食物过敏与儿童特应性皮炎相关性及其诊断

大约1/3中到重度特应性皮炎患儿存在食物过敏,但食物过敏是否会诱发或加重特应性皮炎患儿的湿疹样皮损仍存在争议.食物过敏可以诱发特应性皮炎患儿的两种反应,非湿疹样反应和湿疹样反应.前者为IgE介导,诊断相对比较简单,多数情况下借助病史、皮肤点刺试验及特异性IgE抗体水平等即可明确诊断.后者为细胞介导,诊断必须借助口服食物激发试验.如果没有条件做食物激发试验时,也可以借助诊断性的饮食回避来明确可疑过敏食物.     

225例特应性皮炎患儿血清中食物特异性IgE抗体检测及其意义

特应性皮炎的发病机制至今不是很清楚。本研究旨在通过检测患儿血清中食物特异性IgE（sIgE）抗体，明确北京及周边地区儿童特应性皮炎相关的食物变应原，探讨食物过敏与儿童特应性皮炎的相关性。     

食物特应性斑贴试验及其应用

食物引起的过敏反应可诱发或加重特应性皮炎。特应性斑贴试验是在皮肤上使用完整的蛋白质过敏原进行斑贴的诊断性试验,与迟发型过敏反应相关。食物特应性斑贴试验可以用来检测食物引起的迟发型过敏反应,帮助特应性皮炎或食物过敏患者明确相关食物过敏原,指导病因学诊断。该文对食物特应性斑贴试验的免疫学机制、方法学及其与临床的相关性进行综述。     

食物过敏与儿童特应性皮炎

食物过敏是婴幼儿常见的过敏反应,尤其在特应性皮炎患者中更为常见。目前特应性皮炎与食物过敏的相关性尚不完全清楚。食物过敏是特应性皮炎患者家长极其关注的一个问题,在特应性皮炎患者中关于食物过敏诊断和管理存在诸多误区。该文为了增加对食物过敏的正确认知,从而进行有效地诊断及科学的管理特应性皮炎。目前诊断的金标准为双盲安慰剂对照食物激发试验,在临床管理中需注意正常母乳喂养,避免盲目忌食,按时添加辅食,合理使用益生菌和预防接种。     

食物过敏在异位性皮炎发病中的作用

食物过敏在异位性皮炎发病中的作用是一个争议很大的课题。本文复习了 IgE 介导的Ⅰ型变态反应的基本特性,着重于迟发相 IgE 反应及其与异位性皮炎的相关性.另外,还介绍了肠道吸收蛋白到达皮肤肥大细胞途径的临床研究资料,食物激发的临床反应及饮食限制,以及判断食物对某一患者是否致敏的简便方法。     

马拉色菌与特应性皮炎

特应性皮炎的病因和发病机制目前尚未完全明确,近年研究发现马拉色菌可能诱发该病,综述马拉色菌在特应性皮炎患者的体表分布、针刺反应试验、血清IgE水平、斑贴试验、细胞和细胞因子水平以及抗马拉色菌感染的治疗等方面对马拉色菌与特应性皮炎及其相关性的研究,从而为诊断和治疗特应性皮炎提供理论基础。     

婴幼儿特应性皮炎的过敏原分析

目的了解食物和吸入过敏原在婴幼儿特应性皮炎中所占的比例以及主要的食物过敏原。方法对95例患儿进行婴幼儿过敏原筛查(phadiatop infant),并同85例健康儿童进行比较。同时对患儿血清进行吸入过敏原筛查(phadiatop)及多价食物过敏原筛查(fx5E),并从95例中随机抽取60例进行几种常见食物的特异性IgE(sIgE)检测。结果95例患儿组婴幼儿过敏原筛查阳性55例(57.89%),85例正常儿童中阳性16例(18.82%)两者比较差异有显著性意义(P<0.01)。患儿组多价食物过敏原阳性54例(56.8%),吸入过敏原阳性19例(20%),两者比较差异有显著性意义(P<0.01)。食物特异性IgE检测中血清浓度在3级以上的,鸡蛋白为23.3%,牛奶为11.7%,小麦为10%,蛋黄为6.7%,花生为6.7%,黄豆为1.67%。结论婴幼儿特应性皮炎患儿中过敏原检测阳性率高于正常儿童,其中食物IgE的阳性率比吸入IgE的阳性率更高,食物过敏原在婴幼儿特应性皮炎中占有重要地位。     

