Cow’s milk protein allergy presenting as recurrent necrotizing enterocolitis in preterm neonates: A Case Report

Abstract

Introduction: Necrotizing enterocolitis (NEC) is a major cause of morbidity in preterm infants. Cow’s milk protein allergy (CMPA) may mimic NEC or predispose to intestinal injury, but recurrent NEC associated with CMPA is rarely reported.

Objective: This study reviewed recurrent NEC in a preterm female infant born at gestational
age (GA) 34 weeks presented with recurrent bloody stools at day of life (DOL) 27 despite prior recovery from the first NEC stage IIB on DOL 9. Given the temporal relationship with cow’s milk protein exposure and subsequent clinical improvement with cow’s milk protein elimination, CMPA was strongly suspected as a contributing factor.

Case presentation: A preterm female infant born at GA 34 weeks, birth weight 2030 g, with no perinatal complications was presented with grossly bloody stools on DOL 1 and empiric antibiotics were initiated. On DOL 9, the infant developed hypothermia and recurrent bloody stools. Laboratory tests revealed leukocytosis and metabolic acidosis, while abdominal radiographs demonstrated pneumatosis intestinalis and portal venous gas, consistent with NEC stage IIB. Management included bowel rest, and broad-spectrum antibiotics. Feeding was reintroduced with breast milk plus preterm formula after being kept nil per os (NPO) for 10 days. Feedings were advanced after NPO for 10 days. At DOL 27, after advanced with breast milk plus preterm formula for 8 days, the infant developed recurrent bloody stools despite prior recovery. Stool cultures were negative, and abdominal examination revealed marked distension with hypoactive bowel sounds. Recurrent NEC was diagnosed. After NPO 10 days and broad-spectrum antibiotics. Feeding with breast milk that maternal eliminated diary product
and extensive hydrolysate formula was reintroduced until full feed. After change of formula promptly showed resolution of symptoms with improved radiological findings. Given the temporal relationship with cow’s milk protein exposure and subsequent clinical improvement with cow’s milk protein elimination, CMPA was strongly suspected as a contributing factor.

Conclusion: This case highlights the complex interplay between NEC and CMPA. CMPA should be considered in preterm infants, our case most likely represents CMPA as a predisposing condition that increased intestinal vulnerability to true NEC episodes.