[Erythermalgias].

Erythermalgia is an unfrequent disorder characterised by recurrent, red, warm and painful extremities. Classification of erythermalgia is clinical: primary erythermalgia usually starting during childhood; erythromelalgia secondary to myeloproliferative disorders (especially thrombocytosis or polycythaemia vera); erythermalgia seconndary to drugs or vasculitis. Intravascular platelet activation and aggregation with plugging of the arterioles has been suggested as the mechanism of secondary erythromelalgia; aspirin is an effective treatment. Conversely, as yet unelucidated pathophysiologic events underlie primary erythermalgia, which usually fails to respond to aspirin.