAR. The median age was 5.7 years, 62.9% were boys and 45.7% had family history of atopy. At reevaluation, 41% of children with previously diagnosed NAR developed sensitization to aeroallergens and were reclassified as having AR. The most frequent aeroallergen sensitization was Dermatophagoides pteronyssinus (59.7%), followed by Dermatophagoides farinae (54.2%) and American cockroach (38.9%). Children who developed AR had more nasal/eye symptoms, higher severity, and RMSs than children who did not develop AR. The predictors of developing AR were persistent nasal symptoms (adjusted odds ratio [OR], 8.9; 95% CI, 3.2-24.6), nasal itching (adjusted OR, 3.4; 95% CI, 1.2-9.5), triggered by house dust (adjusted OR, 4.3; 95% CI, 1.6-11.9) and animal danders (adjusted OR, 15.8; 95% CI, 3.3-76.1), and family history of atopy (adjusted OR, 6.0; 95% CI, 2.3-15.9).

CONCLUSION

Children with NAR who had family history of atopy, persistent nasal symptoms, and symptoms triggered by aeroallergens should be reevaluated periodically for the development of AR. This study was part of the clinical trial NCT01068808 registered in www.clinicaltrials.gov.

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.

Investigating international time trends in the incidence and prevalence of atopic eczema 1990-2010: a systematic review of epidemiological studies

The prevalence of atopic eczema has been found to have increased greatly in some parts of the world. Building on a systematic review of global disease trends in asthma, our objective was to study trends in incidence and prevalence of atopic eczema. Disease trends are important for health service planning and for generating hypotheses regarding the aetiology of chronic disorders. We conducted a systematic search for high quality reports of cohort, repeated cross-sectional and routine healthcare database-based studies in seven electronic databases. Studies were required to report on at least two measures of the incidence and/or prevalence of atopic eczema between 1990 and 2010 and needed to use comparable methods at all assessment points. We retrieved 2,464 citations, from which we included 69 reports. Assessing global trends was complicated by the use of a range of outcome measures across studies and possible changes in diagnostic criteria over time. Notwithstanding these difficulties, there was evidence suggesting that the prevalence of atopic eczema was increasing in Africa, eastern Asia, western Europe and parts of northern Europe (i.e. the UK). No clear trends were identified in other regions. There was inadequate study coverage worldwide, particularly for repeated measures of atopic eczema incidence. Further epidemiological work is needed to investigate trends in what is now one of the most common long-term disorders globally. A range of relevant measures of incidence and prevalence, careful use of definitions and description of diagnostic criteria, improved study design, more comprehensive reporting and appropriate interpretation of these data are all essential to ensure that this important field of epidemiological enquiry progresses in a scientifically robust manner.

Efficacy of buffered hypertonic saline nasal irrigation in children with symptomatic allergic rhinitis: a randomized double-blind study

BACKGROUND

Nasal irrigation has been used as an adjunctive therapy of allergic rhinitis (AR). Available evidence suggested that buffered hypertonic saline (BHS) is superior to buffer normal saline (BNS) for relief nasal symptoms.

OBJECTIVE

To evaluate the effectiveness of BHS nasal irrigation in the management of children with symptomatic AR.

DESIGN

This was a randomized, prospective, double-blind placebo-controlled study.

METHODS

The present study was a randomized prospective double-blind placebo-controlled study. Eighty-one children with symptomatic AR who had a total nasal symptom score (TNSS)≥4 were included in this study. Each participant was randomly treated with either normal saline (NSS) or BHS by a blinded investigator. Nasal saccharine clearance time (SCT) and TNSS were measured before and 10 min after nasal irrigation. Quality of life (QoL) was assessed using the questionnaire for Thai allergic rhinoconjunctivitis patients (Rcq-36). The 7-point Likert scale for satisfaction was also performed. All participants were assigned to perform nasal irrigation twice daily for the period of 4 weeks. During this period, they recorded TNSS, side effects and antihistamine use on daily diary card. A physical examination and subjective evaluation were performed at 2nd and 4th week visits, and daily diary cards were collected.

RESULTS

Patients with BHS were significantly improved in SCT (39.2% versus 15.5%, P=0.009) and TNSS (82.7% versus 69.3%, P=0.006) compared to the NSS group. However, at 2nd and 4th week both groups had improvement in TNSS and QoL compared to baseline visit. There was a significant improvement in mean QoL score in BHS group at 2nd week visit compared to NSS group (P=0.04) but not at the 4th week. Nasal congestion but not TNSS was significantly improved in the BHS group (P=0.04). Moreover, a decreased use of oral antihistamine was observed in BHS group (P=0.04). There were few complaints reported, and side effects were seen equally in both groups.

