What is the term for the yellowness of the skin in jaundice?

The Yellowness of Skin in Jaundice is Called Icterus

The yellowness of the skin in jaundice is medically termed "icterus." 1 This term specifically refers to the yellow discoloration of the skin, mucous membranes, and eyes that occurs in jaundice due to hyperbilirubinemia.

Clinical Presentation of Icterus

Icterus manifests as:

• Yellow pigmentation of the skin, tissues, and body fluids
• Most easily observable in hairless parts of the body
• More readily visible in hairless or albino individuals 1
• Typically becomes clinically apparent when serum bilirubin levels exceed 2.5-3 mg/dL 2

Anatomical Progression of Icterus

The yellow discoloration in jaundice follows a characteristic pattern:

• First appears in the face
• Progresses caudally to the trunk and extremities 1
• Affects the sclera (whites of the eyes) and dermal (skin) tissues 1

Clinical Significance and Assessment

When assessing icterus:

• Visual estimation of bilirubin levels based solely on the degree of yellowness can lead to errors
• A low threshold should be used for measuring the total serum bilirubin (TSB) 1
• Noninvasive transcutaneous bilirubin (TcB) measurement devices can provide valid estimates of TSB levels, typically within 2-3 mg/dL of actual values 1
• TcB measurements are less reliable in patients undergoing phototherapy as the skin becomes "bleached" 1

Diagnostic Approach

When icterus is observed:

• Initial tests should include liver function tests with fractionated bilirubin, complete blood count with platelet count, liver enzymes, and abdominal ultrasound 3
• Urine testing for bilirubin can quickly indicate if conjugated hyperbilirubinemia is present 4
• Abdominal ultrasound is the initial imaging modality of choice with a sensitivity of 84.8% and specificity of 93.6% 3

Clinical Pitfalls to Avoid

1. Don't rely solely on visual assessment: The degree of yellowness doesn't precisely correlate with bilirubin levels 1

2. Don't confuse terms: While often used interchangeably, direct-reacting bilirubin is not the same as conjugated bilirubin 1

3. Don't delay treatment: Obtaining a venous sample to "confirm" an elevated capillary TSB level is not recommended as it will delay treatment initiation 1

4. Don't miss serious underlying causes: Icterus can indicate serious underlying disease of the liver or biliary tract and requires thorough evaluation 5

By recognizing icterus and understanding its significance, clinicians can promptly initiate appropriate diagnostic workup to identify and address the underlying cause of jaundice.