Related Articles

Objective

Allergic sensitization is very prevalent and often precedes the development of allergic disease. This study examined the association of race with allergic sensitization among healthy children with no family history of atopy.

Study design

275 children, predominantly from lower socioeconomic strata, from Cincinnati, OH aged 2 to 18 years without a family or personal history of allergic diseases, underwent skin prick testing to eleven allergen panels. The Pediatric Allergic Disease Quality of Life Questionnaire (PADQLQ) was used to examine the impact of sensitization on quality of life.

Results

39% of healthy children were sensitized to ≥1 allergen panels. Multivariate logistic regression showed increased risk among African American children for any sensitization (OR 2.17; [95% CI; 1.23, 3.84]) and sensitization to any outdoor allergen (OR 2.96 [95% CI; 1.52, 5.74]). 86% of children had PADQLQ scores ≤1 (0 to 6 scale).

Conclusion

Allergic sensitization is prevalent even among children who do not have a personal or family history of asthma, allergic rhinitis, or atopic dermatitis, and who have no evidence of current even subtle effects from this sensitization on allergic-disease related quality of life. African American children are at greater risk for presence of sensitization, especially to outdoor allergens.

Background:

Allergic disease is on the rise worldwide. Effective prevention of allergic disease requires comprehensive understanding of the factors that contribute to its intermediate phenotypes, such as sensitization to common allergens.

Objective:

To estimate the degree of genetic and environmental contributions to sensitization to food or aeroallergens.

Methods:

Sensitization was defined as a positive skin prick test to an allergen. We calculated the zygosity-specific concordance rates and odds ratios (ORs) for sensitization to food and aeroallergens in 826 Chinese twin pairs (472 MZ and 354 DZ) aged 12 to 28 years. We also applied structural equation modeling procedures to estimate genetic and environmental influences on sensitization.

Results:

The concordance rates and risk of sensitization in one twin given the presence vs. the absence of sensitization in the other twin were higher in MZ twins than those in DZ twins. However, a large number of MZ twins were discordant in sensitization to common allergens. These observations suggest both genetic and environmental factors influence sensitization. Consistently, the estimated heritability and individual environmental components of the liability to sensitization ranged from 0.51 to 0.68 and 0.32 to 0.49, respectively, based on the best-fitted structural equation model. We also observed high phenotypic correlations between sensitization to two aeroallergens (cockroach and dust mite: 0.83) and two food allergens (peanut and shellfish: 0.58), but only moderate correlations for the pairs between sensitization to a food and an aeroallergen (0.31-0.46). The shared genetic and environmental factors between paired sensitizations contribute to the observed correlations.

Conclusion:

We demonstrated that sensitization to common food and aeroallergens were influenced by both genetic and environmental factors. Moreover, we found that paired allergen sensitizations might share some common sets of genes and environmental factors. This study underscores the need to further delineate unique and/or pleiotropic genetic and environmental factors for allergen sensitization.

Background

The atopic diseases are generally diagnosed by performing skin prick tests (SPTs) to different aeroallergens. However, when this study results negative, it is possible to perform atopy patch test (APT). This technique has been introduced to evaluate sensitization to aeroallergens in patients with atopic eczema dermatitis syndrome. Nevertheless, its role in other allergic diseases has not been proved. Objective: Evaluate aeroallergens response using skin prick test (SPT) and atopy patch test (APT) in patients with allergic diseases.

Methods

Retrospective cohort study of individuals who performed SPT and APT as part of allergic diseases study. The study subjects were patch and skin prick tested to house dust mite (Dermatophagoides), trees, grass and fungi mix, cat and dog dander, among others. The tests were performed at the respiratory allergic disease center of Santa Maria Clinic in Santiago, Chile, between January 2010 and April 2011.

Results

Fifty-five patients were included, 18 (33%) males and 37 (67%) females, median age 6 years (range from 3 months to 62 years), with the following diagnosis: atopic dermatitis syndrome (60%), allergic rhinitis (58%), contact allergic dermatitis (16%), asthma (9%), recurrent bronchial obstructive syndrome (7%), allergic rhinoconjuctivitis (4%), chronic cough (4%), recurrent acute otitis media (2%) and recurrent laryngitis (2%). They underwent usual SPTs and APTs with multiple aeroallergens extracts. Of the 55 patients, 22 showed a positive SPT and 32 a positive APT; in 14 (25%) both, SPT and APT were positive. In 8 (15%) the SPT was positive and APT negative, while in 18 (33%) the SPT was negative, but the APT positive. Fifteen (27%) were negative to both tests.