马拉色菌与特应性皮炎

特应性皮炎的病因和发病机制目前尚未完全明确，近年研究发现马拉色菌可能诱发该病，综述马拉色菌在特应性皮炎患者的体表分布、针刺反应试验、血清IgE水平、斑贴试验、细胞和细胞因子水平以及抗马拉色菌感染的治疗等方面对马拉色菌与特应性皮炎及其相关性的研究，从而为诊断和治疗特应性皮炎提供理论基础。     

婴幼儿湿疹和特应性皮炎的血清食物特异性IgE检测

为了解食物变应原在婴幼儿湿疹和特应性皮炎(AD)中的比例及作用,采用免疫CAP诊断系统,以荧光酶联免疫技术对581例婴幼儿湿疹和AD患儿进行血清食物特异性IgE(sIgE)检测,并从中随机抽取114例(19.6%)患儿进行血清多价食物变应原筛查(fx5E)及吸入变应原筛查(Phadiatop)的检测并比较.结果:581例患儿中334例血清食物sIgE升高,阳性率57.5%,其中AD患儿的血清食物sIgE阳性率62.7%;湿疹患儿的血清食物sIgE阳性率56.4%,两者之间差异无显著性意义.血清多价食物变应原阳性率57.9%;血清吸入变应原阳性率19.3%,两者比较差异有显著性意义(P＜0.01).在婴幼儿湿疹和AD患儿中食物IgE阳性率比吸入物IgE阳性率更高,变应原IgE的检测对防治婴幼儿湿疹和AD具有重要意义.     

特应性斑贴试验在诊断特应性皮炎患儿鸡蛋、牛奶过敏中的价值

目的 探讨特应性斑贴试验(APT)在诊断特应性皮炎(AD)患儿食物过敏中的价值.方法 以中国儿童最常见的过敏食物--鸡蛋、牛奶为抗原,同时采用APT和皮肤点刺试验(SPT)对68例AD患儿进行鸡蛋和牛奶变应原的诊断性检测,并以开放性食物激发试验验证.结果 本组68例AD患儿中,经食物激发试验证实鸡蛋过敏58例(85.3%),牛奶过敏40例(58.8%),两者同时过敏34例(50.0%).98例阳性食物激发试验47例表现为迟发反应,10例为速发反应,41例为混合反应.APT诊断鸡蛋(牛奶)过敏的敏感性、特异性、阳性预测值、阴性预测值和与食物激发试验的一致率分别为96.6%(67.5%)、90.0%(82.1%)、98.2%(84.4%)、81.8%(63.9%)和95.6%(73.5%),而SPT为37.9%(30.0%)、100.0%(89.3%)、100.0%(80.0%)、21.7%(47.2%)和47.1%(54.4%).APT诊断迟发反应的阳性率显著高于SPT(P<0.01). APT、SPT联合与APT单独应用在诊断鸡蛋和牛奶过敏的差异无统计学意义(并联诊断与APT单独诊断敏感性比较:鸡蛋x2=0.509,牛奶x2=0.549,P>0.05;串联诊断与APT单独诊断特异性比较:鸡蛋P=1.000,牛奶x2=3.514,P>0.05).结论 APT对以迟发反应为主要临床表现的食物过敏的诊断价值显著优于SPT.联合APT和SPT较之单独应用APT并不能提高诊断AD鸡蛋/牛奶过敏的效能.     

