Sensitization to dust mites in children with allergic rhinitis in Singapore: does it matter if you scratch while you sneeze?

House dust mite allergy in Malaysia: review of research gaps in the current scenario and the way forward

The prevalence of house dust mite (HDM) allergy, especially in Asian countries with rapid urbanization, has been increasing. House dust mites thrive in places with relatively high humidity. With the combination of climate change, naturally high humidity, and urbanization, tropical countries like Malaysia are becoming a hotspot for HDM allergy fast. With a previously reported sensitization rate of between 60 and 80%, it is a worrying trend for Malaysia. However, due to incomplete and out-of-date data, as seen by the limited study coverage in the past, these numbers do not paint a complete picture of the true HDM allergy scene in Malaysia. This review briefly discusses the HDM fauna, the HDM sensitization rate, the common diagnosis and therapeutic tools for HDM allergy in Malaysia, and makes suggestions for possible improvements in the future. This review also highlights the need of more comprehensive population-based prevalence studies to be done in Malaysia, encompassing the three main HDMs-Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis-as the lack of up-to-date studies failed to give a clearer picture on the current scenario of HDM allergy in Malaysia. Future studies will be beneficial to the nation in preparing a better blueprint for the management and treatment of HDM allergy.

Prevelance of Common Aeroallergens in Allergic Rhinitis and its Correlation with Bronchial Asthma: A Study on 798 Patients by Skin Prick Test

Allergic rhinitis affects 30% of the Indian population (Dey et al. in Int Arch Allergy Immunol 178:60-65, 2019). Patients can be sensitive to single or multiple allergens. Polysensitization is more common (Bousquet et al. in Ann Epidemiol 20:797-803, 2010; Arbes et al. in J Allergy Clin Immunol 116:377-383, 2005). Sensitization to multiple allergens may have a role in the severity and the association of Asthma in such patients. A total of 798 patients with allergic rhinitis (SFAR ≥ 7) were included. Disease severity and associated symptoms were evaluated using questionnaire. Each patient underwent a Skin prick test with an allergen panel of 35 allergens each (Annesi-Maesano et al. in Allergy 57:107-114, 2002) and the results were evaluated to study the association of asthma and severity of Allergic rhinitis. Data consisting of 389 (48.7%) males and 409 (51.3%) females were assessed. A total of 82.2% of the study population of symptomatic patients were sensitized to at least one of the allergens. Seventy patients (8.78%) had associated asthma. Forty-four patients were polysensitized and fifteen were mono sensitized. Among polysensitized patients, 36 patients had sensitization to at least 6 different allergens. Dermatophagoides pteronyssinus was the most common allergen among asthma patients. This study provides a thorough knowledge of locally prevalent aeroallergens which is essential for the prompt diagnosis and treatment of allergic patients. Skin prick test can be a non-invasive vital tool in analyzing patterns of allergen exposure, the prevalence of allergen, sensitizing potential of different allergens in that specific geographic area.

Blood eosinophil related to maternal allergic rhinitis is associated with the incidence of allergic rhinitis in offspring: COCOA study

OBJECTIVE

The identification of allergic rhinitis (AR) in early life is important for the target of intervention. AR is caused by various environmental factors, including house dust mites. We investigated the relationship between the Dermatophagoides farinae (Der f)-IgE and eosinophil in mothers with AR at delivery and the eosinophil levels and AR incidence in children.

METHODS

The study participants were 983 mother-child pairs from the COhort for Childhood Origin of Asthma and Allergic Diseases. AR was diagnosed by a doctor at delivery in mother and at 3 years of age in offspring. The association between eosinophil level and AR was assessed using logistic regression analysis.

RESULTS

The Der f-IgE level in mother having AR at delivery was associated with the mother's eosinophil level, and the mother's eosinophil level was associated with the child's eosinophil level both at age 1 and 3. The risk of AR at age 3 in children was increased according to increased eosinophil levels in mothers at delivery and in children both aged 1 and 3 years (adjusted odds ratio [aOR] and 95% confidence interval [CI]: 2.57 [1.14-5.78], 2.28 [1.02-5.13], respectively). The risk of childhood AR at the age of 3 is increased when both mothers and children have high eosiniophils (aOR and 95% CI: 2.62 [1.01-6.79], 1.37 [0.98-1.91]).

CONCLUSIONS

Der f-IgE in mothers at delivery was related to eosinophil levels in mothers with AR and higher level of eosinophils in both mother and children was associated with the increased risk of AR incidence at the first 3 years of life of children.

