Allergic Enterocolitis in A Preterm Newborn

We report the case of an infant born at 28 weeks of gestation with a history of intestinal dysmotility over the first week of life, which was solved with the introduction of erythromycin. The infant was fed with breast milk and sporadic doses of special formula for preterm newborns. On the 17th day of life, post conceptional age of 30 weeks, she presented an episode of necrotizing enterocolitis treated with antibiotics. On the 45th day of life, post conceptional age of 34 weeks, the infant presented episodes of apnea, hemodynamic instability, abdominal distension, vomiting and mucous and bloody stools. Owing to the suspicion of a new episode of necrotizing enterocolitis, feeding was stopped and antibiotic therapy was started. Hypereosinophilia was detected in peripheral blood and tests were positive for specific IgE antibodies to cow's milk proteins. Antibiotics were stopped after negative sepsis workups and feeding with breastmilk and extensively hydrolyzed formula was resumed. The newborn presented with good tolerance.Diagnosing allergy to cow's milk protein in a newborn infant requires a high degree of suspicion, as it presents with non-specific symptoms. In most cases it manifests as non-IgE-mediated proctocolitis and cases of enterocolitis with specific IgE antibodies to cow's milk proteins are rare. Some authors argue that the development of cow's milk protein allergy requires an immunological maturation level not present before a gestational age of 30-32 weeks. Therefore, in preterm newborns, there may be an asymptomatic period of life with subsequent development of an allergy. In the case described, the diagnosis of IgE-mediated cow's milk protein allergy was confirmed at 34 weeks of post conceptional age. However, the question remains whether the previous digestive symptoms were related to the allergy subsequently diagnosed.