A refractory case of secondary erythermalgia successfully treated with lumbar sympathetic ganglion block

A 59-year-old Japanese man with myasthenia gravis, who had a 10-year history of temperature-sensitive pain in the lower extremities, i.e. improved by cooling and worsened by warming, consulted us because the pain had become intolerable during the previous 4 months. Bilateral erythema, swelling and large ulcers were noted on the calves, dorsal aspects of the feet, and soles. Laboratory data showed thrombocythaemia and a positive antibody to the acetylcholine receptor, but were negative for antinuclear and antiphospholipid antibodies. A diagnosis of secondary erythermalgia was made because of the clinical features, the laboratory data, and the lack of family history of this disease. Although steroid pulse therapy, oral aspirin and antiserotonin drugs were ineffective, bilateral lumbar sympathetic ganglion block succeeded in relieving the severe pain and curing the ulcers. The clinical course in our patient suggests that sympathetic ganglion block may be one of the most effective treatments for secondary erythermalgia. Although the mechanism of this effect is uncertain, microcirculation disturbance in secondary erythermalgia, if any, may be improved by this block.