日本未熟児新生児学会雑誌　第21巻　第2号　83～88頁（2009年）

日本未熟児新生児学会雑誌　21(2)：259-264；2009　

受付日：平成20．07．07

受理日：平成20．11．28

哺乳開始前に血便を呈したミルクアレルギーの一例

A Case of Cow’s Milk Allergy with Bloody Stools Before the First Feeding

八尾市立病院　小児科

Department of Pediatrics, Yao Municipal Hospital

柴田真理・土井政明・井﨑和史・道之前八重・高瀬俊夫

Mari SHIBATA, Masaaki DOI, Kazufumi IZAKI, Yae MICHINOMAE, Toshio TAKASE

Key Words：cow’s milk allergy，intrauterine sensitization，FPIES，stimulation index measured by flowcytometry（SIF）

　症例は在胎36週1日，2,145gで出生した男児。生後1時間から血便が出現した。血液検査にて白血球および好酸球は高値を示したが，CRPは低値で，止血凝固検査および腹部画像検査に異常はなかった。哺乳開始前からの血便であったため，普通ミルクで少量から哺乳を始めたが，日齢9に胆汁性嘔吐と急激な体重減少を認めた。日齢12の検査で牛乳特異的IgE抗体陽性を認め，ミルクアレルギーと診断した。禁乳とし高カロリー輸液を開始したところ，血便および胆汁性嘔吐は消失した。日齢33のリンパ球増殖反応にて，卵白アルブミンおよび牛乳関連蛋白質が強陽性であった。アミノ酸乳を用いた経腸栄養とし改善をみた。本症例での牛乳の感作は，出生前の経胎盤感作によるものか，あるいは新生児一過性好酸球性腸炎後に哺乳により二次的に感作したのかは明らかではないが，日齢0でも血便をみた場合には，ミルクアレルギーを念頭におく必要がある。

　We describe a 0-day-old male neonate of cow’s milk allergy with bloody stools before his first formula feeding. The patient was born at 36 weeks and 1 day of gestational age with a birth weight of 2,145g. A bloody stool appeared within one hour after birth. Laboratory findings revealed high white blood cell counts（30,400/μL）and eosinophil counts（8,664/μL）．C-reactive protein was within normal range（0.04mg/dL）, and there were no other abnormal findings on coagulation studies as well as abdominal imaging. After cow’s milk-based formula was fed little by little, he had bilious vomiting and great weight loss on day 9. He was diagnosed as IgE-dependent cow’s milk allergy based on the elevated specific IgE-antibodies to cow’s milk protein on day 12. Bloody stools and bilious vomiting disappeared when the milk feeding was stopped and total parenteral nutrition through a central venous catheter was started. Stimulation index measured by flowcytometry（SIF）that reflects lymphoproliferative response showed strong positivity to ovalbumin and cow’s milk protein such as α-casein, β-lactoglobin, and bovine albumin on day 33. Digestive symptoms were improved by changing from cow’s milk-based formula to amino acid-based formula. It remains unclear whether sensitization to cow’s milk is caused by intrauterine sensitization before birth or secondary sensitization by feeding to neonatal transient eosinophilic colitis. In conclusion, cow’s milk allergy should be taken into consideration if bloody stools are observed even before the first feeding on day 0.