Allergen Sensitization in Patients with Skin Diseases in Shanghai, China

Introduction

Allergen distribution has obvious geographical characteristics. Understanding local epidemiological data may provide evidence-based strategies for the prevention and management of disease. We investigated the distribution of allergen sensitization in patients with skin diseases in Shanghai, China.

Methods

Data from tests for serum-specific immunoglobulin E were collected from 714 patients with three skin diseases who visited the Shanghai Skin Disease Hospital from January 2020 to February 2022. The prevalence of 16 allergen species, as well as age, sex, and disease-group differences in allergen sensitization, were investigated.

Results

Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most common aeroallergen species to cause allergic sensitization in patients with skin diseases, whereas shrimp and crab were the most common food-allergen species. Children were more susceptible to various allergen species. With regard to sex differences, males were sensitized to more allergen species than females. Patients suffering from atopic dermatitis were sensitized to more allergenic species than patients with non-atopic eczema or urticaria.

Conclusion

Allergen sensitization in patients with skin diseases in Shanghai differed by age, sex, and disease type. Knowing the prevalence of allergen sensitization across age, sex, and disease type may help facilitate diagnostic and intervention efforts, and guide the treatment and management of skin diseases in Shanghai.

Clustering the Clinical Course of Chronic Urticaria Using a Longitudinal Database: Effects on Urticaria Remission

Purpose

Little is known about the clinical course of chronic urticaria (CU) and predictors of its prognosis. We evaluated CU patient clusters based on medication scores during the initial 3 months of treatment in an attempt to investigate time to remission and relapse rates for CU and to identify predictors for CU remission.

Methods

In total, 4,552 patients (57.9% female; mean age of 38.6 years) with CU were included in this retrospective cohort study. The K-medoids algorithm was used for clustering CU patients. Kaplan-Meier survival analysis with Cox regression was applied to identify predictors of CU remission.

Results

Four distinct clusters were identified: patients with consistently low disease activity (cluster 1, n = 1,786), with medium-to-low disease activity (cluster 2, n = 1,031), with consistently medium disease activity (cluster 3, n = 1,332), or with consistently high disease activity (cluster 4, n = 403). Mean age, treatment duration, peripheral neutrophil counts, total immunoglobulin E, and complements levels were significantly higher for cluster 4 than the other 3 clusters. Median times to remission were also different among the 4 clusters (2.1 vs. 3.3 vs. 6.4 vs. 9.4 years, respectively, P < 0.001). Sensitization to house dust mites (HDMs; at least class 3) and female sex were identified as significant predictors of CU remission. Around 20% of patients who achieved CU remission experienced relapse.

Conclusions

In this study, we identified 4 CU patient clusters by analyzing medication scores during the first 3 months of treatment and found that sensitization to HDMs and female sex can affect CU prognosis. The use of immunomodulators was implicated in the risk for CU relapse.

Effect of scaling and root planing on level of immunoglobulin E and immunoglobulin G4 in children with gingivitis and house-dust mite allergy: A pilot randomised controlled trial

Background and Objective: There is a pressing need for developing innovative strategies to prevent allergic diseases among children. As house-dust mite (HDM) allergy is often seen in children with gingivitis, strategies should be derived from a conceptual framework of allergen elimination and pathogen eradication; one such strategy is dental scaling and root planing (SRP) to remove dental plaque and periodontal pathogens. The study aimed to evaluate the beneficial effects of comprehensive 6-months dental SRP to reduce the level of immunoglobulin E (IgE) and immunoglobulin G₄ (IgG₄) in children with gingivitis and HDM allergy. IgE and IgG₄, whose production is controlled mainly by Th-2 cells and B cells, are proven biomarkers for atopic inflammatory responses. Methods: The present study conducted a non-blinded randomised controlled trial with superiority design. A total of 10 subjects (age range 6-16 years) with gingivitis and positive skin-prick test to HDM from Pediatric Allergy Outpatient Clinic, Dr. Soetomo General Hospital were enrolled in the present study. Of the 10 subjects, only five received dental SRP. We further evaluated total serum IgE and IgG₄ level before and 6 months after treatment. Results and Discussion: Subjects in the standard treatment group showed a slight decrease in the IgE level ([Formula: see text]) but no change in the IgG₄ level ([Formula: see text]), while subjects in the intervention group showed a significant decrease in IgE ([Formula: see text]) and IgG₄ levels ([Formula: see text]). Conclusion: The study results suggest that 6-month comprehensive dental scaling combined with root planing may help to reduce IgE and IgG₄ levels in children with gingivitis and HDM allergy. Furthermore, untreated or undertreated gingivitis is often associated with worsening allergic manifestation and thus should be avoided. Trial Registration: ISRCTN31416107, retrospectively registered on 17 April 2018.