Does food allergy cause atopic dermatitis? Food challenge testing to dissociate eczematous from immediate reactions

The objective is to evaluate and diagnose, in a controlled setting, suspected food allergy causation in patients hospitalized for management of severe, unremitting atopic dermatitis (AD). Nineteen children were hospitalized at Oregon Health and Science University with atopic dermatitis from 1986 to 2003 for food restriction, then challenge, following standard recommendations. Challenges were prioritized by categories of (a) critical foods (e.g., milk, wheat, egg, soy); (b) important foods; and (c) other suspected foods. Patients were closely observed for evidence of pruritus, eczematous responses, or IgE-mediated reactions. If results were inconsistent, double-blind, placebo-controlled food challenge was performed. A total of 17 children with atopic dermatitis were assessed. Two could not be fully evaluated, thus were excluded from data tabulations. Only one positive eczematous food response was observed of 58 challenges. Three children had well-documented histories of food-induced IgE-mediated anaphylactoid or urticaria reactions to seafood and/or nuts and were not challenged with those foods. Atopic dermatitis, even in the highest-risk patients, is rarely induced by foods. Undocumented assumptions of food causation detract from proper anti-inflammatory management and should be discouraged. Immediate IgE-mediated food reactions are common in atopic dermatitis patients; such reactions are rapid onset, typically detected outside the clinic, and must be distinguished from eczematous reactions. Diagnosis of food-induced eczema cannot be made without food challenge testing. Such tests can be practical and useful for dispelling unrealistic assumptions about food allergy causation of atopic dermatitis.     

Immediate contact reactions to cow's milk and egg in atopic children.

Forty children (0-5 years old), presented with immediate contact urticaria, rash and often atopic dermatitis (n = 34). Redness or urticaria around the mouth appearing after consuming cow's milk or egg, were the major complaints in all. These symptoms suggested a food-induced immediate contact reaction, which can be immune-mediated or irritative. To reinduce this reaction, a skin provocation test, called SAFT, was performed. SAFT stands for Skin Application Food Test. This test is based on direct skin contact, during a maximum of 30 min with food in its 'ordinary consumptive state'. The SAFT can be regarded as a 'physiological' provocation patch test. If positive, contact urticaria develops most often within a few minutes. The results of SAFT and IgE RAST correlated significantly well. Total IgE values were not informative. The rapid onset of the SAFT reaction, induced by proteins, supported by RAST results, strongly indicates an immune-mediated mechanism. In 52% of the 34 patients with atopic dermatitis, dermatitis was exacerbated following food-to-skin contact. Immune-mediated contact reactions to foods play an important role in (dermal) food allergy.     

Milk causes a rapid urticarial reaction on the skin of children with atopic dermatitis and milk allergy

Open skin challenge test with whole milk and its large and small molecular fractions was performed on intact skin of children with atopic dermatitis and suspicion of milk allergy. Of the 51 children challenged with milk 35 reacted within minutes with contact urticaria. The large molecular (m.w. greater than 10,000 d) fraction gave an urticarial reaction as often as whole milk, whereas the small molecular fraction gave only a few positive reactions. These were obviously caused by alpha-lactalbumin which was present only in small amounts in the small molecular fraction. These findings indicate that immediate contact allergy to relevant food allergens can be very common in children with atopic dermatitis and that the large molecular antigens readily penetrate children's skin.     

Frequency of atopic dermatitis and relevance of food allergy in adults in Germany

Many factors may aggravate atopic dermatitis. The aim of this study was to determine the frequency of atopic dermatitis in an unselected population sample and to evaluate the role of food allergy. Patients with atopic dermatitis were recruited from the population in Berlin, Germany, using a postal questionnaire. Skin prick tests for allergens were performed, followed by food challenges. A total of 1739 questionnaires was returned. In all, 23.5% of patients stated that they had atopic dermatitis, and 146 persons (8.4%) fulfilled our atopic dermatitis criteria after a detailed telephone interview. Of these, 111 were examined, and 28 (1.6%) were identified as currently suffering from atopic dermatitis. Twenty-seven patients were further evaluated: 9/27 were found to be skin prick test negative, 19/27 were skin prick test positive either to pollen and/or food allergens. Nine of 27 were challenged with the suspected food allergen: 1/9 showed a worsening of the eczema, 3/9 had oral symptoms, and 5/9 were negative. In conclusion, only 20% of adults with a positive history of atopic dermatitis show active eczema lesions at a given time point. The data indicate that most individuals with atopic dermatitis were sensitized against pollen allergens and according to that, pollen-associated food allergens. A non-selected AD patient cohort does not frequently suffer from clinically relevant pollen-associated food allergy.     