Conclusions

Our results show that APT might be a useful diagnosis test in patients with allergic diseases and that its routine use can improve their diagnosis.

According to hygiene hypothesis, a lower exposure to infection is associated with increased prevalence of allergic diseases. This study aimed to investigate the association between atopy and Toxoplasma gondii (Tg) infection by analyzing the antibody and cytokine responses to house dust mite allergens and T. gondii antigens in Brazilian subjects. A total of 275 individuals were assessed and divided into atopics (n=129) and non-atopics (n=146) based on markers of allergy (positive skin prick test and ELISA-IgE to mite allergens) or Tg-seropositive (n=116) and Tg-seronegative (n=159) groups according to infection markers (positive ELISA-IgG to T. gondii). Tg-seropositive individuals presented lower allergenic sensitization (37%) to mite allergens than Tg-seronegative subjects (54%). A significant association was found between atopy and negative serology to T. gondii (OR: 2.0; 95% CI: 1.23–3.26; P<0.05). Proliferative responses and cytokine production after antigenic stimulation showed predominant synthesis of Th1-cytokines as IFN-γ in Tg-seropositive patients, whether atopics or non-atopics. Conversely, Th2-cytokines as IL-5 prevailed in atopics compared to non-atopics, regardless the seropositivity to T. gondii. Levels of IL-10, IL-13, IL-17, and TGF-β were not able to discriminate the groups. Hence, a negative association between atopy and infection by T. gondii was demonstrated for the first time in Brazilian subjects, focusing on the antibody and cytokine responses and indicating that the immunomodulation induced by the parasite may play a protective role in the development of allergic diseases.

Purpose of review

Asthma prevalence has markedly increased over the past 30 years. While atopy and exposure to environmental allergens is known to exacerbate asthma, recent literature supports a causal role of indoor allergens in disease development.

Recent findings

High risk birth cohorts continue to point to atopy as the main risk factor for developing asthma. Exposure to perennial allergens has also been linked to the development of asthma, though with less consistency. Intervention at the level of exposure mediation and allergic immune response is promising.

Summary

The current model of atopic asthma, the predominant phenotype, incorporates genetic and environmental factors in the development of disease. While genetic factors are less malleable, the environmental component lends itself to analysis and modification. For many, the development of asthma starts with allergen exposure leading to atopic sensitization and subsequent disease. Several studies support the progression from exposure to sensitization with the potential of extremely high levels of exposure leading to tolerance. Likewise, the progression from atopy to asthma is well documented, especially in genetically predisposed children. Recent intervention trials confirm these findings and begin to show promise for the prevention of asthma by interrupting the allergen exposure→allergen sensitization→atopic asthma pathway.

Background

Prevalence of obesity and atopy had been increased simultanoeuosly. The relationship between obesity, atopy, and total serum IgE had been estimated. The aim of this study is to find out the relationship between total serum Ig E, atopy, and obese children with or without family history of atopic disease.

Methods

This was a cross sectional study. There were 160 children aged 6 to 11 years which were divided into 4 groups: obese children with and without family history of atopic disease and normal weight children with and without family history of atopic disease. Atopic was defined by positive result of one of allergens skin prick test and ECLIA method were done for total serum IgE. Significancy for categorical data used Chi-Square test. Logistic regression model were used to examine the relationship between obesity, total serum IgE, and atopy.

Results

We measured the total serum IgE of 155 children. The number of obese and normal weight children with family history of atopic disease who had high level of total serum IgE were 30 and 25 respectively, whereas these children who had normal level of total serum IgE were 6 and 15 respectively [OR = 1.9 (95% CI 0.9-3.9)]. On the other hand, obese and normal weight children without family history of atopic disease who had high level of total serum IgE were 21 and 11 respectively, whereas these children who had normal level of total serum IgE were 18 and 29 respectively [OR = 1.7 (95% CI 1.1-2.7)]. The number of obese and normal weight children without family history of atopic disease who had atopy were 38 and 9 respectively, whereas these children who had non-atopy were 2 and 31 respectively [OR = 13.3 (95% CI 3.5-52)], but there was no relationship between atopy and obesity in group with family history of atopic disease (P = 0.314).

Conclusions

There were relationship between high level of total serum IgE and obesity in group with and without family history of atopic disease and also relationship between atopy and obesity in group without family history of atopic disease.