A review of house dust mite allergy in India

House dust mites (HDMs) are extensively reported as potent allergens worldwide with India being in the top row. HDM sensitization is hugely reported from India and has led to the concern of implementing proper guidelines for treatment of the sufferers. Climatic conditions and a rapid shift of life style toward a more indoor and urbanised pattern are denoted as the probable causes of increased HDM exposure and sensitization. On the contrary, the varying rate of HDM allergy from similar climate and urbanised areas throughout the world suggest the influence of genetic predisposition. At present, in India, avoidance of HDM exposure is recommended as the baseline defence. Allergen immunotherapy (AIT) guidelines are proposed in India to maintain uniformity in the diagnosis techniques and management strategies throughout the country. Considering the genetic susceptibility toward allergic diseases, the concept of 'personalised medicine' is preferred over the 'mass targeted treatment'. From the Indian perspective, the present problem is Dermatophagoides pteronyssinus and D. farinae allergens are not well characterised at the molecular level. As a consequence, India is still reliant on less standardised allergen extracts. The proper identification, purification, and molecular characterization of HDM allergens can combat this problem. In this review, we aimed to portray a complete account of HDM allergy in India with respect to prevalence, probable triggers, diagnosis and therapy. We have attempted to present the current ambiguities along with the likely deciphering that would pave the way to solve HDM allergy-related queries in India.

House Dust Mite Allergy Under Changing Environments

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

Conformational IgE Epitope Mapping of Der p 2 and the Evaluations of Two Candidate Hypoallergens for Immunotherapy

Epitope mapping of Der p 2, a clinically important dust-mite allergen is the first step in designing immunotherapy hypoallergen vaccine candidates. Twenty-one single alanine mutants of Der p 2 were generated and their secondary structure was analysed using circular dichroism spectra. Only one mutant, K96A resulted in a misfolded protein. All mutants were tested for serum IgE reactivity using serum from dust mite allergic individuals by immuno dot-blots. Mutations to five residues, N10, E25, K77, K96 and E102 consistently showed reduced IgE reactions compared to wild-type Der p 2, and therefore these residues constitute the major IgE epitopes of Der p 2. Two mutants with consistent low IgE binding, K96A and E102A, were subsequently evaluated as hypoallergen candidates. IgG antibodies raised in mice against both mutants could inhibit human IgE-binding to WT Der p 2. Both mutants had intact T-cell epitopes as they were able to stimulate peripheral blood mononuclear cell proliferation similar to WT Der p 2. However, a switch in Th1:Th2 cytokine profile was not observed. In summary, we have identified the major conformational epitopes of Der p 2, and evaluated two Der p 2 hypoallergen vaccine candidates for immunotherapy.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

[Blomia tropicalis: A house dust mite in the tropics]

INTRODUCTION

Blomia tropicalis is a mite that belongs to the superfamily of Glycyphagidae. Initially described as a storage mite, it is now considered as a house dust mite of tropical and sub-tropical areas.

STATE OF THE ART

Sensitization to this mite is very common in South America and Southeast Asia. Epidemiological studies have also found sensitization to this mite in Africa and Central America. Blo t 5 is the major allergen of B. tropicalis. Co-sensitization to other house dust mites such as Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) is very common. Cross-reactivity has been described but recombinant allergens revealed by molecular biology techniques do not explain this cross-reactivity. Sensitization to B. tropicalis seems to begin at the age of 36 months, the incidence increases until adulthood, and decreases from the age of 50. The involvement of B. tropicalis in allergic rhinitis and asthma is well described. It is also implicated in other allergic diseases. Few studies have assessed the therapeutic strategies available against this mite but immunotherapy is widely used.

PERSPECTIVES

Studies are needed to better understand the role of B. tropicalis in human diseases and to develop specific treatments.

