Jaundice, at four ages

18 hours

Hemolysis: this is never physiological.

Differential

1. ABO or Rh incompatibility
2. G6PD deficiency
3. Sepsis
4. Hereditary spherocytosis

What changes

A bilirubin now, a blood group and direct antiglobulin test, a blood count and a reticulocyte count. Plot the bilirubin on the hour-specific nomogram; phototherapy thresholds are lower in the first day and in preterm or hemolysing infants.

4 days

Physiological or breastfeeding jaundice, and the bilirubin level that needs phototherapy.

Differential

1. Physiological jaundice
2. Breastfeeding jaundice (insufficient intake, weight loss)
3. Hemolysis, still
4. Cephalhematoma or bruising
5. Sepsis

What changes

Measure, do not estimate: visual assessment is unreliable, especially in darker skin. Weigh the baby, assess feeding and output, plot the level, and treat by the nomogram. Ask about a sibling who needed phototherapy.

3 weeks

Prolonged jaundice: is any of it conjugated? Biliary atresia has a surgical clock.

Differential

1. Breast milk jaundice (unconjugated, thriving, a diagnosis after the rest are excluded)
2. Biliary atresia (conjugated, pale stools, dark urine)
3. Hypothyroidism
4. Urinary tract infection
5. Neonatal hepatitis, metabolic disease

What changes

Jaundice beyond 14 days in a term infant needs a split bilirubin. A conjugated fraction that is raised is a liver problem; pale stools with dark urine is biliary atresia until an ultrasound and a hepatology review say otherwise, and the Kasai procedure works best before 60 days.

12 years

Hepatitis, hemolysis, and the drug or the autoimmune disease behind the liver.

Differential

1. Viral hepatitis (A, Epstein-Barr virus)
2. Drug-induced liver injury (acetaminophen, antibiotics, anticonvulsants)
3. Autoimmune hepatitis
4. Wilson disease
5. Hemolysis (sickle cell disease, spherocytosis)
6. Gilbert syndrome (mild, unconjugated, well)

What changes

Adult-style liver panel logic: hepatocellular versus cholestatic pattern, split bilirubin, a synthetic function check with the INR. Ask about acetaminophen and about supplements.