Differential Diagnosis for Non-Bilious Emesis in a 3-Week-Old Infant
Single Most Likely Diagnosis
- Gastroesophageal Reflux (GER): This is the most common cause of non-bilious emesis in infants, especially at this age. It occurs due to the immaturity of the lower esophageal sphincter, leading to the reflux of stomach contents into the esophagus.
Other Likely Diagnoses
- Infectious Gastroenteritis: Viral infections are common in infants and can cause non-bilious vomiting. However, the absence of fever and diarrhea might make this less likely.
- Overfeeding or Underfeeding: Incorrect feeding techniques or volumes can lead to vomiting in infants.
- Lactose Intolerance or Milk Protein Allergy: Although less common, these conditions can cause vomiting in infants, especially if they are formula-fed or if the mother consumes dairy products while breastfeeding.
- Pyloric Stenosis (early presentation): Although typically presents with bilious vomiting, early stages might not have bilious emesis.
Do Not Miss Diagnoses
- Intestinal Obstruction: Conditions like duodenal atresia or stenosis, and Hirschsprung's disease can present with non-bilious vomiting and are critical to diagnose early to prevent complications.
- Congenital Adrenal Hyperplasia: This condition can lead to vomiting due to salt wasting and is crucial to diagnose to prevent severe dehydration and electrolyte imbalances.
- Inborn Errors of Metabolism: Certain metabolic disorders can present with non-specific symptoms including vomiting and are critical to identify for appropriate management.
Rare Diagnoses
- Food Protein-Induced Enterocolitis Syndrome (FPIES): A rare condition that can cause vomiting, diarrhea, and abdominal distension after ingestion of specific food proteins.
- Eosinophilic Esophagitis: Although more common in older children, it can occur in infants and cause vomiting due to esophageal inflammation and eosinophilic infiltration.
- Congenital Anomalies of the Gastrointestinal Tract: Anomalies like esophageal webs or rings, and gastric duplications are rare but can cause non-bilious vomiting in infants.