Conjunctival icterus is an indicator of elevated bilirubin levels (hyperbilirubinemia) due to an underlying disease that affects the metabolism or excretion of bilirubin. The eye conjunctiva is a thin layer that overlies the sclera. It is one of the very first tissues to change in color due to increasing bilirubin levels. In general, it is seen when bilirubin levels reach at least 2 to 4 mg/dL. The term scleral icterus is an incorrect term to describe this condition (misnomer) because this tissue has the least amount of bilirubin staining it.
Management and Disposition
Jaundice itself is not a disease, but rather a sign of many possible underlying diseases. Patients presenting to the ED with jaundice present a diagnostic opportunity to identify the etiology. The pathophysiologic mechanism can be categorized as prehepatic/hemolytic, hepatic/hepatocellular, and posthepatic/cholestatic based on physiologic mechanism. A typical liver panel or liver function tests, including aminotransferases (alanine aminotransferase, aspartate aminotransferase), alkaline phosphatase, bilirubin (which causes the jaundice), and protein levels (total and albumin), can aid in the diagnosis. In general, elevated levels are not harmful to adults. However, once at a certain level, bilirubin-induced brain dysfunction (kernicterus) can occur and is typically seen in newborn patients.
Conjunctival sclera is a sign, not a disease. Consider a range of etiologies when patients present to the ED.
Refer to this finding as conjunctival icterus, rather than scleral icterus (misnomer).
Conjunctival Icterus. Patient with yellow-tinged conjunctiva. (Photo contributor: Kevin J. Knoop, MD, MS.)