ittero

Ittero, also known as jaundice, is the yellowing of the skin, sclerae, and mucous membranes caused by elevated levels of bilirubin in the blood. It is a sign rather than a disease, indicating an underlying condition that affects bilirubin production, processing, or excretion. Bilirubin can be unconjugated or conjugated; the ratio of direct (conjugated) to indirect (unconjugated) bilirubin helps identify the probable cause.

Causes are commonly categorized as prehepatic (increased bilirubin from hemolysis or ineffective erythropoiesis), hepatic (liver cell injury from hepatitis, cirrhosis, or drugs), and posthepatic (obstruction of bile ducts from gallstones, tumors, or strictures). Newborns often develop physiological jaundice due to immature bilirubin metabolism.

Clinical features include yellowing of the skin and sclerae, dark urine, pale stools, and sometimes itching. Symptoms related to the underlying condition, such as fatigue, abdominal pain, fever, or weight loss, may be present. Diagnosis relies on history and examination, measurements of total and direct bilirubin, liver function tests, and imaging studies if obstruction is suspected; neonatal assessment may involve transcutaneous bilirubin measurements and close monitoring to prevent kernicterus.

Management targets the underlying cause. Prehepatic jaundice requires addressing hemolysis; hepatic jaundice involves treating the liver disease; posthepatic jaundice aims to relieve biliary obstruction. In newborns, phototherapy or exchange transfusion may be used for severe hyperbilirubinemia.

Prognosis varies with cause and severity; some forms resolve with treatment, while persistent jaundice can indicate chronic liver disease or ongoing obstruction.