Long-term remission of primary erythermalgia with R1150W polymorphism in SCN9A after chemical lumbar sympathectomy.

Primary erythermalgia (PEM) is recalcitrant and long-term remission is difficult to achieve. Favorable results of treatment using carbamazepine or mexiletine have been identified in some PEM patients with SCN9A gene mutations. However, no therapeutic studies regarding patients without pathogenic SCN9A gene mutation have been reported. Here we present a PEM case with R1150W polymorphism in SCN9A and a five-year remission was achieved by chemical lumbar sympathectomy (CLS). A 15-year-old girl with severe PEM attacks in both feet and lower legs was treated with CLS and followed up for five years. The encoding exons and their flanking sequences in the SCN9A gene were amplified and sequenced. A 50% immediate pain reduction was achieved after CLS. Burning pain, erythema and swelling in the lower legs disappeared in four days, and all ulceration healed in a month. The patient resumed normal exercise five months after CLS. There were no relapses in the following five years. R1150W polymorphism in SCN9A was detected in the patient and her healthy father. Long-term remission was achieved after CLS in this PEM case with R1150W polymorphism in SCN9A. The effectiveness of CLS and phenotype/genotype of PEM should be further studied in larger samples.