Allergic rhinitis is common among children and quite often represents a stage of the atopic march. Although sensitization to food and airborne allergens may appear in infancy and early childhood, symptoms of the disease are usually present after age 3. The aim of this study was to determine the most frequent food and indoor and outdoor respiratory allergens involved in allergic rhinitis in children in the region of Piraeus. The study was performed in the outpatient clinic of otolaryngologic allergy of a general hospital. Fifty children (ranged 6–14 ) with symptoms of allergic rhinitis and positive radioallergosorbent test (RAST) for IgE antibodies or skin prick tests were included in the study. Thirty six (72%) of the subjects of the study had intermittent allergic rhinitis. The most common aeroallergens determined were grass pollens and Parietaria, whereas egg and milk were the food allergens identified. The detection of indoor and outdoor allergens in the region of Piraeus, based on skin prick tests and RAST tests, showed high incidence of grasses and food allergens, which is similar to other Mediterranean countries.

Background

Asthma, allergic rhinitis (AR), and atopic dermatitis (AD) are the most prevalent allergic diseases and number of studies has shown an increase in prevalence of both all over the world in recent years. Although little about the prevalence of asthma, AR, and AD in Korean adults. And the incident sensitization to common allergens in the setting of sensitization to an occupational allergen has not been described. Our aim was to determine the prevalence of living and working place in adults. And also, determines the sensitization to common allergens in subjects with incident sensitization to a work-related allergen.

Methods

We performed questionnaire survey and allergy skin prick test with 27 common inhalant allergens among 294 subjects (response rate, 94.9%, n = 279) age 19 to 54 years in Seoul and forest service workers. One hundred thirty four subjects were forest service workers and 145 subjects were urban office workers.

Results

The mean age was 33.7 ± 7.6 years. There were 141 man and 138 women. A history of asthma was noted in 3.8% and a history of AR was noted in 28.7%. And a history of AD was noted 21.3%. The each group of sensitization to allergen were 40.3% (urban) and 60.0% (forest), (P = 0.002). The most common allergen was mites. The sensitization to birch allergen were more high in urban office workers (P = 0.01).

Conclusions

The prevalence of allergic rhinitis in urban areas was high. And urban officer workers were also high with sensitization rate compare to forest workers. The interesting results were the pollen sensitization rate in urban areas showed higher tendencies. More research will be needed in futures.

Background

Obesity and allergic diseases have increased dramatically in recent decades. While adiposity has been associated with asthma, associations with allergic sensitization have been inconsistent.

Objective

To examine the association of adiposity and lipid profiles with allergic sensitization.

Methods

This study included 1,187 rural Chinese twins (653 men) aged 18-39 years, with skin prick tests (SPT), anthropometric and DEXA-assessed adiposity measures, and lipid assessments. Allergic sensitization was defined as positive SPT to ≥1 allergen (9 foods and 5 aeroallergens tested). We applied gender-stratified generalized estimating equations to assess the association of adiposity and serum lipids with allergic sensitization, and structural equation models to estimate the genetic/environmental influences on any observed associations.

Results

Males had lower percent body fat (%BF) (13.9% vs. 28.8%) but higher rates of allergic sensitization (56.2% vs. 36.7%) than females. Males in the highest %BF quartile were 2.1 times more likely sensitized than the lowest quartile (95%CI 1.3-3.5, P-trend=0.003). In males, the risk of allergic sensitization increased with HDL<40 mg/dl (OR=4.0, 95%CI 1.8-9.2) and higher LDL quartiles (P-trend=0.007). This appeared to be partially explained by shared genetic factors between serum lipid levels and allergic sensitization. In females, lower HDL was associated with increased risk of allergic sensitization.

Conclusions

In this relatively lean Chinese population, higher %BF, lower HDL and higher LDL were associated with greater risk of allergic sensitization, most notable in males. The observed associations between adiposity, serum lipids and allergic sensitization in males appear to be partially explained by common genetic influences on these traits.

There is controversy about whether allergic disease has increased in recent decades. This study compared the prevalence of atopy, as shown by allergy skin prick testing among adults in 1988 (n = 74) with a similar study carried out in 1974 (n = 1359). Both study groups were drawn from the general population in south west London, but the 1988 sample specifically excluded people with rhinitis. The proportion of subjects with at least one positive reaction to a panel of three common allergens increased significantly from 23% in 1974 to 46% in 1988 (P less than 0.01). If allowance was made for the exclusion of rhinitis subjects from the 1988 sample, the current prevalence of atopy may be higher still. The increase in prevalence was significant in older subjects (aged 55-59 years) and women but not in other age groups or in men. This small study raises the possibility that atopy has increased in prevalence in the UK over recent decades and additional studies are needed to evaluate the validity of this hypothesis.

