Differential Diagnosis for Sudden-Onset Vomiting in a 5-Day-Old Boy
Single Most Likely Diagnosis
- Necrotizing Enterocolitis (NEC): This condition is a leading cause of morbidity and mortality in preterm infants. The presence of pneumatosis intestinalis on the abdominal radiograph, along with the clinical presentation of vomiting (especially with a coffee-grounds appearance), abdominal distension, tenderness, and decreased bowel sounds, strongly suggests NEC. The patient's preterm birth and history of being fed via nasogastric tube also increase the risk for NEC.
Other Likely Diagnoses
- Gastroesophageal Reflux Disease (GERD): Although less likely given the specific radiographic findings, GERD could cause vomiting. However, the presence of pneumatosis intestinalis and the coffee-grounds appearance of the emesis make this less probable.
- Infectious Gastroenteritis: This could cause vomiting and abdominal distress, but the radiographic findings and the specific clinical context (preterm infant in the NICU) make NEC more likely.
- Intestinal Obstruction: Conditions like intestinal atresia or volvulus could present with vomiting and abdominal distension. However, the pneumatosis intestinalis is more characteristic of NEC.
Do Not Miss Diagnoses
- Perforated Viscus: Although the presence of pneumatosis intestinalis suggests NEC, it's crucial not to miss a perforated viscus, which would require immediate surgical intervention. The clinical presentation and radiographic findings could overlap, making it essential to consider this diagnosis.
- Sepsis: Preterm infants are at high risk for sepsis, which can present with non-specific symptoms including vomiting, abdominal distension, and lethargy. Sepsis can coexist with or mimic NEC, and missing this diagnosis could be fatal.
- Hirschsprung's Disease: Enterocolitis associated with Hirschsprung's disease can present similarly to NEC, including with pneumatosis intestinalis. Although less common, this diagnosis should be considered, especially if the infant does not respond to treatment for NEC.
Rare Diagnoses
- Congenital Anomalies (e.g., duodenal atresia, jejunoileal atresia): These conditions could cause intestinal obstruction and vomiting but would typically be identified earlier in life or have more distinct radiographic findings.
- Inborn Errors of Metabolism: Certain metabolic disorders can cause vomiting and abdominal symptoms in the neonatal period. While rare, these conditions should be considered if the infant does not respond to standard treatments for more common conditions.