Food allergy

Food allergy is defined by a specific sensitization against food allergens which is associated with a clinical reaction. Immediate reactions are most common and the skin is most often involved in food allergy. Most food allergies are IgE‐mediated although eczema reactions in atopic dermatitis and in hematogenous contact dermatitis to foods can be mediated by specific T‐lymphocytes. Only few foods are responsible for the majority of most reactions in childhood. In adults up to 60% of all food allergic reactions are due to cross reactions between foods and inhalative allergens. A stepwise procedure which takes individual factors into account is necessary in the diagnostics of food allergy. The diagnostic algorithm in food allergy is not significantly different from that of other allergies. The oral provocation is the only method to prove food allergy in patients without a convincing history. A specific elimination diet is the only intervention which has been proven to be effective. Further therapeutic approaches are still under study and include specific immunotherapy, specific oral tolerance induction and treatment with anti‐IgE antibodies.     

Food Hypersensitivity and Dietary Management in Atopic Dermatitis

Abstract: Although immune dysfunction it known to play an integral rote In the development of atopic dermatitis, no clear delineation of the underlying pathogenic mechanism(s) responsible for this disorder has been proposed. Several factors are known to trigger flares of ttople dermatitis, in the extrinsic form of this disorder, food and airborne allergans may provoke Hares of eczema. Research Implicating food hypersensitivity in the pathogenesis of atopic dermatitis includes studies of food sliergen avoidance In newborn Infants at high risk for atopic disease, Investigations of children with blinded food challenges, and therapeutic trials of allergen-elimination diets. Taken together, these studies demonstrate a significant pathogenic role for food hypesensltivity In about one-third of children with atopic dermatitis.     

Atopic dermatitis,inhalant allergy and food allergy: A paediatric approach

Food and inhalant allergens have also been identified as potential trigger factors of atopic dermatitis symptoms. Here we aimed to investigate relationships between atopic dermatitis and inhalant‐food allergen sensitization in Turkish children with atopic dermatitis. We included 70 patients (42 male, 28 female) with atopic dermatitis and 45 controls (30 male, 15 female) with no atopy, no atopy familial history, no atopy clinical findings no atopic dermatitis. We noted patients' and controls' age, gender, passive smoking exposure, atopy, xerosis, bath water temperature, shower gel type, clothes detergent type, blood hemoglobin, blood eosinophil count, blood eosinophil percent, values of serum immunoglobulin E, serum immunoglobulin A, serum immunoglobulin G, serum immunoglobulin M, results of inhalant allergen, and food allergen testing. We found that nine cases had inhalant allergen sensitization and 21 cases had food allergen sensitization. There were significant relationships between cases and controls in terms of count of eosinophil and percent of eosinophil (P = .008, P = .009, respectively). Humoral and cellular allergen‐specific immune responses to food and inhalant allergens can be detected in patients with atopic dermatitis. Accordingly, we believe that blood eosinophil count and percent are more valuable laboratory parameters than serum total IgE for following patients with atopic dermatitis.     

Association factors for atopic dermatitis in nursery school children in Ishigaki islands - Kyushu University Ishigaki Atopic Dermatitis Study (KIDS)

Atopic dermatitis (AD) is a multifactorial disease that usually decreases the quality of life of affected patients. The purpose of this study was to evaluate the associated factors for atopic dermatitis, asthma, rhinitis, and food allergy by physical examination of the skin and a questionnaire in nursery school children in Ishigaki Island, Okinawa, Japan. Enrolled in this study were 460 children from 0 to 6 years of age. Physical examination of skin symptoms and blood tests were performed. Information on past history and family history of atopic dermatitis, asthma, rhinitis, and food allergy were collected by questionnaire. The prevalence of atopic dermatitis was 12.2% (56/460). The cumulative prevalence of asthma, rhinitis, and food allergy was 19.9% (91/458), 3.3% (15/457), and 5.5% (25/456), respectively. In multivariate analysis, maternal history of rhinitis, atopic dermatitis siblings, past history of asthma and food allergy, and elevation of total IgE were significantly related to atopic dermatitis. A high total IgE level was a strong risk factor specific for atopic dermatitis in this population.