Diffuse pneumatosis intestinalis caused by food protein-induced enterocolitis-a case report.

Background: Pneumatosis intestinalis (PI) is characterized by the presence of gas within the intestinal wall and is most commonly associated with necrotizing enterocolitis (NEC) in preterm neonates. However, PI can also be observed in term infants and older children, where its etiology is more diverse and requires careful consideration of a broad differential diagnosis. Food protein-induced enterocolitis syndrome (FPIES), usually triggered by cow's milk protein (CMP), is a non-IgE-mediated gastrointestinal food allergy. It typically manifests in early infancy with recurrent vomiting, diarrhea, poor weight gain, or failure to thrive, but severe complications such as PI are rare. Case Description: We report the case of a full-term female neonate who presented at 2 weeks of age with a 5-day history of persistent vomiting and bloody stools. On admission, she appeared clinically unwell, with metabolic acidosis and elevated lactate levels. Abdominal examination revealed distension, and imaging demonstrated diffuse PI without evidence of perforation. The patient was admitted to the pediatric intensive care unit, where she was managed conservatively with bowel rest, total parenteral nutrition, and empiric antibiotics. Extensive microbiological and viral investigations were negative. Over 2 weeks, her clinical status improved, and follow-up imaging confirmed the resolution of PI. An amino acid-based formula was introduced, which was well tolerated without recurrence of symptoms. She was subsequently discharged in good condition and has remained well on follow-up, with normal growth and development. Conclusions: Although PI is mainly present in preterm infants as a sign of NEC, it can be present in infants beyond the neonatal period. The differential diagnosis of PI is wide and depends on the age of presentation. FPIES secondary to CMP is a more common disease, and can present with severe manifestations, and should be suspected when other diagnoses are ruled out.