Differential Diagnosis for a 4-week-old Boy with Vomiting
- Single most likely diagnosis:
- Gastroesophageal reflux disease (GERD): The patient's symptoms of small spit-ups after most feeds since birth, which improved with reflux precautions, and the recent increase in forceful emesis after every feed, are consistent with GERD. The fact that the emesis looks like formula and the patient continues to feed frequently suggests that the vomiting is not causing significant distress or obstruction.
- Other Likely diagnoses:
- Pyloric stenosis: The patient's increasingly forceful emesis after every feed, despite feeding frequently, could be indicative of pyloric stenosis. However, the absence of a palpable "olive" mass in the abdomen and the fact that the patient's weight has not decreased significantly make this diagnosis less likely.
- Overfeeding or feeding intolerance: The patient's frequent feeding and immediate feeding after vomiting could be contributing to the vomiting. This, combined with the fact that the patient's weight has not changed in two weeks, suggests that the patient may be experiencing feeding intolerance.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Intestinal obstruction: Although the patient's abdomen is soft and nontender, the possibility of an intestinal obstruction, such as a duodenal atresia or stenosis, or an intestinal volvulus, must be considered. The patient's infrequent stools could be a sign of an underlying obstruction.
- Inborn error of metabolism: Certain metabolic disorders, such as urea cycle defects or organic acidemias, can present with vomiting in the neonatal period. Although these conditions are rare, they can be life-threatening if not diagnosed promptly.
- Infectious causes (e.g., urinary tract infection, sepsis): Infections can cause vomiting in infants, and it is essential to consider these possibilities, especially if the patient shows signs of distress, fever, or other symptoms.
- Rare diagnoses:
- Gastrointestinal duplications or other congenital anomalies: These rare conditions can cause vomiting in infants and may require surgical intervention.
- Food protein-induced enteropathy: This condition is a rare cause of vomiting in infants and is often associated with an allergy to cow's milk protein. However, the patient's symptoms do not strongly suggest this diagnosis, and other causes are more likely.