Jaundice is often apparent (in white people) when the serum bilirubin level exceeds 35micromol/l. Jaundice is the result of interference in the normal metabolism of bilirubin from the breakdown of haemoglobin.
This could mean a problem with the uptake of bilirubin, the transport, the conjugation in the liver or the excretion - or a combination of all of them.
Onset of jaundiceThe patient may complain of a generalised itch (possibly days before the jaundice becomes otherwise clinically obvious), change in colour of stools and urine (especially in obstructive jaundice or viral hepatitis), fatigue, or flu-like symptoms (suggesting hepatitis).
A travel history is important. The incubation of hepatitis can vary: 15-50 days for hepatitis A and 45-180 days for hepatitis B; also consider malaria.
|Red flag symtoms|
Also enquire about blood transfusions, IV drug and alcohol abuse, tattoos and piercings, and occupational history (sewage workers, exposure to chemicals). Is the patient pregnant (think cholestasis or pre-eclampsia)?
Check recent and currently prescribed medication as well as non-prescription drugs. Typical medicines that can cause jaundice include antibiotics, some analgesia, amitriptyline, furosemide or hormone preparations (including the contraceptive pill).
Enquire about previous episodes of hepatitis, liver disease, or any known family history of jaundice (Gilbert's syndrome affects up to 5 per cent of the population). Also consider thalassaemia and other blood conditions. Ask about diet, as people with an excessive intake of beta-carotene may look generally orange/yellow - but the sclera stays white.
The speed of onset of jaundice can be important. Acute abdominal pain with rapidly developing jaundice typically suggests symptomatic gallstones. On the other hand, gradually developing and painless jaundice suggests carcinoma (typically bowel or breast cancer) until proven otherwise.
It can be difficult to see jaundice in darker-skinned patients. Look for other liver stigmata on the skin, organomegaly (liver, spleen and pancreas), generalised oedema or ascites.
Check a urine dipstick and blood tests; FBC including ferritin (for haemochromatosis), inflammatory markers, clotting, and LFTs. Note that alkaline phosphatase (AP) is increased especially with extra- or intrahepatic biliary disease; a higher alanine transaminase (ALT) than aspartate aminotransferase (AST) is typical for acute hepatitis or obstructive jaundice.
Although sensitive, gamma-glutamyl transpeptidase (GGT) is not specific for alcohol intake. Add hepatitis serology if needed. Consider an autoimmune screen (up to 20 per cent of chronic hepatitis is due to autoimmune disorders).
Unless you can be confident that you are dealing with a non-urgent diagnosis (gallstones or Gilbert's syndrome) the patient may need an admission or at least an early referral for further investigations.
- Dr Jacobi is a salaried GP in York