International consensus (ICON) on: clinical consequences of mite hypersensitivity, a global problem

Since mite allergens are the most relevant inducers of allergic diseases worldwide, resulting in significant morbidity and increased burden on health services, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), formed by the American Academy of Allergy, Asthma and Immunology (AAAAI), the American College of Allergy, Asthma and Immunology (ACAAI), the European Academy of Allergy and Clinical Immunology (EAACI), and the World Allergy Organization (WAO), has proposed to issue an International Consensus (ICON) on the clinical consequences of mite hypersensitivity. The objectives of this document are to highlight aspects of mite biology that are clinically relevant, to update the current knowledge on mite allergens, routes of sensitization, the genetics of IgE responses to mites, the epidemiologic aspects of mite hypersensitivity, the clinical pictures induced by mites, the diagnosis, specific immunotherapeutic approaches, and prevention.

Priming with high and low respiratory allergen dose induces differential CD4+ T helper type 2 cells and IgE/IgG1 antibody responses in mice

Sensitization of allergic patients normally takes place over several years and is the result of repeated exposure to low levels of allergen. Most mouse asthma models use a high dose of allergen administered over a short period. We have investigated the role of dose in the immune response to an inhaled respiratory allergen (Blomia tropicalis). We observed the effect of priming dose on the allergic response in mice intranasally immunized with low (0·5 μg) and high (50 μg) doses of B. tropicalis extract and killed 1 day after the last challenge. For both doses of allergen, T helper type 2 (Th2) cells and Th2 cytokines were evident as well as eosinophilic inflammation accompanied by mucus hyper-secretion. By contrast, IgE and IgG1 antibody responses were normally only detected at high-dose priming. To investigate the mechanism for these effects, we found group 2 innate lymphoid cells (ILC2s) were increased 48 hr after challenge in the low-dose-treated but not the high-dose-treated mice. Furthermore, we determined whether repeated low-dose exposure with different priming protocols could induce an antibody response. Repeated low-dose exposure to 0·5 μg three times weekly for 4 weeks (cumulative 6 μg) had the same effect as a shorter high-dose exposure (cumulative 80 μg) and increasing cumulative dose induced antibody responses. These data indicate that low doses of allergen are sufficient to prime Th2 cells and ILC2s, but insufficient to induce antibody responses. Cumulative exposure to small amounts of allergen induces both Th2 and antibody responses and may better reflect natural sensitization.

Vitamin D supplementation during pregnancy and infancy reduces aeroallergen sensitization: a randomized controlled trial

BACKGROUND

Vitamin D has immune-modulating effects. We determined whether vitamin D supplementation during pregnancy and infancy prevents aeroallergen sensitization and primary care respiratory illness presentations.

METHODS

A randomized, double-blind, placebo-controlled parallel-group trial. We assigned pregnant women, from 27-week gestation to birth, and then their infants, from birth to 6 months, to placebo or one of two dosages of daily oral vitamin D. Woman/infant pairs were randomized to: placebo/placebo, 1000 IU/400 IU or 2000 IU/800 IU. When the children were 18 months old, we measured serum-specific IgE antibodies and identified acute primary care visits described by the doctor to be due to a cold, otitis media, an upper respiratory infection, croup, asthma, bronchitis, bronchiolitis, a wheezy lower respiratory infection or fever and cough.

RESULTS

Specific IgE was measured on 185 of 260 (71%) enrolled children. The proportion of children sensitized differed by study group for four mite antigens: Dermatophagoides farinae (Der-f1, Der-f2) and Dermatophagoides pteronyssinus (Der-p1, Der-p2). With results presented for placebo, lower dose, and higher dose vitamin D, respectively (all P < 0.05): Der-f1 (18%, 10%, 2%), Der-f2 (14%, 3%, 2%), Der-p1 (19%, 14%, 3%) and Der-p2 (12%, 2%, 3%). There were study group differences in the proportion of children with primary care visits described by the doctor as being for asthma (11%, 0%, 4%, P = 0.002), but not for the other respiratory diagnoses.

CONCLUSIONS

Vitamin D supplementation during pregnancy and infancy reduces the proportion of children sensitized to mites at age 18 months. Preliminary data indicate a possible effect on primary care visits where asthma is diagnosed.

