==[[Polycythemia vera history and symptoms|History & Symptoms]]==
==[[Polycythemia vera history and symptoms|History & Symptoms]]==
Patients with polycythemia vera are often [[asymptomatic]]. A classic symptom of polycythemia vera is [[pruritis|generalized itching]], particularly after exposure to warm water, which may be due to abnormal [[histamine]] release<ref>{{cite journal | author = Steinman H, Kobza-Black A, Lotti T, Brunetti L, Panconesi E, Greaves M | title = Polycythaemia rubra vera and water-induced pruritus: blood histamine levels and cutaneous fibrinolytic activity before and after water challenge. | journal = Br J Dermatol | volume = 116 | issue = 3 | pages = 329-33 | year = 1987 | id = PMID 3567071}}</ref><ref>{{cite journal | author = Jackson N, Burt D, Crocker J, Boughton B | title = Skin mast cells in polycythaemia vera: relationship to the pathogenesis and treatment of pruritus. | journal = Br J Dermatol | volume = 116 | issue = 1 | pages = 21-9 | year = 1987 | id = PMID 3814512}}</ref> or [[prostaglandin]] production.<ref>{{cite journal | author = Fjellner B, Hägermark O | title = Pruritus in polycythemia vera: treatment with aspirin and possibility of platelet involvement. | journal = Acta Derm Venereol | volume = 59 | issue = 6 | pages = 505-12 | year = 1979 | id = PMID 94209}}</ref> Such itching is present in approximately 40% of patients with polycythemia vera.<ref name="pvsg"/> [[Gout|Gouty arthritis]] may be present in up to 20% of patients.<ref name="pvsg"/> [[Peptic ulcer disease]] is also common in patients with polycythemia vera; the reasons for this are unclear, but may be related to an increased susceptibility to infection with the ulcer-causing bacterium ''[[Helicobacter pylori|H. pylori]]''.<ref>{{cite journal | author = Torgano G, Mandelli C, Massaro P, Abbiati C, Ponzetto A, Bertinieri G, Bogetto S, Terruzzi E, de Franchis R | title = Gastroduodenal lesions in polycythaemia vera: frequency and role of Helicobacter pylori. | journal = Br J Haematol | volume = 117 | issue = 1 | pages = 198-202 | year = 2002 | id = PMID 11918555}}</ref>
A rare but classic symptom of polycythemia vera (and the related myeloproliferative disease [[essential thrombocythemia]]) is [[erythromelalgia]].<ref>{{cite journal | author = van Genderen P, Michiels J | title = Erythromelalgia: a pathognomonic microvascular thrombotic complication in essential thrombocythemia and polycythemia vera. | journal = Semin Thromb Hemost | volume = 23 | issue = 4 | pages = 357-63 | year = 1997 | id = PMID 9263352}}</ref> This is a sudden, severe burning pain in the hands or feet, usually accompanied by a reddish or [[cyanosis|bluish]] coloration of the skin. Erythromelalgia is caused by an increased platelet count or increased platelet "stickiness", resulting in the formation of tiny blood clots in the vessels of the extremity; it responds rapidly to treatment with [[aspirin]].<ref>{{cite journal | author = Michiels J | title = Erythromelalgia and vascular complications in polycythemia vera. | journal = Semin Thromb Hemost | volume = 23 | issue = 5 | pages = 441-54 | year = 1997 | id = PMID 9387203}}</ref><ref>{{cite journal | author = Landolfi R, Ciabattoni G, Patrignani P, Castellana M, Pogliani E, Bizzi B, Patrono C | title = Increased thromboxane biosynthesis in patients with polycythemia vera: evidence for aspirin-suppressible platelet activation in vivo. | journal = Blood | volume = 80 | issue = 8 | pages = 1965-71 | year = 1992 | id = PMID 1327286}}</ref>
Patients with polycythemia vera are prone to the development of blood clots ([[thrombosis]]). A major thrombotic complication (e.g. [[myocardial infarction|heart attack]], [[stroke]], [[deep venous thrombosis]], or [[Budd-Chiari syndrome]]) may sometimes be the first symptom or indication that a person has polycythemia vera.
Polycythemia vera occurs in all age groups (including children),[1] although the incidence increases with age. One study found the median age at diagnosis to be 60 years,[2] while a study in Olmsted County, Minnesota found that the highest incidence was in people aged 70–79 years.[3] The overall incidence in the Minnesota population was 1.9 per 100,000 person-years, and the disease was more common in men than women.[3]
↑Passamonti F, Malabarba L, Orlandi E, Baratè C, Canevari A, Brusamolino E, Bonfichi M, Arcaini L, Caberlon S, Pascutto C, Lazzarino M (2003). "Polycythemia vera in young patients: a study on the long-term risk of thrombosis, myelofibrosis and leukemia". Haematologica. 88 (1): 13–8. PMID 12551821.CS1 maint: Multiple names: authors list (link)
↑Berlin, NI. (1975). "Diagnosis and classification of polycythemias". Semin Hematol12: 339.
↑ 3.03.1Anía B, Suman V, Sobell J, Codd M, Silverstein M, Melton L (1994). "Trends in the incidence of polycythemia vera among Olmsted County, Minnesota residents, 1935-1989". Am J Hematol. 47 (2): 89–93. PMID 8092146.CS1 maint: Multiple names: authors list (link)