Biliary Atresia is the Most Likely Diagnosis
The combination of deep jaundice persisting at 2 months of age with pale (acholic) stools in an otherwise healthy-appearing, well-growing infant is pathognomonic for biliary atresia until proven otherwise. 1
Critical Diagnostic Features Present
The clinical presentation strongly indicates biliary atresia based on:
- Conjugated hyperbilirubinemia with acholic stools is the hallmark finding that distinguishes biliary atresia from other causes of neonatal cholestasis 1
- Jaundice persisting beyond 2-3 weeks with pale stools defines pathologic neonatal cholestasis requiring immediate intervention 1, 2
- The infant appearing healthy and growing well does not exclude biliary atresia—this is a common presentation that can mislead clinicians into false reassurance 3, 4
Why Other Options Are Less Likely
Neonatal Hepatitis (Option A)
- While neonatal hepatitis can cause cholestasis, it typically presents with more systemic illness and poor growth 5
- The specific combination of acholic stools with an otherwise thriving infant is more characteristic of biliary atresia 1
TORCH Infection (Option C)
- TORCH infections usually present with additional systemic findings such as hepatosplenomegaly, microcephaly, intrauterine growth restriction, or other congenital anomalies 5
- The infant's healthy appearance and normal growth make this less likely
Galactosemia (Option D)
- Galactosemia typically presents in the first days to weeks of life with vomiting, hepatomegaly, hypoglycemia, and failure to thrive once milk feeding begins 6
- A thriving, well-growing 2-month-old would be inconsistent with untreated galactosemia
Urgent Management Required
This infant requires immediate evaluation because biliary atresia is a surgical emergency:
- The Kasai portoenterostomy must be performed ideally before 60 days of age to maximize success and prevent the need for liver transplantation 1
- At 2 months (approximately 60 days), this infant is at the critical age threshold where surgical outcomes begin to decline rapidly 4
- Failure to treat biliary atresia results in hepatic fibrosis and death within the first year of life 3, 4
Immediate Diagnostic Workup
The following tests must be obtained urgently:
- Measure direct/conjugated bilirubin immediately—any conjugated bilirubin >1.0 mg/dL when total bilirubin ≤5 mg/dL requires urgent evaluation 1
- Hepatobiliary ultrasound to assess for gallbladder abnormalities and triangular cord sign 1, 3
- Hepatobiliary scintigraphy (HIDA scan) to evaluate bile excretion 1
- Liver biopsy for definitive diagnosis showing bile duct proliferation and portal fibrosis 1, 3
Critical Pitfall to Avoid
Normal ultrasound findings cannot rule out biliary atresia 4. Many clinicians are falsely reassured by normal imaging, but biliary atresia requires surgical exploration and intraoperative cholangiography for definitive diagnosis if clinical suspicion remains high 4, 5.