Chorea, Pruritus and Polycythemia: Looking for Clues

Chorea is a movement disorder usually due to vascular, hereditary, metabolic or drug-induced causes, and has rarely been reported in association with polycythemia vera (PV). Polycythemic chorea is an uncommon clinical entity that occurs more often in elderly women. PV is a treatable cause of chorea and must be considered during the diagnostic approach. We report the case of a 75-year-old woman with involuntary movements of the mouth and face with subsequent involvement of the trunk and limbs who was admitted for investigation of the chorea. The patient had the haematological attributes of PV and a positive mutation in the janus kinase 2 (JAK2) gene, and was therefore treated with hydroxyurea which led to a marked reduction in the chorea and improvement in haematological parameters. Various aetiologies of chorea must be considered in the elderly. The present case illustrates the importance of considering PV in the differential diagnosis, since its treatment leads to chorea resolution, thus avoiding serious complications. LEARNING POINTS: Polycythemia vera is a sporadic myeloproliferative disorder of the haematopoietic stem cells and is a treatable cause of chorea. Chorea is a movement disorder with various aetiologies that is difficult to diagnose. Prompt treatment of polycythemia vera will lead to resolution of the chorea, with aspirin and phlebotomy being recommended in low-risk cases and hydroxyurea in high-risk cases.