Sensitization Rates for Various Allergens in Children with Allergic Rhinitis in Qingdao, China

The aim of this study was to determine the prevalence of sensitization to common allergens in children with allergic rhinitis (AR) living in Qingdao, China. We conducted a retrospective analysis for AR cases, who underwent skin prick tests (SPT) in Qingdao. A total of 2841 children with AR qualified for the inclusion criteria (Age 3-5 years: 1500 children; Age 6-12 years: 1341 children). The most common inhaled allergens to which the AR children were sensitive were Dermatophagoides pteronyssinus (69.3%), Dermatophagoides farinae (66.2%) and mould 1 (Penicillium notatum 38.9%); while the corresponding ingested allergens were mussel (39.2%), shrimp (36.3%) and carp (36.5%). The prevalence of sensitization to inhaled allergens and food allergens was higher in children >6 years of age as compared to that in children 3-5 years of age (all p < 0.05). Children >6 years old were more sensitive to dust mite as compared to children 3-5 years old (p < 0.05). Sensitization to dust mite was more common in males than in females (p = 0.05). In this study, Dermatophagoides pteronyssinus and Dermatophagoides farinae were the most common allergens causing AR in children in Qingdao, China. Older children with AR, particularly males, were found to be more sensitive to dust mite.

Immunoglobulin E to allergen components of house dust mite in Korean children with allergic disease

BACKGROUND

House dust mites (HDMs) are important sources of indoor allergens. Seventeen components have been identified from Dermatophagoides pteronyssinus (Der p).

OBJECTIVE

Our aim was to define the prevalence of specific IgE to components of Der p in Korea and investigate the clinical features of them in children with allergic disease.

METHODS

We performed a prospective evaluation of 80 HDM sensitized patients with history of allergic rhinitis (AR), atopic dermatitis (AD), asthma and urticaria (UC). Patients underwent ImmunoCAP for total IgE, Der p, Der f, Der p 1, Der p 2, and Der p 10.

RESULTS

Seventy-nine patients had detectable serum IgE to Der p, 80 patients were sensitized to Der f, 66 patients were sensitized to Der p 1, 63 patients to Der p 2, and 7 patients were sensitized to Der p 10. Der p 1 specific IgE was significantly lower in the UC group compared with the AD and AR group. Total IgE was significantly higher in the Der p 10 sensitized group. Der p 10 serum IgE level was highly correlated with crab and shrimp specific IgE. There was a significant positive correlation between total IgE and specific IgE to Der p and its components and Der f.

CONCLUSION

Sensitization to HDM and its components in Korea is similar to previous studies from temperate climate. The determination of Der p 1, Der p 2, and Der p 10 specific IgE helps in obtaining additional information in regards to allergic disease.

Sensitization to airborne allergens among adults and its impact on allergic symptoms: a population survey in northern Vietnam

Background

The knowledge about allergic sensitization and its relationship with clinical symptoms and diseases among adults in South-East Asia is poor. The aim of this study was to investigate the prevalence and pattern of allergic sensitization and the association with asthma and allergic rhinitis in adults in urban and rural Vietnam.

Methods

Among 5,782 responders to a questionnaire survey in northern Vietnam, a random sample was invited to a clinical follow-up and 684 (46%) participated. The methods included a structured interview using a modified GA²LEN study questionnaire on symptoms and possible determinants for diseases. Skin prick test (SPT) with ten common airborne indoor and outdoor allergens, lung function test, and methacholine test was performed among subjects ≤60 years of age.

Results

In total, one third of subjects had a positive SPT reaction to at least one allergen, 36.9% of men and 31.0% of women (n.s.). The most common sensitizer was the storage mite B. tropicalis (men 27.7%; women 18.7%) followed by house dust mite D. pteronyssinus (men 16.5%; women 10.6%), and D. farinae (men 15.3%; women 6.3%), and cockroach (men 16.5%; women 10.2%). Sensitization to all major allergens were significantly more common among men and among subjects ≤45 years compared with women and subjects >45 years, respectively. The prevalence of sensitization to animals, pollen and molds were low. The majority of cockroach-sensitized subjects were also sensitized to mites. Sensitization to any allergen and all major allergens were significantly associated with rhinitis, but not with asthma. However, bronchial hyper-reactivity was significantly associated with increasing number of positive SPTs (p = 0.047).

Conclusions

Among adults in northern Vietnam sensitization to mite and cockroach most common in both rural and urban areas. The dominant sensitizer was the storage mite B. tropicalis, which should be included in future studies and also in clinical practice, owing to its association with clinical symptoms. As in the Western world allergic sensitization was associated with rhinitis and bronchial hyper-reactivity. The lack of association with asthma in South-East Asia needs to be studied further.