The degree to which aeroallergens are contributing to the global increase in pediatric allergic disease is incompletely understood. We review the evidence that links climate change to changes in aeroallergens such as pollen and outdoor mold concentrations and subsequently, aeroallergen association with pediatric allergic disease. We specifically explore the evidence on both the exacerbation and the development of allergic disease in children related to outdoor pollen and mold concentrations. Pediatric allergic diseases include atopic dermatitis or eczema, allergic rhinitis or hay fever, and some types of asthma in children, typically defined as less than 18 years of age. We discuss how the timing of aeroallergen exposure both in utero and in childhood could be associated with allergies. We conclude that the magnitude and type of health impacts due to climate change will depend on improved understanding of the relationship between climatic variables, multiple allergen factors, and allergic disease. Improved public health strategies such as adequate humidity control, optimum air filtration and ventilation, and improved anticipatory public health messaging will be critical to adaptation.

Background

Food-allergy is a substantial and evolving health issue. We evaluate the frequency of food sensitization by prick-to-prick and atopy patch test (APT) in allergic children in a tertiary pediatric care center.

Methods

Cross-sectional retrospective study of prick-to-prick and APT tests made in atopic children attending to the Pediatric Allergy and Clinical Immunology outpatient clinic aged 6 months to 19 years. Patients were stratified in 4 groups according to age (<1, 1–5, 6–10 and >11 years), and by atopy-related diagnosis (asthma, rhinitis, food allergy, atopic dermatitis and eosinophilic gastroenteropathy).

Results

Total of 170 prick-to-prick with fresh foods were made, 135 were positive with the next distribution: milk 28.8%, (95% CI, 21.3-36.3%), egg white 20.1% (95% CI, 13.5-26.8%), banana 19.4% (95% CI, 12.8-26%). Sensitization to milk was most common in children aged 1 to 5 years old with 26.9% (95% CI, 17.1-36.8%) compared with corn, nuts and peanuts P < 0.05. Sensitization to milk was the most frequent in the food allergy diagnosis group with 27.1% (95% CI,15.8-38.5%) compared with wheat, corn and peanuts P < 0.05.

A total of 140 APT tests were made, 105 were positive with the next distribution: soybeans 53.3% (95% CI,43.8-62.8%), peanut and chocolate both with 50.5% (95% CI,40.9-60,.0). This finding was sustained in patients with atopic dermatitis with soybean 55.6% (95% CI,36.8-74.3) compared to egg yolk. Sensitization to soybeans was most common in children aged 1 to 5 years old with 52.1% (95% CI,40.6-63.6) compared to rice and egg yolk P < 0.05. A different distribution was found for the 6 to 10 years old aged group: peanut 41.9% (95% CI,27.1-56.6) compared with egg yolk P < 0.05.

Conclusions

Milk is the most common food-allergen found by prick-to-prick in children independent of age or allergic diagnosis, with statistical significant difference, when compared to other food-allergens, in the group of food-allergy diagnosis and in the 1 to 5 years old age-group. Soybean is the most common food-allergen found in atopy patch test in the groups <1, 1 to 5 and >11 years old, independent of atopy related diagnosis, with statistical significant difference, when compared to other food-allergens in the group of atopic dermatitis and in the 1 to 5 years old age-group. For the 6 to 10 years old group peanut was the most common food-allergen found by APT, independent of atopy related diagnosis

Atopy is widely used as a discriminant in selection for employment involving exposure to allergenic substances. The validity of this has been tested in a population with a known burden of what is largely considered to be an IgE mediated disease, laboratory animal allergy. The findings suggest that atopy is insufficiently sensitive and specific for this purpose and that this is probably true for other occupational allergic diseases. The relation between different concepts of atopy--namely, atopy defined by family history, by personal history, and by skin prick tests with common allergens--has also been examined. The subpopulations identified by these criteria differed appreciably. Different concepts of atopy should not be used synonymously as they often are at present.

Background

The association between sensitizations and severity of allergic diseases is controversial.

Objective

This study was to investigate the association between severity of asthma and rhinitis and degree of specific allergic sensitization in allergic patients in China.

