日本未熟児新生児学会雑誌　第22巻　第2号　61～66頁（2010年）

日本未熟児新生児学会雑誌　22(2)：239-244；2010　

受付日：平成22．02．25

受理日：平成22．05．17

臨床経過・検査所見でミルクアレルギーが疑われたが，牛乳蛋白負荷試験で陰性であった1新生児例

A Neonatal Case Suspected of Cow’s Milk Allergy by Clinical Symptoms and Laboratory Findings, Followed by Negative Challenge Test

愛知県心身障害者コロニー中央病院　新生児科

Department of Neonatology, Aichi Human Service Center Central Hospital

立花貴史・伊藤美春・孫田みゆき・垣田博樹・寺澤かずみ・山田恭聖

Takashi TACHIBANA，Miharu ITO，Miyuki MAGOTA，Hiroki KAKITA， Kazumi TERASAWA，Yasumasa YAMADA

Key Words：cow’s milk allergy（CMA），challenge test，allergen-specific lymphocyte stimulation test （ALST）

　我々は，臨床症状・抗原除去による症状の改善でミルクアレルギーを疑い，リンパ球刺激試験も陽性であったが，牛乳蛋白負荷試験が陰性だった新生児症例を経験したので報告する。症例は在胎39週2日，3,935gで出生した男児。日齢6から嘔吐・粘血便が出現した。入院時検査で便中好酸球陽性，感染症・腸回転異常症等は否定的だった。絶食で症状が改善したためミルクアレルギーを疑い，母乳と加水分解乳で経口摂取を再開し，症状の再燃はみられなかった。リンパ球刺激試験は陽性だったが，負荷試験は陰性だった。
　新生児期発症のミルクアレルギーは多彩な症状を呈し，しばしば診断に苦慮する。負荷試験の施行率は低く，臨床症状や検査所見を組み合わせて診断されることが多い。負荷試験で児のアレルギーを適切に評価することが肝要で，さらに負荷試験未施行のCMA疑い例におけるALSTの特異度を検討する必要がある。

　We report a male neonate with suspicion of cow’s milk allergy, who was suspected to have cow’s milk allergy based on clinical symptoms and elimination of cow’s milk formula. We performed allergen-specific lymphocyte stimulation test （ALST） and challenge test. Though the former was positive, the latter was negative. He was born at 39 weeks and 2 days of gestation, with a birth weight of 3,935 g. At 6 days of age, he showed vomiting and bloody stool. Laboratory and imaging findings revealed fecal eosinophils, and he had no signs of infection and malrotation. His symptoms were improved after milk formula was stopped. He was suspected to have cow’s milk allergy, so we started his feeding with breast milk and hydrolyzed formula, then he had no symptoms as before. We demonstrated that ALST was positive, but challenge test was negative. 　Cow’s milk allergy in neonates presents with various symptoms, so it is often difficult to diagnose as cow’s milk allergy. When we will diagnose as a food allergy, challenge test is the gold standard. But in many cases with suspicion of cow’s milk allergy in neonates, challenge tests were hardly performed, and we often diagnose only based on clinical symptoms and laboratory and imaging findings. It is important to perform challenge tests for assessing their allergy to cow’s milk proteins, moreover, we have to examine specificity of ALST in neonates suspected of cow’s milk allergy.