PLATELET CONSUMPTION IN THROMBOCYTHEMIA COMPLICATED BY ERYTHROMELALGIA - REVERSAL BY ASPIRIN

The involvement of platelets in the pathogenesis of erythromelalgia, a frequent and characteristics microvascular thrombotic manifestation i n patients with primary thrombocythemia and polycythemia rubra vera, w as investigated by measuring the survival and turnover of Cr-51 labele d autologous platelets in 10 patients with thrombocythemia patients an d in 6 subjects with reactive thrombocytosis. The mean platelet surviv al time of the erythromelalgia patients was 4.2 +/- 0.2 days, which is significantly decreased as compared with asymptomatic thrombocythemia patients (6.6 +/- 0.3 days, p <0.001) and patients with reactive thro mbocytosis (8.0 +/- 0.4 days, p <0.001). The mean platelet survival ti me of asymptomatic thrombocythemia patients was significantly decrease d (p <0.001) as compared with reactive thrombocytosis patients. Treatm ent of erythromelalgia with aspirin increased the mean platelet surviv al time from 4.0 +/- 0.3 days to 6.9 +/- 0.4 days (p <0.001) and was a ssociated with an elevation of the platelet count of 216 +/- 30 X 10(9 ) platelets per litre (p <0.001). Coumadin failed to improve platelet survival or symptoms caused by erythromelalgia. The increased platelet consumption in erythromelalgia is attributed to the formation of plat elet thrombi in the arterial microvasculature. This conclusion is supp orted by the ability of aspirin to interrupt platelet consumption and clinical features of erythromelalgia.