Method

A cross-sectional survey was performed in 6304 patients with asthma and/or rhinitis from 4 regions of China. Patients completed a standardized questionnaire documenting their respiratory and allergic symptoms, their impact on sleep, daily activities, school and work. They also underwent skin prick tests with 13 common aeroallergens. Among the recruited subjects, 2268 provided blood samples for serum measurement of specific IgE (sIgE) against 16 common aeroallergens.

Results

Significantly higher percentage of patients with moderate-severe intermittent rhinitis were sensitized to outdoor allergens while percentage of patients sensitized to indoor allergens was increased with increasing severity of asthma. Moderate-severe intermittent rhinitis was associated with the skin wheal size and the level of sIgE to Artemisia vulgaris and Ambrosia artemisifolia (p < 0.001). Moderate-severe asthma was associated with increasing wheal size and sIgE response to Dermatophagoides (D.) pteronyssinus and D. farinae (p < 0.001). Moderate-severe rhinitis and asthma were also associated with increase in number of positive skin prick test and sIgE.

Conclusions

Artemisia vulgaris and Ambrosia artemisifolia sensitizations are associated with the severity of intermittent rhinitis and D. pteronyssinus and D. farinae sensitizations are associated with increasing severity of asthma in China. Increase in number of allergens the patients are sensitized to may also increase the severity of rhinitis and asthma.

Background

The associations between sensitizations and severity of allergic diseases are controversial. This study was to investigate the association between severity of asthma and rhinitis and degree of specific allergic sensitivity in allergic patients in China.

Methods

A cross-sectional survey was performed in 6,304 patients with asthma and/or rhinitis from 4 regions of China. Patients completed a standardized questionnaire related to the respiratory and allergic symptoms, their impact on sleep, daily activities, school and work. They also underwent skin prick tests with 13 common aeroallergens. 2,268 of them were taken blood for serum specific IgE (sIgE) measurements for 16 common aeroallergens.

Results

Significantly higher percentage of patients with moderate-severe intermittent rhinitis were sensitized to outdoor allergens while percentage of patients sensitized to indoor allergens was increased with increasing severity of asthma. Moderate-severe intermittent rhinitis was related to skin wheal size and sIgE to Artemisia vulgaris and Ambrosia artemisifolia (P < 0.001). Moderate-severe asthma was associated with increasing in skin and sIgE response to Dermatophagoides (D.) pteronyssinus and D. farinae (P < 0.001). Moderate-severe rhinitis and asthma were also associated with increasing in number of skin and sIgE sensitized allergens.

Conclusions

Outdoor allergen sensitizations are significantly associated with severity of intermittent rhinitis and indoor allergen sensitizations are significantly associated with severity of asthma in patients in China. Number of allergen sensitization is also related to severity of rhinitis and asthma.

Background

Increased exposure to microbial products early in life may protect from development of atopic disorders in childhood. Few studies have examined the relationship of endotoxin exposure and pet ownership on atopy and wheezing during infancy.

Objective

Evaluate relationships among high endotoxin exposure, pet ownership, atopy, and wheezing in high-risk infants.

Methods

Infants (n = 532; mean age, 12.5 ± 0.8 months) with at least 1 parent with confirmed atopy were recruited. A complete medical history and skin prick testing to foods and aeroallergens were performed at age 1 year. House dust samples were analyzed for endotoxin.

Results

Prevalences of wheezing were not independently associated with dog or cat ownership or endotoxin levels. Percutaneous reactivity to at least 1 allergen was observed in 28.6% of infants. Univariate analyses showed significant associations of any wheezing, recurrent wheezing, and recurrent wheezing with an event with daycare attendance, number of siblings, respiratory infections, maternal smoking, and history of parental asthma. Logistic regression adjusting for the latter variables showed that recurrent wheezing (odds ratio, 0.4; 95% CI, 0.1–0.9) as well as 2 other wheeze outcomes were significantly reduced in homes with high endotoxin exposure in the presence of 2 or more dogs.

Conclusion

Pet ownership or endotoxin did not independently modify aeroallergen sensitization or wheezing during infancy. However, high endotoxin exposure in the presence of multiple dogs was associated with reduced wheezing in infants. Clinical implications: A home environment with many dogs and high levels of endotoxin may be conducive to reduced wheezing in infancy.

