Paediatrics: Jaundice

2021-04-15 02:23 PM

Jaundice occurs when serum bilirubin >25–30mmol/L. It is rare outside the neonatal period.

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.