Role of skin prick test in allergic disorders: a prospective study in kashmiri population in light of review

Background:

Skin prick test (SPT) is the most effective diagnostic test to detect IgE mediated type I allergic reactions like allergic rhinitis, atopic asthma, acute urticaria, food allergy etc. SPTs are done to know allergic sensitivity and applied for devising immunotherapy as the therapeutic modality.

Materials and Methods:

This prospective study was conducted in the department of Immunology and Molecular medicine at SKIMS. A total of 400 patients suffering from allergic rhinitis, asthma and urticaria were recruited in this study. SPT was performed with panel of allergens including house dust mite, pollens, fungi, dusts, cockroach, sheep wool and dog epithelia. Allergen immunotherapy was given to allergic rhinitis and asthmatic patients as therapeutic modality.

Results:

In our study, age of patients ranged from 6 to 65 years. Majority of patients were in the age group of 20-30 years (72%) with Male to female ratio of 1:1.5. Of the 400 patients, 248 (62%) had urticaria, 108 (27%) patients had allergic rhinitis and 44 (11%) patients had asthma. SPT reaction was positive in 38 (86.4%) with allergic asthma, 74 (68.5%) patients with allergic rhinitis and 4 (1.6%) patient with urticaria, respectively. Allergen immunotherapy was effective in 58% patients with allergic rhinitis and 42% allergic asthma.

Conclusion:

Identifiable aeroallergen could be detected in 86.4% allergic asthma and 68.5% allergic rhinitis patients by SPT alone. Pollens were the most prevalent causative allergen. There was significant relief in the severity of symptoms, medication intake with the help of allergen immunotherapy.

Prevalence of allergen sensitization, most important allergens and factors associated with atopy in children

CONTEXT AND OBJECTIVE

Knowledge of the profile of allergen sensitization among children is important for planning preventive measures. The objective of this study was to assess the prevalence and profile of sensitization to inhaled allergens and food among children and adolescents in an outpatient population in the city of Palmas.

DESIGN AND SETTING

Cross-sectional study at outpatient clinics in Palmas, Tocantins, Brazil.

METHODS

Ninety-four patients aged 1-15 years who were attending two pediatric outpatient clinics were selected between September and November 2008. All of the subjects underwent clinical interviews and skin prick tests.

RESULTS

A positive skin prick test was observed in 76.6% of the participants (72.3% for inhalants and 28.9% for food allergens). The most frequent allergens were Dermatophagoides pteronyssinus (34%), cat epithelium (28.7%), dog epithelium (21.3%), Dermatophagoides farinae (19.1%), Blomia tropicalis (18.1%), cow's milk (9.6%) and grasses (9.6%). A positive skin prick test correlated with a history of atopic disease (odds ratio, OR = 5.833; P = 0.002), a family history of atopic disease (OR = 8.400; P < 0.001), maternal asthma (OR = 8.077; P = 0.048), pet exposure (OR = 3.600; P = 0.012) and cesarean delivery (OR = 3.367; P = 0.019).

CONCLUSION

Dermatophagoides pteronyssinus was the most frequent aeroallergen and cow's milk was the most prevalent food allergen. There was a positive correlation between a positive skin prick test and several factors, such as a family history of atopic disease, maternal asthma, pet exposure and cesarean delivery.

Allergic rhinitis and non-allergic rhinitis in children in the tropics: prevalence and risk associations

BACKGROUND

The age-related comparative prevalence of allergic rhinitis (AR) and non-allergic rhinitis (NAR) in children is poorly defined. We aimed to characterize AR and NAR in children.

METHODS

This study enrolled children with chronic rhinitis who presented to a tertiary paediatric center for a diagnostic skin prick test (SPT). Parents completed a medical history questionnaire for their child, including disease activity for asthma and rhinitis. Sociodemographic data was obtained and all participants underwent a common inhalant SPT panel. A positive SPT indicated AR.

RESULTS

From March 2001 to March 2009, 6,660 children (64% male) were enrolled (aged 6 months to 19 years, mean 7.82 years). Only 3.7% (249) of the children were <2 years old, and almost 30% of these had AR. Most children with AR (73%) presented after age 6. Males were more likely to have AR (vs. NAR) (OR 1.5; CI 1.39-1.77). Antihistamine and salbutamol use did not differ between children with AR and NAR. Children with AR were more likely to require adjunct therapy with inhaled corticosteroids (51.2% vs. 43.2%, P < 0.001), have drug hypersensitivity (especially antipyretic drugs) (2.5% vs. 1.3%, P = 0.384) or an asthma admission (9.1% vs. 6.0%, P < 0.001).

