- Inspecting the patient's skin for evidence of pallor, plethora or jaundice provide information regarding the presence of anaemia, polycythaemia or haemolysis.
- Skin pallor is a sign of anaemia.
- General inspection of the patient may provide some clue regarding pallor, though it is more significant to assess pallor of the nail beds, palmar creases and conjunctivae.
Causes of Pallor
- Physiologicaly pale skin
- Chronic disease
- Low cardiac output, due to cardiac disease
- Peripheral shutdown, due to increased sympathetic activity
- Plethora is a change of appearance in the skin due to increased blood flow.
- Red discolouration, especially of the face.
Causes of Plethora
- Cushing’s syndrome
- Polycythaemia rubra vera
- In the context of the haematology examination, jaundice may be an indicator of haemolytic anaemia.
- Yellow discolouration of the skin and mucous membranes, due to deposition of bilirubin.
Causes of Jaundice
- Erythrocyte defects - sickle cell anaemia, thalassaemia, folate deficiency, pernicious anaemia, iron deficiency anaemia, sideroblastic anaemia, spherocytosis, lead poisoning
- Excessive erythrocyte destruction - haemolytic anaemia, thermal injury, envenomation, DIC, haemodialysis, breast milk jaundice
- Dysfunctional uptake - drugs
- Dysfunctional conjugation - Crigler-Najar, Gilbert’s disease
- Dysfunctional bilirubin storage / excretion - Dubin-Johnson
- Hepatocyte damage - cirrhosis, hepatitis, tuberculosis, EBV, CMV, varicella, drug-induced hepatitis, autoimmunity, alpha-1 antitrypsin deficiency, Wilson’s disease
- Intrahepatic cholestasis - drugs, pregnancy, cystic liver disease, sepsis, total parenteral nutrition, Hodgkin’s disease, biliary cirrhosis, sclerosing cholangitis, liver cancer (primary / metastatic)
- Extrahepatic cholestasis - cholangitis, cholelithiasis, pancreatitis, tumours (eg. pancreatic), bile duct (stenosis or extrinsic compression)