The association of allergic symptoms with sensitization to inhalant allergens in childhood

Although it is generally agreed that sensitization is an important risk factor for allergic diseases, the extent to which sensitization accounts for allergic symptoms in children is controversial. As part of the Aalst Allergy Study, this cross‐sectional study investigated the prevalence of allergic symptoms and their association with sensitization in an unselected population of Flemish children aged 3.4–14.8 yr. Skin prick testing with the most common aeroallergens was performed and allergic symptoms were documented by a parental questionnaire. In the children older than 6 yr, a significant association of current wheezing, current dyspnea, airway hyperreactivity, rhinoconjunctivitis, and current eczema with sensitization was found, while in the pre‐school children these associations were less pronounced. The association with sensitization was strongest for rhinoconjunctivitis and current respiratory symptoms – the association was less striking for children with current eczema. The impact of a positive family history of allergy on the association with sensitization was more important for eczema than for the other analyzed allergic symptoms. Persistent and late‐onset wheezers were significantly more likely than non‐wheezers and transient early wheezers to be associated with sensitization and a personal history of rhinoconjunctivitis. Late‐onset wheezing was associated with a positive family history of allergy, while transient early wheezing was associated with day‐care attendance. An association with eczema was found for all three childhood wheezing phenotypes. The association of allergic symptoms with sensitization is significant in the older but less pronounced in pre‐school children and is more pronounced for current allergic symptoms. Diagnosis and disease definition of allergy symptoms remains difficult at pre‐school age. The influence of a positive family history of allergy on the association of the respective allergic symptoms with sensitization was most important for eczema. Our data confirm the atopic characteristics of the different wheeze phenotypes.     

The influence of age and gender on sensitization to aero-allergens

Boys run a higher risk for atopy than girls but this gender difference is less pronounced in adulthood. The underlying mechanisms and the exact timing of this decrease in male/female ratio remain unclear. The aim of this study was to evaluate the effect of age and gender on sensitization in schoolchildren. A cross-sectional study was performed in an unbiased community population of 2021 Belgian schoolchildren, aged 3.4-14.8 yr. The overall sensitization and the sensitization for mites, mixed grass pollens and tree pollens increased significantly with increasing age. Male sex was strongly associated with sensitization (OR(adj) 2.0, 98% CI 1.6-2.4). Male predominance was more obvious in children under the age of 8 yr. After the age of 8 male predominance persisted, but a significant increase in sensitized females occurred. Our data demonstrate a significant increase in prevalence of sensitization with age and a significant decrease in male/female ratio of sensitization after the age of 8 yr, although a male predominance persists. These data are the first published data ever that document this change in male/female ratio in sensitization at this age.     

Messages from the Aalst Allergy Study

Background  The prevalence of sensitization and allergic disease has increased significantly worldwide. The aim of the “Aalst Allergy Study” was to document prevalences of sensitization and allergic symptoms, and to evaluate the effect of personal and environmental influences on these prevalences in an unbiased Belgian pediatric population. Methods  A cross-sectional study was performed in an unbiased population of 2021 Belgian schoolchildren (3.4–14.8 years). Skin prick testing with the most common aeroallergens was performed. Allergic symptoms as well as potential risk factors for sensitization and allergic disease were documented by a parental questionnaire. Results  The prevalence of sensitization to the most common aeroallergens and the prevalence of allergic diseases (eczema, asthma and rhinoconjunctivitis) were in line with the data in the literature. The association of current allergic symptoms with sensitization was only significant in the children aged ≥6 years. Age, gender, body mass index, bedroom environment and exposure to pets were the factors significantly associated with sensitization and allergic symptoms. Conclusions  Our study corroborates the reported prevalences of sensitization and allergic diseases. Moreover the study illustrates the complexity of the search for factors involved in the process of sensitization and allergic disease. The impact of different potential causative factors is not only influenced by mutual interactions of these factors, but also by the existence of distinct subtypes of disease.     

