Comparison of wheat and rye flour solutions for skin prick testing: a multi‐centre study (Stad 1)

Background Skin prick testing (SPT) is the basic method for diagnosing IgE‐mediated allergies. However, skin reactivity is related to the quality of allergen extracts, which are often poorly defined for occupational allergens. Objective To compare wheat and rye flour SPT solutions from different producers. Materials and methods Standardized SPTs were performed in seven allergy centres with wheat and rye flour solutions from four producers in 125 symptomatic bakers. Optimal cut‐off levels for weal sizes were assessed with the Youden Index. Comparisons between SPT results of different solutions were made with flour‐specific IgE (sIgE) as the gold standard. Sensitivities, specificities, positive and negative predictive values, and test efficiencies were calculated and compared with McNemar and χ²‐tests. The influence of the choice of the gold standard (sIgE or challenge) test was examined for 95 subjects. Additionally, SPT solutions were analysed for protein and antigen content. Results The optimal cut‐off level for all SPT solutions was a weal size of 1.5 mm. While differences between wheat and rye flours were small, differences between producers were important. Variability of sensitivities (0.31–0.96), negative predictive values (0.42–0.91), and test efficiencies (0.54–0.90) were higher than variations of specificities (0.74–1.00) and positive predictive values (0.88–1.00). Similar results were obtained when using challenge test results as the gold standard. Variability could be explained by the different antigen contents of the SPT solutions. Conclusion There is a wide variability of SPT solutions for wheat and rye flour from different producers, mainly with respect to sensitivities, negative predictive values, and test efficiencies. Improvement and standardization of SPT solutions used for the diagnosis of baker's asthma are highly recommended.     

呼和浩特市720例变应性疾病变应原调查分析

目的:调查呼和浩特市地区变应性疾病患者常见变应原的分布情况。方法:以720例变应性疾病的患者为研究对象,进行11种吸入性变应原皮肤点刺试验,测定致敏变应原。结果:720例变应性疾病患者中577例(80.1%)变应原测试有阳性反应。577例阳性病例中艾蒿阳性率最高,315例(54.6%),其次是螨虫254例(44.0%)。结论:艾蒿、螨虫是呼和浩特市地区变应性疾病的最常见变应原。     

Concurrent cereal allergy in children with cow''s milk allergy manifested with atopic dermatitis

BACKGROUND: There is increasing consensus about the significance of food allergens in the pathogenesis of atopic dermatitis (AD) in infancy and childhood, with cow's milk and egg accounting for most of the reactions. Previous studies have indicated that multiple food sensitization, such as cereals, is very common in patients with cow's milk allergy (CMA). Evidence is lacking, however, as to its clinical relevance. OBJECTIVE: The purpose of this study was to determine the concurrent occurrence of cereal allergy among children with challenge-proven CMA who have residual symptoms, such as AD and/or gastrointestinal symptoms, during cow's milk elimination diet. Further, we sought to evaluate the utility of patch testing in prescreening foods other than cow's milk behind allergic symptoms in children. METHODS: The study population comprised 90 children, aged from 2.5 to 36 months (mean 1.1 years), with challenge-proven CMA. As a result of residual symptoms during meticulous cow's milk elimination diet (AD: n=80, and gastrointestinal: n=10), the children were put on a cereal elimination diet (oats, wheat, rye, and barley) and skin prick tests (SPT) and patch testing with cereals were performed. Open cereal challenge was performed to confirm cereal allergy. RESULTS: Cereal challenge was positive in 66 (73%) of the children with CMA. Of them, 17% reacted with immediate reactions and delayed-onset reactions were seen in 83% of the children. SPT was positive in 23%, patch test in 67%, and either SPT or patch test was positive in 73% of the children with cereal allergy. SPT gave the best positive predictive value, whereas SPT together with patch test gave the best negative predictive value. CONCLUSIONS: Residual symptoms, such as eczema or gastrointestinal symptoms in CMA children may be a sign of undetected allergy to other food antigens. SPT with cereals aids in diagnosing cereal allergy in small children, especially when used together with patch testing.     

