L2: Jaundice Flashcards
Def of Jaundice
Yellow discoloration of the skin and mucous membrane due to hyperbilirubinemia.
where is Jaundice Best observed?
in the sclera since elastin in the sclera binds bilirubin.
Sites of Jaundice
appears first in soft palate (frenulum of the tongue), sclera (2-2.5 mg/dl), then skin (7 mg/dl) and mucous membranes
what is the normal Bilirubin level?
Normal bilirubin level < 1 mg/dl
when does jaundice appear?
Jaundice > 2.5 mg/dl.
What is PseudoJaundice
hypercarotenemia, the skin may turn yellowish due to the presence of beta-carotene.
Sources of Bilirubin
- 85% from the breakdown of old RBCs-the normal RBC survives 120 days, so every day 1/120 of blood is turning over.
- 15% from other heme containing enzymes, cytochromes, myoglobin, and immature RBCs in the bone marrow.
Bilirubin Metabolism
Compare between Conjugated & Unconjugated Bilirubin in terms of:
- Solubility?
- Normal Site
- Filtration by Kidney?
Normal Bile Composition
Major causes of Jaundice
Pre-Hepatic Causes of Jaundice
Hepatic Causes of Jaundice
Post-Hepatic Causes of Jaundice
Causes of Recurrent jaundice
DDx of Jaundice
- Carotenemia
- Atabrine toxicity
- Diffuse Xanthomatosis
pathogenesis of Hemolytic jaundice