Differential Diagnosis for Vomiting in a 5-Month-Old
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. The age of the infant and the nature of the vomiting (often after feeding) make GERD a likely diagnosis.
Other Likely Diagnoses
- Viral gastroenteritis: This is a common cause of vomiting in infants, often accompanied by diarrhea and fever. The highly contagious nature of viral gastroenteritis and the exposure history of the infant can support this diagnosis.
- Overfeeding or feeding intolerance: Infants who are fed too much or have difficulty digesting certain formulas may vomit. This diagnosis is considered based on the feeding history and the pattern of vomiting.
- Food allergy or intolerance: Allergies to proteins in formula (like cow's milk) or introduced foods can cause vomiting. A history of introducing new foods or formulas around the time of symptom onset supports this diagnosis.
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. Although less common, missing this diagnosis can lead to severe 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 medical emergency that can cause vomiting, abdominal pain, and bloody stools.
- Infections (e.g., urinary tract infections, meningitis): While less common causes of vomiting, infections can be life-threatening and require immediate attention. Fever, lethargy, or signs of distress would support considering these diagnoses.
Rare Diagnoses
- Metabolic disorders: Certain metabolic conditions can cause vomiting in infants, such as congenital adrenal hyperplasia or disorders of amino acid metabolism. These are rare but critical to diagnose early for proper management.
- Congenital anatomical abnormalities: Conditions like esophageal atresia or tracheoesophageal fistula, though usually diagnosed in the neonatal period, could potentially present later with vomiting if less severe.
- Increased intracranial pressure: Conditions affecting the brain, such as hydrocephalus or brain tumors, can cause vomiting. These are rare in infants but would be critical to identify due to their serious nature.