Paediatrics: Jaundice

Jaundice

Jaundice occurs when serum bilirubin >25–30mmol/L. It is rare outside 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);

• Abdominal US, abdominal CT/MRI, biliary scintigraphy, e.g. hepatoiminodiacetic acid [HIDA] scan).

• Liver biopsy.

Treatment

• Remove or treat 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.