Sensitization to common indoor allergens and its association with allergic diseases in Thai female high-school students

Allergic sensitization is generally agreed to be an important risk factor for allergic diseases. It has been demonstrated in most of the children attending allergy clinics in Thailand but has never been studied in Thai general populations. The objectives were (i) to describe the prevalence of sensitization to common indoor allergens in Thai female-high-school students and (ii) to evaluate the association of allergic sensitization to allergic diseases in these students. cross-sectional analytic study was designed. Seven hundred and six schoolgirls were enrolled during May-June 2002. Written ISAAC questionnaires were completed by the students and skin prick tests were performed in 344 (48.7%) students with a battery of seven common allergens including Dermatophagoides pteronyssinus, Dermatophagoides farinae, American cockroach, Cat, Cladosporium, Penicillium, and Aspergillus. Positive test was defined as a mean wheal diameter of at least 3 mm at the 15 min reading. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were obtained from multiple regression analysis for the independent effect of sensitization to each allergen on allergic diseases. A total of 154 (44.8%) students had evidence of allergic sensitization on skin prick tests. The prevalence rates of sensitization to various groups of allergens were as follows; mites 43.0%, cockroach 12.8%, cat 4.1%, and molds 1.2%. The independent effect of allergic sensitization on allergic diseases was observed only in mite sensitization on nose problem (OR = 1.73, CI = 1.07-2.78 for nose problem ever and OR = 1.85, CI = 1.13-3.02 for nose problem in 12 months). The risk of nose problem was also increased with the number of positive reactions. CONCLUSION: We found that sensitization to the four common allergen groups were weakly associated with the presence of allergic diseases in Thai schoolgirls. This confirms the observation that the development of allergic diseases is not solely attributable to allergic sensitization.     

Parental smoking and allergic sensitization in offspring defined by skin prick testing

Investigations of parental smoking during childhood and allergic sensitization have produced contradictory results, but this may be because of variations in the definition of allergy and other influences. We investigated associations of parental smoking with an objective measure of allergy, skin prick testing (SPT), and considered associations with maternal and paternal smoking, independently of each other. A stratified random sample, aged 22-74 yr, of 720 Swedish FinEsS-study members were skin prick tested for 15 allergens. Subjects with at least one positive SPT were defined as atopic. Data on childhood exposures, including parental smoking, were collected by structured interview. Logistic regression used atopy as the dependent variable. After adjustment, paternal smoking was statistically significantly associated with an increased risk and maternal smoking a non-statistically significant decreased risk in offspring, with odds ratios (and 95% confidence intervals) of 1.48 (1.04-2.10) and 0.73 (0.48-1.12), respectively. Analysis of families with a non-smoking mother produced an odds ratio for paternal smoking of 1.61 (1.09-2.37). The negative association between maternal smoking and atopy may not operate through passive smoke exposure and could conceal a significant increased risk associated with passive exposure to tobacco smoke in childhood.     

Asthma and atopy in schoolchildren in a defined population

We investigated the frequency of allergic disorders, the pattern of allergen sensitization and serum total IgE concentration in a population-based sample of schoolchildren screened on the basis of respiratory symptoms ( A = 244). The children were classified on clinical grounds into three groups, asthma ( N = 43), other symptoms from lower airways (OSLA; N = 34) and control children ( N = 167). The frequency of allergic disorders (allergic rhinitis, conjunctivitis or dermatitis) differed significantly between children with asthma (81%), children with OSLA (62%) and in control children (48%) ( p < 0.001). The presence of at least one positive skin prick test result was equally common in children with asthma or OSLA (77%), but lower in control children (40%) ( p < 0.001). Serum total IgE concentrations did not differ between the three groups. Two conclusions can be drawn: (i) there is a strong association between clinical allergy, skin reactivity and asthma in school age children, and (ii) a similar association is present between allergy and asthma-like conditions.     

