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χ2 = 0.509，牛奶χ2 = 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χ2 = 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。

Application of atopy patch test in diagnosing egg and milk allergy among children with atopic dermatitis

Objective To evaluate the capacity of atopy patch test in diagnosis of food allergy in children with atopic dermatitis (AD).Methods Egg and milk,as the most common food allergens among Chinese children,were employed in this study.Skin prick test (SPT) and atopy patch test (APT) with fresh egg and milk were carried out in 68 children with AD.Oral food challenges in an open style were performed to confirm the diagnosis of food allergy.Resuits Of these patients,58(85.3%)were sensitive to egg,40(58.8%)to milk and 34(50.0%) to both.Of 98 patients with positive challenge,47 showed late response,10 immediate reactions.and 41 mixed reactions.The sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) and the agreement with food challenges in diagnosis of egg/milk allergy were 96.6%/67.5%.90.0%/82.1%,98.2%/84.4%,81.8%/63.9% and 95.6%/73.5%,respectively for APT alone,37.9%/30.0%,100%/89.3%,100%/80.0%,21.7%/47.2% and 47.1%/54.4%,respectively for SPT alone.APT was found to be more sensitive in diagnosis of late-phase reactions than SPT (P<0.01).No significant difference was found in the sensitivity between APT alone and the combination of APT and SPT in parallel algorithm for diagnosis of egg or milk allergy (x2=0.509,0.549,both P>0.05) or in the specificity between APT alone and that in serial algorithm( P=1.000;x2=3.514,P>0.05).Conclusions APT is superior to SPT in diagnosis of late responses to food,and the combination of SPT and APT does not facilitate the diagnosis of food or milk allergy compared with APT alone.