Background

Factors which determine the development of atopy and the observed rural-urban gradient in its prevalence are not fully understood. High body mass index (BMI) has been associated with asthma and potentially atopy in industrialized countries. In developing countries, the transition from rural to urban areas has been associated with lifestyle changes and an increased prevalence of high BMI; however, the effect of high BMI on atopy remains unknown in this population. We therefore investigated the association between high BMI and atopy among schoolchildren living in rural and urban areas of Ghana.

Methods

Data on skin prick testing, anthropometric, parasitological, demographic and lifestyle information for 1,482 schoolchildren aged 6-15 years was collected. Atopy was defined as sensitization to at least one tested allergen whilst the Centres for Disease Control and Prevention (CDC, Atlanta) growth reference charts were used in defining high BMI as BMI ≥ the 85th percentile. Logistic regression was performed to investigate the association between high BMI and atopy whilst adjusting for potential confounding factors.

Results

The following prevalences were observed for high BMI [Rural: 16%, Urban: 10.8%, p < 0.001] and atopy [Rural: 25.1%, Urban: 17.8%, p < 0.001]. High BMI was not associated with atopy; but an inverse association was observed between underweight and atopy [OR: 0.57, 95% CI: 0.33-0.99]. Significant associations were also observed with male sex [Rural: OR: 1.49, 95% CI: 1.06-2.08; Urban: OR: 1.90, 95% CI: 1.30-2.79], and in the urban site with older age [OR: 1.76, 95% CI: 1.00-3.07], family history of asthma [OR: 1.58, 95% CI: 1.01-2.47] and occupational status of parent [OR: 0.33, 95% CI: 0.12-0.93]; whilst co-infection with intestinal parasites [OR: 2.47, 95% CI: 1.01-6.04] was associated with atopy in the rural site. After multivariate adjustment, male sex, older age and family history of asthma remained significant.

Conclusions

In Ghanaian schoolchildren, high BMI was not associated with atopy. Further studies are warranted to clarify the relationship between body weight and atopy in children subjected to rapid life-style changes associated with urbanization of their environments.

The aim was to test the hypothesis that atopy increases the occurrence of chronic bronchitis. Relations between atopy, smoking, and chronic bronchitis were studied in farmers. The data were from two successive postal surveys and a skin prick tested subsample. The cross-sectional study consisted of 9017 farmers. Those 6899 farmers who did not have chronic bronchitis at the beginning and who continued farming were followed for three years. A sample of 150 farmers was skin-tested with 36 allergens. The prevalence of chronic bronchitis (rate per 1000), standardised for age and sex, was 41 in non-atopic non-smokers, 101 in atopic non-smokers, 106 in non-atopic smokers, and 257 in atopic smokers (effect of atopy: p less than 0.001; effect of smoking: p less than 0.001). The standardised incidence rates of chronic bronchitis (per 1000 farming years) were 14, 34, 36, and 50, respectively (atopy: p less than 0.001; smoking p less than 0.001). The relative risk of chronic bronchitis, calculated from the incidence data adjusting for the effects of age, sex, smoking or atopy by logistic regression analysis was 2.2 for atopy (95% confidence interval 1.8-2.7) and 2.3 for smoking (1.8-2.9). Only 20 farmers had chronic bronchitis in the skin-tested subjects; the results were consistent with the findings in the surveys but did not reach statistical significance for atopy. In conclusion, atopy and smoking have independent and additive effects on the occurrence of chronic bronchitis at least in dusty farming work.

Introduction

Polymorphisms within innate immunity genes are associated with allergic phenotypes but results are variable. These associations were not analyzed with respect to allergen exposure. We investigated associations of TLR and CD14 polymorphisms with allergy phenotypes in the context of house dust mite (HDM) exposure.

Material and methods

Children, aged 12-16 years (n=326), were recruited from downtown and rural locations and assessed by allergist. Skin prick tests, total and HDM-specific sIgE measurements were done. HDM allergen concentrations in dust were measured. Genetic polymorphisms were identified using restriction fragment length polymorphism (RFLP).

Results

Allergic rhinitis, asthma and atopy were more prevalent in urban area. Although HDM allergen concentrations were higher in rural households, sIgE were present more frequently in urban children. In the whole population no association was found between HDM exposure and sensitization. In children with CD14/−159CC, CD14/−159TT and TLR9/2848GA genotypes increased exposure to HDM was associated with reduced incidence of allergic rhinitis. Significant associations of increased HDM exposure with reduced incidence of atopy were found for the whole population and subjects with CD14/−159CC, CD14/−1359GT, TLR4/896AA and TLR9/2848GA genotypes. Among children with CD14/−159CC and CD14/−1359GG significant positive correlation between HDM allergen concentrations in household and sensitization to HDM was observed. In contrast, protective effect of high HDM allergen exposure against specific sensitization was seen in subjects with TLR4/896 AG.

