4th June 2025

Skin manifestations of polycythaemia

The skin manifestations of polycythaemia are due to the increased red cell volume of the blood (and hence increased circulating blood volume) and hyperviscosity of the blood.

• Plethoric complexion
  • As polycythaemia progresses, the venules and capillaries in the skin must distend to accommodate the increase in blood volume
  • Leads to a ruddy and plethoric complexion 
  • The face, palms, earlobes and mucous membranes of the eyes are frequently affected.
• Aquagenic pruritus 
  • Itchy skin triggered by water contact – is another skin manifestation of polycythaemia. 
  • Cause unknown but multiple underlying mechanisms have been suggested – such as the release of inflammatory mediators from mast cell degranulation or platelet aggregation.
• Erythromelalgia 
  • Condition that produces intermittent attacks of redness and a burning pain of the feet and hands. 
  • It can be a primary condition in itself, or secondary to haematological disorders such as polycythaemia. 
  • When associated with polycythaemia, it is thought that increased platelet activation causes the formation of thrombi in arterioles within the distal extremities; this results in tissue hypoxia and pain.
• Livedo reticularis describes 
  • A net-like (or reticular) skin discolouration, with purplish rings surrounding a paler centre. 
  • Results from impaired blood flow to the skin; in polycythaemia, this is due to the viscous blood flowing sluggishly through the blood vessels in the skin.