CONCLUSION

Nasal irrigation with BHS causes an improvement in SCT, TNSS and QoL compare to NS in children with symptomatic AR.

Carotenoid intake and asthma prevalence in Thai children

Several antioxidant nutrients have been described to inversely correlate with asthma. In order to quantify the intake of these substances, it is possible to measure skin levels by Raman spectroscopy, a novel non-invasive technique that can also be used in children. This cross-sectional school-based study involved 423 children from a rural area of Thailand. Asthmatic children were diagnosed according to a Health Interview for Asthma Control questionnaire. Skin carotenoid levels were measured with Raman spectroscopy. Demographic data were obtained by directly interviewing children and their parents, whereas anthropometric parameters were measured by trained staff. Intake of carotenoids, vitamin A and C were evaluated by a food frequency questionnaire. Overall incidence of asthma in Thai schoolchildren (aged 3.5-17.8 years) was 17.3%. There was no significant difference in dietary intake of carotenoids and vitamin A and C, and skin carotenoid level between asthmatic and non-asthmatic children. Skin carotenoid level significantly correlated with all carotenoids and vitamin A intake (P<0.05). Carotenoids and vitamin A and C intakes, and skin carotenoid levels were not associated with the risk of asthma in Thai children. Skin carotenoids correlated with all carotenoids and vitamin A intake in mild to moderate degrees. Raman spectroscopy was confirmed to be a useful tool to determine antioxidant skin levels.

Food allergy: riding the second wave of the allergy epidemic

Food allergy is a substantial and evolving public health issue, recently emerging over the last 10-15 yr as a 'second wave' of the allergy epidemic. It remains unclear why this new phenomenon has lagged decades behind the 'first wave' of asthma, allergic rhinitis and inhalant sensitization. In regions like Australia, which lead the respiratory epidemic, challenge-proven IgE-mediated food allergy now affects up to 10% of infants. Although their parents were among the first generation to experience the large-scale rise in allergic diseases, disorders of oral tolerance were previously uncommon. Of further concern, this new generation appears less likely to outgrow food allergy than their predecessors with long-term implications for disease burden. Allergic disease has been linked to the modern lifestyle including changing dietary patterns, changing intestinal commensal bacteria and vehicular pollution. It is not yet known whether the rise in food allergy is a harbinger of earlier and more severe effects of these progressive environmental changes or whether additional or unrelated lifestyle factors are implicated. New studies suggest environmental factors can produce epigenetic changes in gene expression and disease risk that may be potentially heritable across generations. The rising rates of maternal allergy, a strong direct determinant of allergic risk, could also be amplifying the effect of environmental changes. Preliminary evidence that non-Caucasian populations may be even more susceptible to the adverse effects of 'westernisation' has substantial global implications with progressive urbanization of the more populous regions in the developing world. Unravelling the environmental drivers is critical to curtail a potential tsunami of allergic disease.

Air pollution-related peak expiratory flow rates among asthmatic children in Chiang Mai, Thailand

The severity of air pollution in northern Thailand has long been recognized; in spite of that there have been no epidemiological studies regarding the associations between the air pollution and health effects in the area. The authors followed a cohort of 31 asthmatic children (4-11 years of age) residing in Muang district, Chiang Mai, Thailand, from 29 August 2005 to 30 June 2006, for 306 days. The daily air pollutants, including particulate matter with aerodynamic diameter < 2.5 microm, particulate matter with aerodynamic diameter < 10 microm, carbon monoxide, ozone (O(3)), nitrogen dioxide, and sulfur dioxide (SO(2)), and the meteorological parameters, including pressure, temperature, relative humidity, rain quantity, and sunshine duration, were recorded. The peak expiratory flow rates (PEFRs) were fitted with pollutants and meteorological covariates using general linear mixed models to account for random effects and autocorrelation. The authors found that there were inverse associations of SO(2) and evening PEFR, with a coefficient of -2.12 (95% confidence interval (CI) = -3.22 to -0.28); of SO(2) and daily percent deviation of PEFR, with a coefficient of -0.73 (95% CI = -1.33 to -0.12); and of O(3) combining with SO(2) and daily average PEFR, with a coefficient of -0.16 (95% CI = -0.31 to -0.00) and -1.60 (95% CI = -3.10 to -0.11), respectively. The associations of O(3) and SO(2) with PEFR were found even when SO(2) concentrations never exceeded the standard level.

