Differential Diagnosis for Neonatal Jaundice
Single Most Likely Diagnosis
- Breast Milk Jaundice: This condition is likely given the patient's exclusive breastfeeding, good latch, and family history of siblings requiring phototherapy. Breast milk jaundice typically presents in the first week of life, with a peak around 3-7 days, and is associated with elevated unconjugated bilirubin levels, as seen in this patient.
Other Likely Diagnoses
- Physiological Jaundice: This is a common condition in newborns, especially in the first few days of life, characterized by elevated unconjugated bilirubin due to the breakdown of red blood cells and the liver's initial inability to conjugate bilirubin efficiently. The patient's age and laboratory results are consistent with this diagnosis.
- Hemolysis due to ABO Incompatibility: Although the maternal blood group is AB, Rh D-positive, and there's no mention of the baby's blood type, ABO incompatibility can still occur and cause hemolysis leading to jaundice. However, the peripheral smear is normal, which makes this less likely.
Do Not Miss Diagnoses
- Biliary Atresia: Although rare, biliary atresia is a serious condition that requires prompt diagnosis and treatment to prevent liver damage. It typically presents with conjugated hyperbilirubinemia, but early in the disease, unconjugated bilirubin may also be elevated. The presence of any conjugated bilirubin (0.4 mg/dL in this case) warrants consideration of this diagnosis.
- Infection (e.g., Sepsis): Infections can cause jaundice in newborns and are critical to identify due to their potential severity. The patient's vital signs are normal, and the Group B streptococcus screen was negative, but other infections could still be present.
- Hemolytic Disease of the Newborn (HDN) due to Rh or Other Blood Group Incompatibilities: Despite the maternal Rh D-positive status, other blood group incompatibilities or issues could lead to hemolysis. The normal hematocrit and peripheral smear make this less likely, but it remains a critical diagnosis not to miss.
Rare Diagnoses
- Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency: This condition can cause hemolysis and jaundice, especially in response to certain medications or infections. It's more common in certain ethnic groups, including Asian populations.
- Crigler-Najjar Syndrome: A rare genetic disorder affecting the enzyme responsible for bilirubin conjugation, leading to severe unconjugated hyperbilirubinemia.
- Congenital Thyroid Disorders: Hypothyroidism can cause jaundice in newborns, although it's less common and typically associated with other signs of hypothyroidism.