Paediatrics: Jaundice

Jaundice

Jaundice occurs when serum bilirubin >25–30mmol/L. It is rare outside the neonatal period. First, determine the SBR and conjugated (direct) fraction. Unconjugated jaundice is rarely due to liver disease. Conjugated jaundice (>20mmol/L) is due to liver disease and requires investigation.

Unconjugated jaundice

Due to excess bilirubin production, impaired liver uptake, or conjugation. 

Causes

• Haemolysis (spherocytosis, G6PD deficiency, sickle cell anaemia, thalassaemia, HUS).
• Defective bilirubin conjugation (Gilbert syndrome, Crigler–Najjar syndrome).

Intrahepatic cholestasis

Here, jaundice is due to hepatocyte damage +/– cholestasis. There is un-conjugated +/– conjugated hyperbilirubinaemia.

Causes

Infectious

• Viral hepatitis, including chronic hepatitis.
• Bacterial hepatitis (leptospirosis [Weil’s disease], septicaemia, Mycoplasma, liver abscess).
• Toxoplasma gondii.

Toxic

• Drugs or poisons, e.g. paracetamol overdose, sodium valproate, anti-TB drugs, cytotoxic drugs.
• Fungi (Amanita phalloides).

Metabolic

• Galactosaemia, hereditary fructose intolerance.
• Tyrosinaemia type 1.
• Wilson’s disease.
• A₁-antitrypsin deficiency.
• Hypothyroidism.
• Peroxisomal disorders, e.g. Zellweger syndrome.
• Dubin–Johnson syndrome, Rotor syndrome.

Biliary hypoplasia

• Non-syndromic.
• Syndromic, e.g. Alagille syndrome.

Cardiovascular

• Budd–Chiari syndrome.
• Right heart failure.

Autoimmune hepatitis 

Autoimmune hepatitis.

Cholestatic (obstructive) jaundice

Conjugated hyperbilirubinaemia is due to bile tract obstruction.

Causes

• Biliary atresia.
• Choledochal cyst.
• Caroli’s disease.
• Primary sclerosing cholangitis (commonly associated with IBD).
• Cholelithiasis (may be secondary to chronic haemolysis).
• Cholecystitis.
• Cystic fibrosis.
• Obstructive tumours or cysts.

Management of jaundice

Full history 

e.g. medications, family history, overseas travel, past blood transfusions, jaundice contacts, pale stools, or dark urine (cholestasis).

Examination 

Vital signs; conscious level (hepatic coma); hepatic stigmata (= chronic liver disease); pallor (haemolysis); hepatomegaly; splenomegaly; ascites; peripheral oedema.

Investigations

Depending on which of the above pattern presents these may include:

• FBC, blood film, reticulocyte count.
• Coagulation studies.
• U&E, SBR (total and conjugated), LFT, albumin, total protein, TFT.
• Viral serology (hepatitis A, B, C, EBV, CMV), blood culture, leptospira and toxoplasma antibody titres.
• IEM screen, ammonia, copper studies (serum copper i, d, or n, serum caeruloplasmin ‘fall’ in Wilson’s disease), blood glucose, A₁-antitrypsin level, galactose-1-uridyl-phosphatase level.
• Immunoglobulins, anti-nuclear antibody, smooth muscle and liver/ kidney antibodies (autoimmune hepatitis);
• The abdominal US, abdominal CT/MRI, biliary scintigraphy, e.g. hepatoiminodiacetic acid [HIDA] scan).
• Liver biopsy.

Treatment

• Remove or treat the underlying cause.
• Correct blood glucose if it is low.
• Correct any clotting abnormalities.
• Phototherapy may be helpful only if jaundice has a significant unconjugated component, e.g. Crigler–Najjar syndrome
• Treat any associated anaemia if due to haemolysis.
• Treat liver failure as appropriate.