Differential Diagnosis for Vomiting in a 2-Month-Old in the Emergency Department

Single Most Likely Diagnosis

• Gastroesophageal Reflux Disease (GERD): This is a common condition in infants, characterized by the backflow of stomach contents into the esophagus, leading to vomiting. It's often seen in this age group due to the immaturity of the lower esophageal sphincter.

Other Likely Diagnoses

• Viral Gastroenteritis: Common in infants, this condition is caused by viruses that lead to inflammation of the stomach and intestines, resulting in vomiting, diarrhea, and sometimes fever.
• Overfeeding or Underfeeding: Incorrect feeding techniques or volumes can lead to vomiting in infants.
• Infection (e.g., Urinary Tract Infection, Pneumonia): Infections can cause nonspecific symptoms in infants, including vomiting.
• Food Allergy or Intolerance: Allergic reactions to formula or breast milk components can cause vomiting.

Do Not Miss Diagnoses

• Pyloric Stenosis: A condition where the pylorus (the passage between the stomach and small intestine) thickens, blocking food from entering the intestine, leading to projectile vomiting. It's crucial to diagnose early to prevent dehydration and electrolyte imbalances.
• Intussusception: A condition where a part of the intestine slides into an adjacent part, potentially cutting off blood supply. It's a surgical emergency and can present with vomiting, abdominal pain, and bloody stools.
• Volvolus or Intestinal Obstruction: Twisting of the intestine or blockage can lead to severe vomiting, abdominal distension, and can be life-threatening if not promptly treated.
• Congenital Heart Disease: Severe cases can lead to feeding difficulties and vomiting due to heart failure.
• Inborn Errors of Metabolism: Certain metabolic disorders can present with vomiting, among other symptoms, and require early diagnosis for proper management.

Rare Diagnoses

• Congenital Anomalies of the Gastrointestinal Tract: Conditions like esophageal atresia, tracheoesophageal fistula, or duodenal atresia can cause vomiting and are usually diagnosed shortly after birth but may occasionally present later.
• Neonatal Abstinence Syndrome: Infants born to mothers with substance use disorders can experience withdrawal symptoms, including vomiting.
• Adrenal Insufficiency: Rare conditions like congenital adrenal hyperplasia can lead to vomiting among other symptoms due to hormonal imbalances.