Urban living as a risk factor for atopic sensitization in Swedish schoolchildren

The prevalence of atopic sensitization was compared among all pupils in three urban school classes (median age 10, 12 and 14 years, respectively) and three corresponding classes in the adjacent rural district (642 pupils in all). A written questionnaire, oral interview and skin prick testing against 7 allergens were used, with skin tests performed on 93.4 % of the urban, and 92.0 % of the rural pupils. Contact with domestic animals was much more common in the rural area. Urban living was a risk factor for at least one positive skin test to pollen or animal dander, with odds ratio (OR) 1.83 and confidence interval (CI) 1.26–2.67. This was even more pronounced for children with both positive skin test and allergic symptoms (OR 2.13; CI 1.38–3.28). An increased prevalence of positive skin prick tests in the urban area compared with the rural environment was also found for 3 individual allergens, i.e. birch pollen (OR 1.78), timothy pollen (OR 1.87) and cat dander (OR 2.29). The relative risk for positive skin test in the urban area was further increased when standardized for allergic heredity, type of dwelling, daily exposure to tobacco smoke and dampness or abnormal smell in the home. This study suggests that various adjuvant factors increase the risk of sensitization in urban environments, particularly among children with a positive family history of allergy     

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??Objective To understand the trend of inhaled allergen positive rate among 0-12-year-old children from 2006 to 2013 in Chongqing Children’s Hospital??and to provide evidence for preventing allergic rhinitis in children. Methods??All cases were collected from Otorhinolaryngological Department of the Children’s Hospital of Chongqing Medical University from 1st January??2006 to 29th October??2013. Totally 10983 children with allergic rhinitis aged 0-12 years old in Chongqing urban districts were enrolled. All the patients underwent skin prick test??SPT?? with 13 standardized common inhalant allergens. Then the children were divided into the infants group??aged??3 years????preschool children??3 years≤aged??7 years?? and school-age children??7 years≤aged??12 years?? according to age. The trend of inhaled allergen positive rate over 8 years was observed. Results From 2006 to 2013??the SPT positive rate increased sharply??then tended to be stable??and then decreased slowly??Curve Estimation??R 2??0.836??adjustment R 2??0.770. ANOVA test??F??12.727??P??0.011??. It may be related to meteorological factors. With the growth of age??the positive rates of Dermatophagoides pteronyssinus??Dermatophagus farinae??Blomia tropicalis??Cockroaches??cat fur??dog fur and mugwort increased??which were 121.200??123.060??103.237??104.784??17.042??8.515 and 11.256??respectively????P was 0.000??0.000??0.000??0.000??0.000??0.014 and 0.004??respectively??. Conclusion ??Meteorological factors and age may have effects on allergic rhinitis??AR?? in children??with the growth of age??the positive rates of inhaled allergens have tendency variation.     

The association between early sensitization patterns and subsequent allergic disease. The DARC birth cohort study

Prevention of allergic diseases depends on early identification of clinical markers preceding such disorders. This study describes the natural course of sensitization as measured by skin prick test (SPT) and specific immunoglobulin E (S‐IgE) and analyses the association between early sensitization patterns and subsequent allergic disease at 6 yr of age. In an ongoing population‐based birth cohort study of 562 children, follow‐up visits were performed at 0, 3, 6, 9, 12, 18, 36, and 72 months. Visits included an interview, physical examination, SPTs, and S‐IgE measurements for 12 food and inhalant allergens. The frequency of S‐IgE sensitization to ≥1 inhalant allergen was constant from 0 to 6 months (9–10%), decreased at 12–18 months before increasing from 36 months onwards. S‐IgE sensitization to at least one food allergen remained constant from 0 to 6 yr. SPT sensitization to food and inhalant allergens appeared from 3 and 12 months, respectively. Early food sensitization (S‐IgE) between 3 and 18 months was found to be significantly (p < 0.05) associated with atopic dermatitis (OR: 4.0 [1.6–9.9]) and asthma (OR 4.0 [1.1–12.5]) at the age of 6 yr. Children with atopic dermatitis, asthma, or rhinoconjunctivitis, and sensitization at 6 yr, were sensitized to food allergens to a large extent (53%, 42%, and 47%, respectively) already at 6 months. Early inhalant sensitization (S‐IgE) did not increase the risk of later allergic disease. Early atopic dermatitis (0–18 months) was also highly associated with subsequent allergic disease. Children with early food sensitization and/or atopic dermatitis would be a proper target group for future interventional studies.     