Conclusions

Development of specific sensitization and allergy may be associated with innate immune response genes polymorphisms and is modified by allergen exposure.

Background

The prevalence of sensitization to allergens and symptoms of allergic disease differ with regard to age, but the relationship is poorly understood. This study aimed to investigate the patterns of allergen sensitization and allergic symptoms with regard to age in early childhood.

Methods

A cross-sectional study was conducted on 629 children. Current allergic symptoms were assessed using the Korean-language ISAAC questionnaires adapted for preschool-aged children. The sensitization to five aero- and 3 food- allergens was evaluated by skin prick test.

Results

The prevalence of current asthma decreased (20.5%/8.2%), current rhinitis increased (36.1%/56.1%) with increasing age from 3 to 6 years, while no change in the prevalence of current eczema (16.9%/15.3%). Similarly, as age increased, sensitization rates to inhalant allergens increased (21%/33%), those to food allergens decreased (10%/2%). The prevalence of polysensitized children increased (8%/22%), monosensitized children decreased (18%/11%) with age, but atopic state did not change with age (27%/33%). The agreement rate between sensitization to dust mite and atopic state increased with age, showing a rate of 93% at 6 years (P = 0.05). The presence of atopic dermatitis in the first 2 years of life (aOR = 4.1, 2.2–7.6, P < 0.001) and polysensitization (aOR = 3.0, 1.4–5.0, P < 0.005) were significant risk factors for current rhinoconjunctivitis. In contrast, monosensitization was a risk factor for current asthma (aOR = 2.1, 1.1–4.1, P < 0.024) and current eczema (aOR = 2.1, 1.0–4.3, P < 0.042).

Conclusions

These data showed that the type and numbers of sensitization and allergic symptoms changed with age in early childhood. Polysensitization may play an important role in allergic march.

Background

Allergic diseases affect a great proportion of seniors. Our objective was to determine the prevalences of allergen sensitization in this age group.

Methods

Retrolective study was performed during 3 years follow-up at Hospital School in Guadalajara city, Mexico. The allergen sensitization with a common allergen panel by a prick test was evaluated in seniors of first consultation in an Allergology Service.

Results

We included 60 subjects, with an average of 67.7 years old; 83.3were women. Diagnosis of allergic rhinitis was present in 60%, allergic rhinitis plus asthma in 30%, and asthma alone in 10%. Non atopic comorbidities were present in 56.7% of the cases. Median of serum IgE was 124.95 UI/mL, whereas for positive prick test was 4 (minimum-maximum, 1–21); 13.3% were sensitized to just 1 aeroallergen, and 55% were to more than 3 aeroallergens. Sensitization to pollens was predominant, even more to tree pollens. One by one, house-dust mite, Fraxinus sp and Amaranthus palmeri were the most common found. To have diabetes was associated to a minor positive prick test (P = 0.021).

Conclusions

It's recommendable to identify the allergen sensitization in seniors with allegic disease symptoms, as part of their evaluation. The most common sensitizing allergens are similar for other age groups proceeding from the same area. It's recommendable to search for more findings possibly associated between diabetes and number of positive prick tests.

Background

Asthma and allergy are highly prevalent in industrialised countries. Longitudinal and cross-sectional studies have identified a number of potential risk factors for these conditions, including genetic and environmental factors, with significant gene-environment relationships. Birth cohort studies have been proposed as an important tool to explore these risk factors, particularly exposures in early life that are associated with later disease or protection from disease. This paper describes the establishment of a birth cohort in New Zealand.

Methods

A birth cohort was established in 1996 in Christchurch and Wellington and infants recruited between 1997–2001. Expectant mothers were recruited by midwives. Children and mothers have undergone assessment by serial questionnaires, environmental assessment including mould and allergen exposure, skin-prick testing, and at age six years are undergoing full assessment for the presence of asthma, atopy and allergic disease, including genetic assessment.

Results

A total of 1105 children have been recruited, and the retention rate at fifteen months was 91.4%. 15.2% of the children at recruitment have been identified as Maori. A positive family history of asthma, eczema or hay fever has been reported in 84% of children. All children have now been assessed at fifteen months and 685 children from the cohort have reached age six years and have completed the six year assessment.

