Ikterusta

Ikterusta, in English often referred to as jaundice, is a clinical sign characterized by yellowing of the skin, mucous membranes, and the sclerae due to elevated levels of bilirubin in the blood. It is not a disease itself but indicates an underlying condition affecting bilirubin production, processing, or excretion. Bilirubin exists in two main forms: unconjugated (indirect) and conjugated (direct). Disruption in bilirubin metabolism can lead to hyperbilirubinemia and visible icterus.

Causes of ikterusta are commonly categorized as prehepatic, hepatic, or posthepatic. Prehepatic causes include increased red blood cell breakdown and disorders such as hemolysis or Gilbert syndrome. Hepatic causes involve liver diseases such as hepatitis, cirrhosis, alcoholic liver disease, or drug-induced liver injury. Posthepatic causes result from obstruction of the bile ducts due to gallstones, tumors, or strictures. In newborns, physiologic jaundice arises from immature liver enzyme systems.

Clinical features include yellow discoloration of the skin and whites of the eyes, dark urine, pale stools, and sometimes itching. Additional symptoms depend on the underlying condition and may include fatigue, abdominal pain, fever, or weight loss. In newborns, extreme or rapidly rising bilirubin levels can risk kernicterus, a serious complication.

Diagnosis involves history, physical examination, and laboratory tests such as total and direct bilirubin, liver function tests (ALT, AST, ALP, GGT), and a complete blood count. Imaging (ultrasound, and sometimes MRI or CT) helps identify biliary obstruction or liver pathology.

Treatment targets the underlying cause. Mild or physiologic jaundice in newborns may require monitoring, while adults are treated with addressing liver disease, resolving obstructions, or adjusting medications. Prognosis depends on the underlying condition and timeliness of treatment.