Abstract: Objective To explore the value of abdominal ultrasound in the differential diagnosis of neonatal food protein-induced enterocolitis syndrome (NFPIES) and early neonatal necrotic enterocolitis (NEC). Methods Twenty-one children diagnosed as NFPIES and early NEC (n=48) were selected in this study. Data of sex, gestational age, clinical symptoms (vomiting, abdominal distension and bloody stool) and the percentage of blood eosinophils (EO) within 8 hours of clinical symptoms were collected. The time of the first abdominal ultrasound examination of all children was within 8 hours of the occurrence of clinical symptoms, and the interval between the abdominal ultrasound examination and the first examination was 8-24 hours. The changes of abdominal ultrasound signs (intestinal wall pneumatosis, intestinal peristalsis, intestinal wall thickening and peritoneal effusion) were dynamically compared. Results There were no significant differences in general baseline data between the NFPIES group and the early NEC group. The proportion of peripheral blood EO and the proportion of children with EO ratio≥0.05 were significantly higher in the NFPIES group than those in the early NEC group (P＜0.01). The proportion of children with positive abdominal ultrasound signs was lower in the NFPIES group than that in the early NEC group (P＜0.05). The ultrasonographic signs of peristalsis showed slowing at the diseased site, and the remaining peristalsis was normal without peristalsis disappearance or peritoneal effusion. In the re-examination of abdominal ultrasound, the ultrasound signs of gas in the intestinal wall and slowing of bowel movement were significantly lower in the NFPIES group than those with positive abdominal ultrasound examination for the first time (P＜0.05), while there was no significant difference in the proportion of four children with positive abdominal ultrasound signs in the early NEC group compared with the first examination. In the re-examination of abdominal ultrasound, the proportion of four children with positive ultrasound signs was lower in the NFPIES group than that in the early NEC group (P＜0.01). Conclusion Abdominal ultrasound signs help to distinguish NFPIES from early NEC, and dynamic observation of its changes is of greater significance.

Key words: infant, newborn, anaphylaxis, enterocolitis, necrotizing, ultrasonography, food protein-induced enterocolitis syndrome