Eigenmann P A, Sicherer S H, Borkowski T A, Cohen B A, Sampson H A
Department of Pediatrics, University of Geneva, Geneva, Switzerland.
Pediatrics. 1998 Mar;101(3):E8. doi: 10.1542/peds.101.3.e8.
There is a growing body of clinical and laboratory evidence to support the notion that food allergy plays a role in the pathogenesis of atopic dermatitis (AD). However, the incidence of IgE-mediated food allergy in children with AD is not well established.
A prospective study to determine the prevalence of IgE-mediated food hypersensitivity among patients referred to a university-based dermatologist for evaluation of AD.
University hospital pediatric dermatology clinic.
A total of 63 patients with AD were recruited (35 male; 32 white, 24 African-American, 7 Asian).
Patients were assigned an AD symptom score (SCORAD) and were screened for food-specific serum IgE antibodies to six foods (milk, egg, wheat, soy, peanut, fish) known to be the most allergenic in children. The levels of food-specific serum IgE were determined by the CAP System fluoroscein-enzyme immunoassay (CAP); patients with a value >/=0.7 kIUa/L were invited for an additional allergy evaluation. Those with CAP values below the cutoff were considered not food allergic. Patients were considered to be allergic if they met one of the following criteria for at least one food: 1) reaction on food challenge; 2) CAP value more than the 95% confidence interval predictive for a reaction; 3) convincing history of an acute significant (hives, respiratory symptoms) reaction after the isolated ingestion of a food to which there was a positive CAP or prick skin test.
A total of 63 patients (median age, 2.8 years; median SCORAD, 41.1) were recruited; 22 had negative CAP values (without a significant difference in age or SCORAD score, compared with the 41 with positive specific IgE values). Further allergy evaluation was offered to the 41 remaining patients; 10 were lost to follow-up and 31 were evaluated further. Of these, 19 underwent a total of 50 food challenges (36 double-blind, placebo-controlled, and 14 open), with 11 patients experiencing 18 positive challenges (94% with skin reactions). Additionally, 6 patients had a convincing history with a predictive level of IgE; 5 had a convincing history with positive, indeterminate levels of IgE; and 1 had predictive levels of IgE (to egg and peanut) without a history of an acute reaction. Overall, 23/63 (37%; 95% confidence interval, 25% to 50%) had clinically significant IgE-mediated food hypersensitivity without a significant difference in age or symptom score between those with or without food allergy.
Approximately one third of children with refractory, moderate-severe AD have IgE-mediated clinical reactivity to food proteins. The prevalence of food allergy in this population is significantly higher than that in the general population, and an evaluation for food allergy should be considered in these patients.
越来越多的临床和实验室证据支持食物过敏在特应性皮炎（AD）发病机制中起作用这一观点。然而，AD患儿中IgE介导的食物过敏的发生率尚未明确。
一项前瞻性研究，以确定转诊至大学皮肤科医生处评估AD的患者中IgE介导的食物超敏反应的患病率。
大学医院儿科皮肤科诊所。
共招募了63例AD患者（35例男性；32例白人，24例非裔美国人，7例亚洲人）。
为患者分配AD症状评分（SCORAD），并筛查针对已知在儿童中最具致敏性的六种食物（牛奶、鸡蛋、小麦、大豆、花生、鱼）的食物特异性血清IgE抗体。通过CAP系统荧光酶免疫测定法（CAP）测定食物特异性血清IgE水平；IgE值≥0.7 kIUa/L的患者被邀请进行额外的过敏评估。CAP值低于临界值的患者被认为无食物过敏。如果患者至少对一种食物符合以下标准之一，则被认为过敏：1）食物激发试验有反应；2）CAP值超过反应预测的95%置信区间；3）有令人信服的病史，即在单独摄入CAP或点刺皮肤试验呈阳性的食物后出现急性严重（荨麻疹、呼吸道症状）反应。
共招募了63例患者（中位年龄2.8岁；中位SCORAD为41.1）；22例CAP值为阴性（与41例特异性IgE值为阳性的患者相比，年龄或SCORAD评分无显著差异）。对其余41例患者进行了进一步的过敏评估；10例失访，31例接受了进一步评估。其中，19例共进行了50次食物激发试验（36次双盲、安慰剂对照试验和14次开放试验），11例患者出现18次阳性激发试验（94%有皮肤反应）。此外，6例患者有令人信服的IgE预测水平病史；5例有令人信服的IgE阳性但不确定水平的病史；1例有IgE预测水平（对鸡蛋和花生）但无急性反应病史。总体而言，63例中有23例（37%；95%置信区间为25%至50%）有临床上显著的IgE介导的食物超敏反应，有或无食物过敏的患者在年龄或症状评分上无显著差异。
约三分之一难治性、中度至重度AD患儿对食物蛋白有IgE介导的临床反应性。该人群中食物过敏的患病率显著高于一般人群，这些患者应考虑进行食物过敏评估。