Conclusion

The cohort is fully assembled, and assessment of children is well advanced, with good retention rates. The study is well placed to address many current hypotheses about the risk factors for allergic disease and asthma.

Background

Children often develop allergies that may or not persist into adulthood. Although the different allergic symptoms over time have been well documented, the underlying pattern of sensitization to various proteins and subsequent allergy development is unexplored.

The aim was to study the sensitization pattern to allergen components over time from infancy to adulthood in a group of infants with heredity for allergic diseases.

Methods

IgE profiles were monitored in a group of 67 children from 6 months to 18 years using a microarray chip (ImmunoCAP® ISAC) containing 103 allergen components derived from 47 allergen sources. The chip IgE profile was compared with clinical history, skin prick test results and diagnoses (atopic dermatitis, asthma and allergic rhinoconjunctivitis) at each time point for each child.

Results

IgE profiles were unique for each child and showed broad agreement with the results of skin prick tests and doctors’ diagnoses. In addition, close examination of the IgE profiles often revealed early indication of subsequent allergies. IgE profiles also facilitated the examination of cross-reactivity contra co-sensitization, thereby greatly enhancing the possibility for managing patients.

Conclusion

This explorative description indicates that sensitization pattern to allergen components differs over time as well as among allergic individuals when examined with microarray technology.

Background

Most childhood asthma in poor populations in Latin America is not associated with aeroallergen sensitization, an observation that could be explained by the attenuation of atopy by chronic helminth infections or effects of age.

Objective

To explore the effects of geohelminth infections and age on atopy, wheeze, and the association between atopy and wheeze.

Methods

A case-control study was done in 376 subjects (149 cases and 227 controls) aged 7–19 years living in rural communities in Ecuador. Wheeze cases, identified from a large cross-sectional survey, had recent wheeze and controls were a random sample of those without wheeze. Atopy was measured by the presence of allergen-specific IgE (asIgE) and skin prick test (SPT) responses to house dust mite and cockroach. Geohelminth infections were measured in stools and anti-Ascaris IgE in plasma.

Results

The fraction of recent wheeze attributable to anti-Ascaris IgE was 45.9%, while those for SPT and asIgE were 10.0% and 10.5% respectively. The association between atopy and wheeze was greater in adolescents than children. Although Anti-Ascaris IgE was strongly associated with wheeze (adj. OR 2.24 (95% CI 1.33–3.78, P = 0.003) and with asIgE (adj. OR 5.34, 95% CI 2.49–11.45, P < 0.001), the association with wheeze was independent of asIgE. There was some evidence that the association between atopy and wheeze was greater in uninfected subjects compared with those with active geohelminth infections.

Conclusions and clinical relevance

Atopy to house dust mite and cockroach explained few wheeze cases in our study population, while the presence of anti-Ascaris IgE was an important risk factor. Our data provided only limited evidence that active geohelminth infections attenuated the association between atopy and wheeze in endemic areas or that age modified this association. The role of allergic sensitization to Ascaris in the development of wheeze, independent of atopy, requires further investigation.

OBJECTIVE: To determine the prevalence of sensitisation to peanuts and tree nuts in all children born during one year in one geographical area. DESIGN: Birth cohort study with structured review at ages 1, 2, and 4 years. SETTING: All children born on the Isle of Wight between January 1989 and February 1990. SUBJECTS: Of 1456 children originally included, 1218 were reviewed at age 4 years. Of these, 1981 had skin prick tests. MAIN OUTCOME MEASURES: Positive skin test results, clinical atopic disease, and risk factors for the development of atopy. RESULTS: 15 of 1218 (1.2%) children were sensitised to peanuts or tree nuts (13 to peanuts). Six had had allergic reactions to peanuts (0.5% of the population), one to hazelnuts, and one to cashew nuts; three had had anaphylactic reactions. Seven children had positive skin test results or detectable IgE to peanuts without clinical symptoms. Two children who reacted to peanut in infancy had lost their sensitivity by 4 years. Family history of atopy, allergy to egg (odds ratio 9.9, 95% confidence interval 2.1 to 47.9, and eczema (7.3, 2.1 to 26.1) were important predictors for peanut allergy. CONCLUSIONS: IgE mediated allergy to peanuts is common in early childhood. In many the allergy persists but a minority may develop tolerance.