CONCLUSIONS

AR is more common in male children, is relatively rare below the age of 2 years, and accounts for two-thirds of all childhood chronic rhinitis and 73.3% of all chronic rhinitis in school-aged children (≥6 years old). Children with AR have more severe rhinitis symptoms and more often suffer from asthma-related events and admissions.

Prevalence of sensitization to Blomia tropicalis among young adults in a temperate climate

BACKGROUND

There are no previous population-based studies assessing the prevalence of Blomia tropicalis (BT). This investigation analyzes the prevalence of sensitization to BT and its contribution to asthma and related diseases among young adults in the Canary Islands.

MATERIAL AND METHODS

From a random sample of 9506 adults, aged between 20 and 44, who had previously answered a short respiratory questionnaire, a further 20% random sample was drawn. All participants filled in an extensive questionnaire, and they underwent spirometry and bronchial hyperresponsiveness (BHR) test and skin testing to several allergens as well as the determination of total IgE and specific IgE.

RESULTS

The prevalence of positive skin tests to BT was 13.8% (95% confidence interval [CI] 10.6-17.9%) and that of BT-specific IgE 17.9% (95% CI 14.2-24.5%). Sensitization to BT (positive skin tests or positive specific IgE) was 20.9% (95% CI 16.9-25.5%). Most of the subjects sensitized to BT were also sensitized to Dermatophagoides pteronissimus; however, only 7% displayed monosensitization to BT. Among subjects who exhibited BHR, sensitization to BT reached 46.7% (95% CI 32.7-60.9%), among those with asthma 50% (95% CI 26.8-73.2%), in subjects with rhinitis 37.2% (95% CI 28.1-47.6%), and in those suffering from dermatitis 25.9% (95% CI 18.7-34.5%). A strong association of BT sensitization with BHR and asthma before and after 15 years was found.

CONCLUSION

The prevalence of sensitization to BT among young adults in the Canary Islands is high, and it displays a close relationship with allergic respiratory diseases and dermatitis.

Mite component-specific IgE repertoire and phenotypes of allergic disease in childhood: the tropical perspective

Sensitization to perennial aeroallergens correlates with the risk of persistent asthma (AS) in children. In tropical Singapore, multiple codominant species of mites abound in the indoor environment, and preferential species-specific sensitization has been associated with different phenotypes of allergic disease. We investigated the pattern of mite component-specific IgE (mcsIgE) in children with different phenotypes of clinical allergic disease in an environment with multiple mite species exposure. A prospective evaluation of newly diagnosed patients with clinical diagnosis of allergic rhinitis (AR), atopic dermatitis (AD), or AS and sensitization to one or more aeroallergens were performed. Sera were tested for specific IgE against an extensive panel of Dermatophagoides pteronyssinus and Blomia tropicalis allergens. A total of 253 children were included, mean age 7.3 yr, 79% fulfilled criteria for AR, 46% AS, 71% AD, and 31% for all three. Sensitization to one or both mites was observed in 91% of children, 89% were sensitized to D. pteronyssinus, and 70% to B. tropicalis. The most common mite allergens recognized by these atopic children were Der p 1 (64%), Der p 2 (71%), Blo t 5 (45%), Blo t 7 (44%), and Blo t 21 (56%). Specific IgE responses to an increased number of distinct mite allergens correlated with the complexity of the allergic phenotype. In multivariate analysis, an increased risk for the multi-systemic phenotype (AR + AS + AD) was associated with sensitization to an increased repertoire of mite components (three or more) (OR 4.3, 95% CI 2.1-8.8, p = 0.001) and a positive parental history of AS (OR 2.4, 95% CI 1.2-2.9, p = 0.013). A highly pleiomorphic IgE response to the prevalent indoor mites is associated with the presence of a multi-systemic allergic phenotype in childhood in a tropical environment.

Specific profiles of house dust mite sensitization in children with asthma and in children with eczema

Sensitization to house dust mites (HDM) is highly prevalent among the young atopic population in Singapore. Previously published data suggest that individuals with skin allergies show preferred sensitization to Dermatophagoides pteronyssinus while individuals with pure respiratory allergies show preferred sensitization to Blomia tropicalis. The aim of our study was to compare the sensitization profiles between children with asthma and those with eczema to D. pteronyssinus and B. tropicalis and their specific allergens. A total of 60 children, 30 with asthma and 30 with eczema were recruited. IgE levels specific for a panel of HDM allergens from the two mite species were measured using enzyme-linked immunosorbent assay. The asthma group showed highest sensitization to Blo t5 while the eczema group showed highest sensitization to Der p5. Comparison between the two disease groups showed that the eczema group had significantly higher IgE levels for Der p (p = 0.042) and its allergens Der p1 (p = 0.019) and Der p5 (p = 0.001). Generally, the eczema group was more sensitized to the panel of allergens compared to the asthma group. Individuals with asthma and those with eczema showed different sensitization profiles to HDM. These findings highlighted possible mechanisms for different manifestation of allergy.

