Differential Diagnosis for the 5-Day-Old Neonate
The clinical presentation of this neonate suggests a cardiovascular issue, given the symptoms of poor feeding, sweating, pallor, respiratory distress exacerbated by feedings, and the physical examination findings. Here's a categorized differential diagnosis:
Single Most Likely Diagnosis
- Coarctation of the Aorta: This condition is characterized by a narrowing of the aortic isthmus, leading to increased left ventricular afterload, which matches the clinical presentation. The weak femoral pulses compared to strong brachial pulses, along with the other symptoms, strongly suggest this diagnosis. The presence of a gallop and the liver edge being palpable 3 cm below the right costal margin indicate cardiac dysfunction and possible congestive heart failure.
Other Likely Diagnoses
- Hypoplastic Left Heart Syndrome (HLHS): Although less likely given the specific pattern of pulse strengths, HLHS could present with similar symptoms of heart failure and differential pulses. However, it typically involves more severe left-sided obstruction and might present with more pronounced cyanosis.
- Interrupted Aortic Arch: This is another form of left ventricular outflow obstruction that could present similarly to coarctation, with differential blood pressures in the arms and legs. However, it's less common and might have additional associated anomalies.
- Severe Aortic Stenosis: This condition could also lead to increased left ventricular afterload and similar symptoms, but the presence of weak femoral pulses specifically points more towards an aortic obstruction like coarctation.
Do Not Miss Diagnoses
- Aortic Dissection or Rupture: Although extremely rare in neonates, any condition leading to a sudden onset of symptoms similar to those described, especially with a significant differential in pulse strength between upper and lower limbs, should prompt consideration of such catastrophic events.
- Cardiac Tamponade: While the presentation might not fully align, cardiac tamponade can cause cardiac dysfunction and could potentially lead to differential pulses if there's associated cardiac or aortic pathology. It's a condition that requires immediate recognition and treatment.
Rare Diagnoses
- Vascular Rings or Slings: These are congenital anomalies of the aortic arch that can cause respiratory and feeding difficulties due to compression of the trachea and esophagus. While they might not directly cause the cardiovascular symptoms described, they could be part of a complex congenital heart disease presentation.
- Takayasu Arteritis: An extremely rare condition in neonates, characterized by large vessel vasculitis, which could potentially cause differential pulses and systemic symptoms. However, it's much more common in older children and adults.