Causes of direct (conjugated) hyperbilirubinemia:
also see Evaluation of Neonatal Cholestatis, Management of Chronic Cholestasis

• Mnemonic: A yellow MAOIST. (oops, politically incorrect) or a more loving one: SI Te AMO
• disorders of bilirubin secretion:
  • Dubin-Johnson
  • Rotor syndromes (defect in transfer of bilirubin and other organic anions from liver to bile)
• mechanical obstruction (obstructive jaundice): a decrease in bile flow due to obstruction or absence of bile ducts
  • Intrahepatic: Alagille Syndrome characterized by paucity of intrahepatic bile ducts, anomalies of great vessels, vertebral anomalies, “elfin facies”
  • Extrahepatic biliary atresia
  • Choledochal cyst -congenital dilation and obstruction of common bile duct.
• Infection:
  • Hepatitis: HepB, HepA, Hepatitis non-A/non-B, Hepatitis delta, Neonatal giant cell hepatitis
  • TORCH
  • extrahepatic obstruction: Mycobacterial, atypical in an immunocompromised host
  • bacterial sepsis
• metabolic disorders: galactosemia, tyrosinemia, cystic fibrosis, alpha-1-antitrypsin deficiency, herditary fructose intolerance, Niemann-Pick disease, Wilson’s disease, hemochromatosis
• Toxic: hyperalimentation (prolonged TPN), erythromycin, phenytoin, acetaminophen, rifampin, halothane
• Autoimmune cholestatic jaundice, Cholangitis, sclerosing