Awareness or neglecting the diagnosis of cow milk protein allergy in the neonatal period.

Background and objectives: Cow milk protein allergy (CMPA) can mimic surgical disease, gastroenteritis, sepsis, and necrotizing enterocolitis in the neonatal period. For this reason, we aimed to evaluate the clinical features, differential diagnosis, and treatment methods of neonates with CMPA.

Methods and study design: The charts of twenty-six breastfed full-term and preterm newborns presenting with CMPA between October 2018 and February 2021 were retrospectively reviewed. The clinical symptoms, laboratory findings, and methods used in diagnosis and treatment were analyzed.

Results: CMPA was diagnosed in preterm infants 50% (n=13) at the same rate as in full-term infants 50% (n=13) between 32 to 38 weeks corrected age (median 36 weeks). Among patients with CMPA, 69.2% (n=18) had blood in the stool at the onset. Cow's Milk-related Symptom Score score was found to be significantly higher prior to diagnosis vs. after treatment with the cow milk protein-free mom's milk diet [12(11-13) vs. 4(3-5), p<0.001]. Seventy-two hours after the commencement of the mothers' elimination diet, macroscopic blood in stool disappeared in all patients except one patient. Oral food challenge (OFC) for the diagnosis of CMPA was carried out on all (n=26) neonates. Eosinophilia was seen in 46.2% of patients (n=12). The methemoglobin concentration was 1.1 to 1.5% (median 1.3%).

Conclusions: CMPA should be kept in mind for well-appearing preterm and full-term infants suspected of necrotizing enterocolitis and gastroenteritis, respectively, presenting with bloody stool and eosinophilia. The use of OFC can be implemented since neonates were very well monitored in the neonatal intensive care unit. Treatment is possible by continuing breastfeeding.