Polycythemia Vera Symptoms
Polycythemia vera presents with a characteristic constellation of symptoms including aquagenic pruritus (itching after bathing), erythromelalgia (burning pain in hands/feet), microvascular disturbances (headache, visual changes, lightheadedness), splenomegaly, and constitutional symptoms, alongside laboratory findings of elevated hematocrit, thrombocytosis, and leukocytosis. 1
Primary Clinical Manifestations
Microvascular Disturbances
These result from platelet-endothelial interactions causing transient occlusive phenomena and include 1:
- Headache and lightheadedness
- Transient neurologic or ocular disturbances (visual changes occur in 14% of patients) 2
- Tinnitus
- Atypical chest discomfort
- Paresthesias
Erythromelalgia
This highly characteristic symptom occurs in approximately 3-5.3% of PV patients 1, 2. It manifests as:
- Painful, burning sensation in feet or hands
- Associated erythema and warmth
- Responds promptly (within hours) to low-dose aspirin (81 mg/day) 1
The pathogenesis involves platelet-mediated endothelial injury with transient thrombotic occlusion by platelet aggregates 1.
Aquagenic Pruritus
This is one of the most debilitating symptoms 1:
- Occurs in 33-48% of patients either at diagnosis or later 1, 2
- Characteristically exacerbated by hot baths or showers 1
- May cause sleep deprivation and interference with social/physical activities 1
- Can be the most agonizing aspect of the disease 1
Splenomegaly
Constitutional Symptoms
Patients commonly experience 3, 4:
- Fatigue
- Bone pain
- Night sweats
- Weight loss
Laboratory and Hematologic Features
Blood Count Abnormalities
The diagnostic hallmark is erythrocytosis, but other cytopenias are common 1:
- Elevated hemoglobin/hematocrit (required for diagnosis: >16.5 g/dL in men, >16.0 g/dL in women) 2
- Thrombocytosis in 53% of patients 2
- Leukocytosis in 49% of patients 2
- Microcytosis from iron deficiency (may occur due to repeated phlebotomy or occult bleeding) 1
PV-Related Features That Should Prompt Diagnostic Consideration
The diagnosis should be suspected when any of these features accompany borderline-high hematocrit 1:
- Thrombocytosis
- Leukocytosis
- Microcytosis from iron deficiency
- Splenomegaly
- Aquagenic pruritus
- Unusual thrombosis including Budd-Chiari syndrome 1
- Erythromelalgia
Thrombotic and Hemorrhagic Complications
Thrombosis Risk
PV carries significant thrombotic risk 2, 3:
- Arterial thrombosis occurs in 16% prior to or at diagnosis 2
- Venous thrombotic events in 7% 2
- Venous thrombosis can involve unusual sites, particularly splanchnic veins 2
- 20-year thrombosis risk approximately 26% 3
Bleeding Risk
- Increased bleeding risk, especially with extreme thrombocytosis (platelet count ≥1000 × 10⁹/L) 2
- Acquired von Willebrand disease can occur with extreme thrombocytosis 2
Important Clinical Pitfalls
Diagnostic Considerations
- Iron deficiency can mask the diagnosis by lowering hemoglobin/hematocrit into the normal range despite underlying PV 1
- Documented increase in hemoglobin/hematocrit above baseline for an individual patient warrants investigation, even if values remain within the reference range 1
- Comorbid conditions causing hypoxia (e.g., chronic lung disease) can coexist with PV and complicate diagnosis 1
Symptom Management Nuances
- Pruritus treatment is challenging: antihistamines have unpredictable responses; paroxetine (selective serotonin reuptake inhibitor) shows >80% response rate 1; interferon-α reduces pruritus in up to 81% of patients 1
- Iron replacement for pruritus is discouraged despite some correlation with iron deficiency, as it has not been consistently effective 1
- Erythromelalgia requires aspirin as first-line, but cytoreductive therapy may be necessary if aspirin fails 1