Medina R R, Mora P M
Servicio de alergia e inmunología, Hospital de Especialidades, México.
Rev Alerg Mex. 1996 Jan-Feb;43(1):9-12.
Our objective was to evaluate the diagnostic value of RAST in children with symptoms of airways allergy and probable food allergy. We studied 17 children under 6 years old with rhinitis or asthma. The underwent a food elimination diet during 4 weeks followed by weekly ambulatory oral food challenge. Cough, wheezing, dyspnea, rhinorrea and nasal itch and blockage were evaluated, daily by their parents and weekly at the hospital. We found no difference between the clinical evaluation made by their parents and at the hospital. We found 16/76 positive oral food challenges. RAST was positive in 44 foods. Cow's milk and egg were the more frequent positive foods both in oral challenge and RAST, 5 and 6, and 14 and 14, respectively. Serum IgE had an average of 350 UI/ml. RAST evaluation results were sensitivily 62.5%, specificity 43.3%; positive predictive value 22.7%, negative predictive value 81.3% and total efficacy 47.4%. We can conclude that food allergy can be a frequent cause of airways allergy symptoms in children under 6 years old and although in cases, RAST is considered the best in vitro diagnostic test, its results should be symptoms related and cautiosly interpreted.
我们的目的是评估RAST对有气道过敏症状及可能存在食物过敏的儿童的诊断价值。我们研究了17名6岁以下患有鼻炎或哮喘的儿童。他们进行了为期4周的食物排除饮食，随后每周进行门诊口服食物激发试验。咳嗽、喘息、呼吸困难、鼻分泌物增多以及鼻痒和鼻塞由家长每天评估，并每周在医院评估一次。我们发现家长进行的临床评估与在医院进行的评估之间没有差异。我们发现76次口服食物激发试验中有16次呈阳性。RAST在44种食物中呈阳性。牛奶和鸡蛋在口服激发试验和RAST中都是较常见的阳性食物，分别为5次和6次，以及14次和14次。血清IgE平均为350 UI/ml。RAST评估结果的敏感性为62.5%，特异性为43.3%；阳性预测值为22.7%，阴性预测值为81.3%，总有效率为47.4%。我们可以得出结论，食物过敏可能是6岁以下儿童气道过敏症状的常见原因，尽管在某些情况下，RAST被认为是最佳的体外诊断试验，但其结果应结合症状谨慎解读。
