Jaundice

This can be a symptom reported by the patient or a physical sign. It is confirmed by ↑bilirubin in the plasma. Yellow sclerae and skin usually becomes visible when serum bilirubin level is >35µmol/L, so urine tests may provide the first clue. First subdivide into the 5 leads below. Remember that haemolysis causes ↑urinary urobilinogen and ↓serum haptoglobin. Hepatic failure causes ↑serum unconjugated bilirubin but intrahepatic or extra hepatic biliary obstruction results in ↑serum conjugated bilirubin.

Some differential diagnoses and typical outline evidence

Carotinaemia	Suggested by: onset over months. Skin yellow with white sclerae, normal stools and normal urine. Diet rich in yellow vegetables/fruits).
	Confirmed by: no bilirubin, no urobilinogen in the urine and normal serum bilirubin. Normal liver function tests. Response to diet change.
‘Pre-hepatic’ jaundice due to haemolysis	Suggested by: jaundice and anaemia (the combination seen as ‘lemon’ or pale yellow). Normal dark stools and normal looking urine.
	Confirmed by: ↑ (unconjugated and thus insoluble) serum bilirubin but normal (conjugated and soluble) bilirubin and thus no ↑bilirubin in urine. ↑urobilinogen in urine and ↓serum haptoglobin. Normal liver function tests. ↑Reticulocyte count, Hb↓.
	Management: OHCM pp222–3.
‘Hepatic’ jaundice due to congenital enzyme defect	Suggested by: Normal looking stools and normal looking urine.
	Confirmed by: ↑serum bilirubin (unconjugated), but no (conjugated) bilirubin in urine. No urobilinogen in urine and normal haptoglobin. Normal liver function tests.
	Management: OHCM pp222–3.
‘Hepatocellular’ jaundice (‘hepatic’ with element of ‘obstructive’ jaundice)	Suggested by: onset of jaundice over days or weeks, stools pale or normal but dark urine.
	Confirmed by: ↑serum (conjugated) bilirubin and thus ↑urine bilirubin. Normal urine urobilinogen. Liver function tests all abnormal esp. ↑(ALT.
	Management: OHCM pp222–3.
‘Obstructive’ jaundice	Suggested by: onset of jaundice over days or weeks with pale stools and dark urine. Bilirubin ↑ (i.e. conjugated and thus soluble) in urine.
	Confirmed by: ↑serum conjugated bilirubin and thus ↑ urine bilirubin but no ↑urobilinogen in urine. Markedly (↑↑) alkaline phosphatase, but less abnormal liver function tests and ↑↑GT.
	Management: OHCM p484.