Erythromelalgia in a patient with thrombotic thrombocytopenic purpura.

Erythromelalgia is characterized by paroxysmal burning pain and redness of the distal extremities; primary and secondary forms exist. Secondary erythromelalgia is most commonly associated with essential thrombocythemia and polycythemia vera, and the pathogenic mechanism is thought to be platelet aggregation. Thrombotic thrombocytopenic purpura is characterized by thrombocytopenia, microangiopathic anemia, renal failure, and fluctuating neurologic signs and symptoms. The pathogenic mechanism suggested for thrombotic thrombocytopenic purpura is diffuse platelet aggregation. We describe a female patient in whom thrombotic thrombocytopenic purpura was associated with erythromelalgia. This has not been previously reported.