Association of body mass index and season with histamine skin reactivity in Chinese children with allergic rhinitis

Background

To investigate the association between histamine skin reactivity and body mass index (BMI) and other clinical factors, 526 children (3–6 years old) who underwent a skin-prick test (SPT) to diagnose allergic rhinitis were enrolled.

气道过敏性疾病患儿气传过敏原致敏分布特征及临床意义

目的:了解气道过敏性疾病患儿气传过敏原致敏分布特征及临床意义。方法:收集北京儿童医院2019年1月至12月诊断为气道过敏性疾病并进行气传过敏原皮肤点刺试验(skin prick test,SPT)的2557例患儿资料进行回顾性分析。按年龄分为≤5岁组、6~11岁组、≥12岁组;按疾病分为过敏性鼻炎组、哮喘组、过敏性鼻炎...     

具有喘息症状或过敏性疾病的年幼儿皮肤点刺试验结果分析

目的：通过分析0~5岁儿童变应原皮肤点刺试验结果,了解具有喘息症状的可疑哮喘及过敏性疾病症状的患儿对吸入变应原过敏反应的特点,为儿童哮喘及过敏性疾病的早期诊断提供依据。方法：选择2010年9月1日至12月31日长沙市某社区0~5岁具有喘息症状或过敏性疾病症状的患儿共102例为变应原筛查组;对照组选择同年龄组无喘息及过敏性疾病史的儿童94例。两组均进行变应原皮肤点刺试验。结果：变应原筛查组皮肤点刺试验阳性率61.8%（63/102）明显高于对照组的9.6%（9/94）,差异有统计学意义（P<0.05）;反复喘息合并过敏性鼻炎者的皮肤点刺试验阳性率明显高于单纯喘息组（P<0.05）;喘息次数与皮肤点刺试验阳性率呈正相关（r=0.91,P<0.05）;对螨虫的皮肤点刺试验阳性率（24.2%）明显高于其他过敏原（3.5%）,差异有统计学意义（P<0.05）;粉尘螨的皮肤点刺阳性率（50.0%）明显高于屋尘螨（14.7%）,差异有统计学意义（P<0.05）。结论：早期儿童喘息可能是发生过敏性哮喘的重要因素;变应原皮肤点刺试验是诊断过敏性疾病的重要依据,并有助于评估喘息患儿对吸入性变应原的过敏反应特点。     

Influence of MMR-vaccinations and diseases on atopic sensitization and allergic symptoms in Swiss schoolchildren

The prevalence of asthma and allergic disease has increased in many countries. It has been proposed that vaccinations may contribute to the development of allergic disease by reducing clinical infections in infancy or through the direct IgE-inducing effects of the vaccines. Evidence for a potential role of immunizations in the development of allergic disease is scarce. Therefore the objective was to study the associations between vaccinations against measles, mumps and rubella (MMR), natural infections of these diseases and atopic sensitization to indoor and outdoor allergens and allergic symptoms in schoolchildren. The cross-sectional study including 1537 8(th) grade school children aged 13-15 years living in 10 communities across Switzerland was organized in the framework of an environmental health surveillance program within the School Health Services (Swiss Surveillance Program of Childhood Asthma and Allergies with respect to Air Pollution and Climate, SCARPOL). Main outcome measures were asthma and sneezing during pollen season assessed by parental questionnaires and atopic sensitization determined by IgE concentrations to various allergens. It was found that parents' reported history of measles or mumps was associated with a stronger immune response than two or more vaccinations against the respective infection (measles: geometric mean IgG titers (GMT) lU/ml (95% Cl) 2.8 (2.0-3.9) vs. 1.2 (1.0-1.4), mumps: GMT PE/ml (95% Cl) 16.3 (13.9-19.1) vs. 8.5 (6.1-11.7). With respect to atopic sensitization similar associations for exposure by natural MMR-infections or MMR-vaccinations were found: measles: OR (95% Cl) 1.02 (0.53-1.96) vs. 1.22 (0.69-2.16), mumps: 0.59 (0.38-0.93) vs. 0.79 (0.49-1.27), rubella: 0.93 (0.61-1.43) vs. 0.95 (0.66-1.37), respectively. Inverse relationships were found between the risk of asthma and a positive disease history or vaccination of measles 0.36 (0.14-0.91) vs. 0.45 (0.21-0.98) or a positive serum titer against measles 0.65 (0.35-1.20). From the present study can be concluded that exposure by MMR-vaccinations or natural MMR-infections in childhood does not increase the risk of sensitization to common allergens as well as to allergic respiratory diseases. MMR-vaccinations or natural MMR-infections are therefore an unlikely factor contributing to the increase in atopic disease in developed countries.     