西南地区慢性荨麻疹皮肤点刺试验变应原检测分析

目的：了解西南地区慢性荨麻疹患者的过敏情况，为预防和治疗慢性荨麻疹提供依据。方法：采用国际标准方法的皮肤点刺试验，对225例慢性荨麻疹患者做20种过敏原测定，并设阳性（组胺）及阴性（生理盐水）对照；以阳性为对照判断标准。结果：慢性荨麻疹患者蟑螂阳性率为42.6%，粉尘螨41.7％，户尘螨37.3%，律草花粉26.6%，大蚂蚁19.5%，法国梧桐18.6%，芝麻12.8%，狗毛10.2%，酵母菌9.7%，艾蒿花粉8.0%，烟曲霉菌7.1%，玉米花粉7.1%,猫毛6.6%，松花粉5.3%，家鼠5.3％，黄鳝4.4%，香烟4.0%，花生3.5%，鸡蛋清3.1%，牛奶3.1%。结论：重庆地区慢性荨麻疹患者主要过敏原为尘螨（包括粉尘螨和户尘螨），其次为樟螂和律草花粉。在可检测到过敏原的患者中大多数同时对多种过敏原过敏。     

藜草花粉过敏性哮喘诊断试验的研究

目的 比较藜草花粉变应原皮肤挑刺试验（ＳＰＴ），支气管激发试验（ＢＰＴ）、血清特异性ＩｇＥ（ｓＩｇＥ）的关系，并评估上述试验对藜草花粉过敏性哮喘的诊断价值。方法 对４０例秋季哮喘发作的病人同时进行以上试验。     

Eczematous reactions to food in atopic eczema: position paper of the EAACI and GA2LEN

Food allergy and atopic eczema (AE) may occur in the same patient. Besides typical immediate types of allergic reactions (i.e. noneczematous reactions) which are observed in patients suffering from AE, it is clear that foods, such as cow's milk and hen's eggs, can directly provoke flares of AE, particularly in sensitized infants. In general, inhaled allergens and pollen-related foods are of greater importance in older children, adolescents and adults. Clinical studies have revealed that more than 50% of affected children with AE that can be exacerbated by certain foods will react with a worsening of skin eczema either alone or in addition to immediate symptoms. Adolescents and adults may also react to foods, but reactions to 'classical' food allergens, such as hen's eggs and cow's milk, are not as common as in childhood. Some patients with AE do react to pollen-associated foods. Food-induced eczema should not be neglected by the allergologist: On the one hand, food can be a relevant trigger factor of persistent moderate-to-severe AE; on the other hand, unnecessary diets which are not based on a proper diagnosis may lead to malnutrition and additional psychological stress on patients suffering from AE. Eczematous reactions to food can only be diagnosed by a thorough diagnostic procedure, taking into account the patient's history, the degree of sensitization and the clinical relevance of the sensitization. The latter has often to be proven by oral food challenges. Upon oral food challenge it is most important to evaluate the status of the skin with an established score (e.g. SCORAD, EASI) after 24 h and later because otherwise worsening of eczema will be missed.     

Geographical variation in the prevalence of positive skin tests to environmental aeroallergens in the European Community Respiratory Health Survey I

BACKGROUND: Many studies have reported the prevalence of sensitization using skin prick tests. However, comparisons between studies and between regions are difficult because the number and the type of allergens tested vary widely. Using the European Community Health Respiratory Survey I data, the geographical variation of sensitization to environmental allergen as measured by skin tests was established. METHODS: Adults aged 20-44 years, living in 35 centres in 15 developed countries, underwent skin tests for allergy to nine common aeroallergens: Dermatophagoides pteronyssinus, timothy grass, cat, Cladosporium herbarium, Alternaria alternata, birch, Olea europea, common ragweed and Parietaria judaica. The age-sex standardized prevalence of sensitization was determined and centres with high (95% confidence interval above and excluding study median) and low prevalence (95% confidence interval below and excluding study median) of sensitization to each allergen and to any of the nine allergens were identified. RESULTS: There was substantial geographical variation in the prevalence of sensitization to each of the nine allergens tested and in the prevalence of sensitization to any allergen (lowest 17.1%, median 36.8% and highest 54.8%). Sensitization to D. pteronyssinus, grass pollen and cat were usually the most prevalent (median between centre 21.7%, 16.9% and 8.8%, respectively). Timothy grass sensitization was higher than that for any other pollen species. CONCLUSIONS: As expected, geographical variations of sensitization to environmental allergen were observed across centres. These findings were compatible for those observed with serum-specific IgE. Skin tests can be used to assess the geographical distribution of allergens in a multicentric epidemiological survey.     

Sensitivity and specificity of specific IgE,skin prick test and atopy patch test in examination of food allergy

The aim of this study is the evaluation of the specificity and sensitivity of the skin prick tests (SPTs), specific IgE and atopy patch tests (APTs) in atopic dermatitis patients suffering from food allergy. A total of 301 patients were examined, complete dermatological and allergological examination was performed in all patients. The food allergy was confirmed to peanuts in 62 patients (20%), to egg in 16 patients (5%), to soy in 9 patients (3%), to wheat in 12 patients (4%) and to cow milk in 6 patients (2%). The specificity of SPT, specific IgE and APT is considered as good; the sensitivity of APT is low. The positive results in isolation cannot confirm the food allergy; however, together with other diagnostic methods, such as clinical history and open exposure test, these tests are valuable tool in examination of food allergy.