Summary
Definition
History and exam
Key diagnostic factors
- erythromelalgia
- splenomegaly
- arterial and venous thrombosis
- bleeding
- livedo reticularis
Other diagnostic factors
- age 50 to 70 years
- female sex
- no symptoms
- headache
- dizziness, lightheadedness, and paraesthesias
- syncope and seizures
- transient visual disturbances
- hepatomegaly
- priapism
Risk factors
- Unknown risk factors
- Genetic mutations (e.g., JAK2, CALR, or MPL)
Diagnostic investigations
1st investigations to order
- FBC with peripheral smear
- iron panel
Investigations to consider
- CRP
- ESR
- fibrinogen
- bone marrow biopsy and histopathology
- Janus kinase 2 (JAK2) mutation testing of peripheral blood
- myeloproliferative leukaemia virus oncogene (MPL) mutation testing of peripheral blood
- calreticulin (CALR) mutation testing of peripheral blood
- BCR-ABL fluorescent in situ hybridisation (FISH) of bone marrow
Treatment algorithm
thrombosis or bleeding
non-pregnant: very low-, low-, or intermediate-risk
non-pregnant: high risk
pregnant: very low- or low-risk
pregnant: intermediate-risk
pregnant: high-risk
Contributors
Authors
Debabrata Mukherjee, MD, FACC

Chairman, Department of Internal Medicine
Chief, Cardiovascular Medicine
Professor of Internal Medicine
Texas Tech University Health Sciences Center at El Paso
El Paso
TX
Disclosures
DM declares that he has no competing interests.
Peer reviewers
Tony Kan, MD
Senior Staff Physician
Henry Ford Medical Center
Sterling Heights
MI
Disclosures
TK declares that he has no competing interests.
Uri Rozovski, MD
Department of Cardiology
Tel Aviv Sourasky Medical Center
Tel Aviv
Israel
Disclosures
UR declares that he has no competing interests.
David A. Garcia, MD
Professor
Division of Hematology
University of Washington Seattle
WA
Disclosures
DAG declares that he has no competing interests.
Bethany Samuelson, MD
Fellow
Division of Hematology
University of Washington
Seattle
WA
Disclosures
BS declares that she has no competing interests.
Differentials
- Secondary (reactive) thrombocytosis
- Spurious thrombocytosis
- Familial essential thrombocythaemia
More DifferentialsGuidelines
- Unmet clinical needs in the management of CALR-mutated essential thrombocythaemia: a consensus-based proposal from the European LeukemiaNet
- Essential thrombocythemia treatment algorithm 2018
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