Is the prevalence of asthma declining? Systematic review of epidemiological studies

Asthma prevalence has increased very considerably in recent decades such that it is now one of the commonest chronic disorders in the world. Recent evidence from epidemiological studies, however, suggests that the prevalence of asthma may now be declining in many parts of the world, which, if true is important for health service planning and also because this offers the possibility of generating and testing new aetiological hypotheses. Our objective was to determine whether the prevalence of asthma is declining worldwide. We undertook a systematic search of EMBASE, Medline, Web of Science and Google Scholar, for high quality reports of cohort studies, repeat cross-sectional studies and analyses of routine healthcare datasets to examine international trends in asthma prevalence in children and adults for the period 1990-2008. There were 48 full reports of studies that satisfied our inclusion criteria. The large volume of data identified clearly indicate that there are, at present, no overall signs of a declining trend in asthma prevalence; on the contrary, asthma prevalence is in many parts of the world still increasing. The reductions in emergency healthcare utilization being reported in some economically developed countries most probably reflect improvements in quality of care. There remain major gaps in the literature on asthma trends in relation to Africa and parts of Asia. There is no overall global downward trend in the prevalence of asthma. Healthcare planners will for the foreseeable future, therefore, need to continue with high levels of anticipated expenditure in relation to provision of asthma care.

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.

Efficacy of cefditoren pivoxil and amoxicillin/clavulanate in the treatment of pediatric patients with acute bacterial rhinosinusitis in Thailand: a randomized, investigator-blinded, controlled trial

BACKGROUND

The recommended treatment for acute bacterial rhinosinusitis in adults and children is 10 to 14 days of high doses of oral cephalosporins or amoxicillin/clavulanate.

OBJECTIVE

This study compared the clinical efficacy and tolerability of cefditoren pivoxil and amoxicillin/clavulanate in children with uncomplicated acute bacterial rhinosinusitis.

METHODS

This was a randomized, investigator-blinded, controlled study in pediatric patients (age 1-15 years) with clinical and radiographic signs and symptoms of acute rhinosinusitis. Patients were allocated to receive either cefditoren (8-12 mg/kg daily) or amoxicillin/clavulanate (80-90 mg/kg amoxicillin daily) for 14 days. Changes in sinus symptoms were assessed daily by patients or their parents using a quantitative symptom score (the S5 score). Rates of improvement, the primary efficacy measure, were also evaluated by the study investigators 7 and 14 days after the initial visit. Secondary outcome measures included time to improvement, adverse effects, and rates of relapse (assessed at days 21 and 28) and recurrence (assessed at day 60) of sinus symptoms. Relapse was defined as a subjective rating of lack of improvement at day 21 or 28 in a patient rated as improved on day 14, and recurrence was defined as sinus symptoms lasting for >or=10 days during the second month of follow-up in a patient rated as improved on day 28. Time to improvement was defined as the number of days between the initial visit and the time at which caregivers noted an improvement in patients' symptoms. Adverse events were monitored by parents/caregivers using a self-administered questionnaire and were also elicited by telephone contact.

RESULTS

The study enrolled 142 pediatric patients: 70 in the cefditoren group (42 males, 28 females; median age, 7.15 years) and 72 in the amoxicillin/clavulanate group (37 males, 35 females; median age, 6.60 years). Four patients in the cefditoren group were excluded from the study analyses (2 who were noncompliant [used <80% of the assigned medication] and 2 who developed infection at other sites). There were no significant differences in baseline medical history or signs and symptoms between the 2 groups. Rates of improvement at day 14 in the cefditoren and amoxicillin/clavulanate groups were 78.8% (52/66) and 84.7% (61/72), respectively (P = NS). There was no significant difference in the change in S5 scores between groups at day 14. The median time to improvement was 3.0 days in both groups. There were no significant differences between groups in rates of relapse (9.1% and 11.1%) or recurrence (3.0% and 5.6%) of sinus symptoms. The most common adverse event in both groups was diarrhea, occurring in 4.5% of the cefditoren group and 18.1 % of the amoxicillin/clavulanate group (P = 0.02).

CONCLUSION

In these children with acute bacterial rhinosinusitis, there were no significant differences between cefditoren and amoxicillin/clavulanate, the currently recommended treatment, in terms of rates of response, relapse, or recurrence.

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.