Increase in atopic sensitization rate among Dutch children with symptoms of allergic disease between 1994 and 2014

Background

The prevalence of symptoms of allergic diseases has increased significantly during the last decades. However, studies into time trends of atopic sensitization among children are limited and have focused on aeroallergen sensitization. We aimed to investigate time trends in the prevalence and degree of atopic sensitization to inhalant and food allergens among children (0‐17 years) with symptoms of allergic disease.

Methods

Sensitization data of all children tested in our clinical laboratory during 1994‐2014 were analyzed. Sensitization was detected using the ImmunoCAP system and defined as a specific IgE level of ≥0.35 kU/L. Trends in sensitization rates to 5 food and 5 aeroallergens for different age categories were investigated with logistic regression, adjusted for age and sex.

Results

Sensitization data of 18 199 children were analyzed. Between 1994 and 2014, a steady and statistically significant increase in overall sensitization rate was found (from 40.5% in 1994 to 48.9% in 2014, adjusted odds ratio [aOR] 1.01 per year, 95% confidence interval [CI] 1.00 to 1.01, P = .003). This increase in sensitization rate was mainly explained by increasing aeroallergen sensitization among 4‐ to 11‐year‐old children (aOR 1.02, 95% CI 1.01 to 1.02, P < .001). We found no increase in sensitization rates to food and aeroallergens in other age categories. The degree of sensitization did not change significantly during the study period (all tests P > .15).

Conclusion

We observed a statistically significant increase in sensitization rate between 1994 and 2014 among children with symptoms of allergic disease. This was mainly explained by increasing aeroallergen sensitization among 4‐ to 11‐year‐olds.     

Specific fungal exposures, allergic sensitization, and rhinitis in infants

Indoor air quality has become increasingly important as we live in a society where the majority of our time is spent indoors. Specific attention has been drawn to airborne fungal spores as a factor affecting indoor air quality. This study targeted shortcomings of other studies by utilizing long-term air sampling and total fungal spore enumeration to determine associations between health outcomes and fungal spore concentrations. Infants (n = 144) were clinically evaluated and had skin prick tests (SPT) for 17 allergens. Airborne fungal spores were collected using a Button Personal Inhalable Sampler (SKC Inc.) for 48 h at a flow rate of 4 l/min. Sampling was conducted in the spring (March-May) or fall (August-October) in 2003-2004. Fungal spores were analyzed using microscopy-based total counting and identified to the genus/group level. Total spore and individual genus concentrations were analyzed for associations with rhinitis and positive SPT results. Overall, concentrations varied widely, between <2 and 2294 spores/m(3). While no relationship was observed between SPT(+) and total fungal counts, several significant associations were found when analysis was conducted on the various fungal genera and health outcomes. Positive associations were obtained between: Basidiospores and rhinitis (p < 0.01), Penicillium/Aspergillus and SPT(+) to any allergen (p < 0.01), and Alternaria and SPT(+) to any allergen (p < 0.01). Inverse associations were found between: Cladosporium and SPT(+) to any allergen (p < 0.05), and Cladosporium and SPT(+) to aeroallergens (p < 0.05). This study indicates that health outcome may vary by fungal genera; some fungal types may have sensitizing effects while others may have a beneficial role.