What is paresthesia in a patient with Polycythemia Vera (PV)?

What is Paresthesia in Polycythemia Vera?

Paresthesia in polycythemia vera is an abnormal tingling, numbness, or "pins and needles" sensation that represents a microvascular disturbance caused by platelet-mediated endothelial inflammation and transient thrombotic occlusion of small blood vessels. 1

Pathophysiology

• Paresthesias occur as part of a spectrum of microvascular complications in PV resulting from clonal platelet interaction with arteriolar endothelium, leading to inflammation-based transient occlusive phenomena. 1, 2

• The underlying mechanism involves platelet-mediated endothelial cell injury that produces inflammation and transient thrombotic occlusion by platelet aggregates in small vessels. 1

• These symptoms are distinct from major arterial or venous thrombotic events and represent a different category of vascular complications specific to myeloproliferative disorders. 3

Clinical Context and Associated Symptoms

• Paresthesias typically occur alongside other microvascular disturbances including headache, light-headedness, transient neurologic or ocular disturbances, tinnitus, and atypical chest discomfort. 1, 2

• Neurologic problems occur in 50-80% of patients with polycythemia vera, with some symptoms related to hyperviscosity and others to the associated coagulopathy. 4

• Erythromelalgia (painful burning sensation of hands or feet with erythema and warmth) is the most characteristic microvascular complication, occurring in approximately 3-5.3% of patients. 2, 5

Treatment Approach

• Low-dose aspirin (81 mg daily) produces prompt alleviation of paresthesias and other microvascular symptoms within hours in most patients with PV. 1, 2

• All patients with PV should receive once-daily or twice-daily aspirin (81 mg) in the absence of contraindications, as this is the backbone of treatment for preventing microvascular complications. 6, 7

• Phlebotomy alone does not prevent aspirin-responsive microcirculatory disturbances like paresthesias because thrombocythemia (platelet count >400 × 10⁹/L) persists despite hematocrit control. 3

When Additional Therapy is Needed

• Patients who do not respond adequately to aspirin may require cytoreductive therapy to normalize platelet counts. 1

• The risk of microvascular complications is best controlled by maintaining hematocrit below 45% AND platelet count below 400 × 10⁹/L. 3

• Hydroxyurea or interferon-α can be used for selective reduction of platelet count when aspirin alone is insufficient. 3, 7

Important Clinical Pitfall

• Do not dismiss paresthesias as benign neuropathy—in PV patients, these symptoms indicate active microvascular disease requiring treatment optimization with aspirin and potentially cytoreductive therapy to prevent progression to major thrombotic events. 1, 3