A multicentre study assessing the prevalence of sensitizations in patients with asthma and/or rhinitis in China

BACKGROUND

The prevalence of sensitization in patients with asthma and rhinitis in mainland China remains unclear.

OBJECTIVE

Our aim was to estimate the prevalence of allergy in patients with respiratory allergic diseases such as asthma and/or rhinitis attending respiratory clinics within mainland China. The study also investigated regional and annual differences in the prevalence and pattern of sensitization among the patients in China.

METHOD

A cross-sectional survey was performed in 6304 patients suffering from asthma and/or rhinitis in 17 cities from 4 regions of China. Patients completed a standardized questionnaire asking for the presence of respiratory and allergic symptoms. They also underwent skin prick tests with 13 common aeroallergens.

RESULTS

Among the 6304 patients, 4545 (72.1%) had at least one positive skin prick reaction. The overall prevalence of positive skin prick responses was 59.0% for Dermatophagoides farinae, 57.6% for Dermatophagoides pteronyssinus, 40.7% for Blomia tropicalis, 16.1% for American cockroach, 14.0% for dog, 11.5% for Blatella germanica, 11.3% for Artemisia vulgaris, 10.3% for cat, 6.5% for Ambrosia artemisifolia, 6.3% for mixed mould I, 4.4% for mixed mould IV, 3.5% for mixed grass pollen and 2.2% for mixed tree pollen. Sensitizations to common allergens varied widely between geographical areas and demonstrated unique pattern in patients by stratification with age groups, with asthma and/or rhinitis. Severity of rhinitis and asthma was significantly correlated with skin index of reactivity to Artemisia vulgaris, Ambrosia artemisifolia and to D. pteronyssinus, D. farinae and Blomia tropicalis respectively (P < 0.001). Positive reactivity to the tested allergens and concomitant reactivity to multiple allergens including to house dust mites and Blomia tropicalis was markedly increased in patients with both asthma and rhinitis.

CONCLUSION

House dust mites were the most prevalent allergens in patients with asthma and/or rhinitis in China. There were significant differences in patterns of sensitizations in patients from different geographical areas, age groups as well as asthma and/or rhinitis.

Joint effect of asthma/atopy and an IL-6 gene polymorphism on lung cancer risk among lifetime non-smoking Chinese women

Recent evidence suggests that inflammatory pathways are important mediators of carcinogenesis. Asthma, allergic rhinitis and atopic dermatitis are clinical manifestations of a systemic atopic disorder, which is associated with airway hyper-responsiveness and inflammation. We examined the effect of a history of asthma/atopy among 132 lung cancer cases (of which 72% were adenocarcinomas) and 163 controls, all of whom were non-smoking Chinese women, in combination with a single nucleotide polymorphism (-634C/G) in the interleukin-6 (IL-6) gene which regulates secretion of a pro-inflammatory cytokine found to be predominant in lung tumour tissue. We observed a slight increase in risk of lung cancer [odds ratio, OR = 1.5, 95% confidence interval (95% CI) = 0.8-2.6] and of adenocarcinoma (OR = 1.6, 95% CI = 0.9-3.1) with asthma/atopy alone. There was no effect of the IL-6 CG/GG genotype on lung cancer risk on its own. Among individuals with both asthma/atopy and the IL-6 -634 G allele, however, risk was increased at least 3-fold (OR = 3.1, 95% CI = 1.2-8.3 for all cancers and OR = 4.2, 95% CI = 1.5-11.6 for adenocarcinomas) relative to individuals with no asthma/atopy and the CC genotype. On stratified analysis, a significant increase in risk with asthma/atopy was restricted to those with the at-risk genotype (Pint < 0.05). Our findings are consistent with the role of chronic inflammation as an aetiologic factor among non-smoking Asian women, and suggest that asthma/atopy is a risk marker for susceptibility to the development of lung cancer.